I pulled My Audi Transmission and look What I found!!!!!  The pump seal was seperated from the pump.  No wonder all the tranny oil came out!!!!  All I have to do is pull this ring off the torque converter, press it, the funky looking washer, and a new seal back into the pump and I'll be back in business.  And Audi wanted $6K to install a rebuilt tranny!!!!

You think this was a little past its useful life ....... ???

http://mydrive.roadfly.com/blog/uploads/tmatern_heat_005.jpg

I have heat now!!!!!

Update:

84 BMW - 633CSI  Needs the Following:  Heater Valve Core replacement, Exhaust upgrade, and drive shaft balancing and she should be good to go for spring.

99 Audi - A6 - tranny has been pulled for pump seal replacement and should be up and running by spring.

http://bimmer.roadfly.com/bmw/forums/e24/8120884-1.html

Rebuilding Tranny on the new ride .........

so far - removed exhaust, 3 drive shafts, shields, starter, disconnect wiring, unbolted from engine, getting ready to pull the beast out

Pray to the 6er gods for me!!!!!!!

Update: Found a tranny manual for $80

New Radiator - Water Pump - Thermostat - Power Steering Pump-Hoses-Belts - ---- ----Ready for Winter Driving - Feels Good

http://bimmer.roadfly.com/bmw/forums/e24/8114219-1.html

Blew coolant hose on the New Ride  ---- details below

http://bimmer.roadfly.com/bmw/forums/e24/7957151-1.html

THE AUDI A6: kicking my A$$ already: A little tiny 4 inch long 5/8" diameter hose blew a leak .......it's a miracle it did not happen on the highway ...........was at my sister's house in INDY ......took off to go to the Indy Air show and red juice was all over the drive .....thought I blew the tranny .....but turns out to be pink anti-freeze in these AUDI'S .....was a real pain in the A$$ to fix it.

My new ride .........note hot babe modeling in front likes it so much she is glowing!

Screw backed out somehow - retightened and put thread lock on screw - good as new -  bearings ok!

MORE BABES

The procedure was for a different model BMW; however, I did use the first half of it: (i.e. removing Roundel) At this point don't take out the 2 plasitc black retaining doodads at 3 and 9 oclock that are pressed into the sheet metal of the trunk as the procedure descibes because you cannot jimmy the lock thru these holes. You have to remove the 1/2 inch round black rubber plug in the center of where the roundell was. If you use a mini flash light you can look in here and see 2 nuts welded to a backing plate at about 10 oclock and 2 oclock. These nuts are what the strike plate for the lock is attached to. Now take a BFH (Big F#$)ing Hammer and a Big F#$(ing Screwdriver. The biggest ones you can find that will work comfortably in this tight quarters. Place the tip of the screw driver on the nut head and give the screwdriver 4+or-2 hellaciaous strikes with the BFH. Do the same with the other nut (10 oclock or 2 oclock) which ever one you did not start with. You may have to alternate back and forth between them. What you have done is loosened up the strike plate in the locking latch mechanism. The trunk should pop open when you push the lock cylinder push button in. If not, repeat the above BFS and BFH procedure until it does. Now go back to the strike plate and adjust it according to how your weak lock springs work. Make sure you get it right the first time or you will be doing this whole thing all over again. Also, make sure the trunk lid does not pop open on you while driving. Note: Lesson learned: you do not have to touch the strike plate when replacing your roundell emblem on the trunk. THAT WAS ORIGINALLY ALL I WANTED TO DO(REPLACE THE EMBLEM!) If you do and you do not get it lined up correctly, you will be going through the bullsh*t I just went thru. Now I have to put my rear seats back in. LOL P.S. don't forget to replace the plug and the emblem.

A heck of a lot better way to go - My new machinist put in Toyota universal joints for me with internal rings after he machined the grooves in for me. He used UVs with external grease fittings after I told him how much I liked that he was putting UVs with internal grease fittings(he advised me I'd have to remove the shaft to lube) he went to the trouble of locating some that would work with external grease fittings (SAME PRICE!) - he also warrantied the job for 6 months or 6K miles - - - unbelieveable - needless to say I'll be going back to him for future work and I'll recommend him to anyone who needs his services - he took his time and did the job right - even though he thought he would have it done sooner - I did not mind waiting the extra couple of days -----what is really interesting is originally BMW told me when I wanted to buy a center support bearing that I would have to buy an entire new drive shaft ----and that was only $40 for the center support bearing (elsewhere obviously) ----then when I went back to BMW to get the UV joints they told me the same thing again but this time they told me you could only get center support bearings and you would have to buy a new drive shaft if the UV joints were going because they were staked in -----what a crock ------I now have a smooth running machine and I can lube her up any time i want(she'll love it) ----amazing but true! I'll post his shops info on my blog for those interested.
http://yellowpages.superpages.com/profile~SRC_msn~N_Automotive+Machine+Shop~PP_N~STYPE_S~T_Flint~S_MI~Z_~CID_99999999990~LID_7n5Noa+NpAEuQx/pBjAKZQ==~lbp_1.htm

My former wife just called me:  .....The elderly gentlemen, Bill, who I purchased my 6er from about 2 years ago just passed away this morning.....I'll miss Bill......he was a great neighbor, wonderful friend, awesome teacher, fellow BMW enthusiast and all round nice guy. 

 He was like a father to me.  I'm going to miss him. 

I know he was real lonely since his wife passed away a few years back.  He won't be lonely anymore.

You don't meet too many people like him in your lifetime.  He lived a good life and helped alot of people.  I am going to miss sharing all the car stories with him.  I can't believe he is gone. 

I am going to post this on my BLOG in memory of him and I am going to dedicate my BLOG to him from this time forward.

WILLIAM J. DRIESSEN, 83, of Fort Wayne, died Friday, April 28, 2006, at Heritage Park Nursing Home, Fort Wayne. Born in Dehehague, Netherlands Aug. 24, 1922, he was a toolmaker, retired from Industra, Fort Wayne, he was a member of Immaculate Conception Church. Surviving are son, Alex Driessen, Henniker N.H.; brothers, Jan and Cor Driessen, both of Holland; grandchildren, Jennifer of Newberryport, Mass., and Douglas of Salt Lake City, Utah. He was preceded in death by wife, Maria Driessen in April 2002. Graveside service is 1 p.m. Tuesday at Covington Memorial Gardens Cemetery. There is no visitation. Arrangements by Elzey-Patterson-Rodak Home For Funerals, 6310 Old Trail Road, Fort Wayne, Ind.
Published in the Fort Wayne Newspapers from 4/30/2006 - 5/1/2006.

Just did this job recently to re-do my Sunroof Headliner upolstery.

1. Leave your ignition off and use the manual Sunroof operation procedures (This will lessen the chance of significant damage to your drives worms): use the sparkplug wrench to loosen the large nut on the motor. Then use the allen wrench tool to open and close the Sunroof by turning the fitting within the large nut. Wedge the allen wrench in with some paper wadding or such to keep it from falling down every 15 seconds (drove me NUTS for a while).

2. Open the Sunroof. From outside the car, unscrew three screws from each side's guide rails and two screws from a bracket just behind them on each side as well. Make note of (mark) the position of the raised little ramp on each bracket. They are seperate pieces and will come free once you remove the brackets.


3. Carefully crank the Sunroof forward until it's just a couple of inches open and release the Headliner from it by pulling down on the front edge to release about six door panel type plugs/clips. Use of a strong, smooth, curved device to pry the clips away will prevent possible damage. Or just go to your parts store and buy a "Door Pannel Tool" (Approx. $8.00). Slide the Headliner all the way back.


4. Slowly closed the Sunroof. Remove three small nuts and washers from under each side of the Sunroof. They are arranged in a triangular pattern on triangular brackets. Release the brackets from the studs which are attached to the Sunroof. You may now remove the Sunroof by simply raising it from the inside and lifting it off from the outside. A second person used here or some nice shop blankets will ensure no uninvited "engraving" on your roof.

5. Pull the Headliner all the way forward. it will be attached to a transverse rail by a rod on each side. The rods can not be disconnected from the Headliner, but they can be disconnected from the rail by gently prying them down. A little clip and rod just disengage. You can now remove the Headliner.

6. To install: place the Headliner on its slides and snap the rod ends into the clips on the tranverse rail. (By the way, if you should have decided to remove the rail, remember to have the pointy ends facing forward when you re-install it.) Slide the Headliner all the way back.

7. Place the Sunroof back on the car. Before doing this, take the time to lube your rear seals, as this will be the last time you'll see them for a while (hopefull!) The end of the roof with "the little skis" on each side is the front. If you've moved the mounts just reposition them with the allen wrench crank. install the three mounting nuts and washers on each side.

8. This is a good time to adjust the Sunroof height if desired. The two screws that are attached to the sides of the triangular mounting plates are used to adjust the height of the rear of the Sunroof, which should be 1mm ABOVE the height of the roof behind it. The three screws across each front corner are used to control the front height, which should be 1mm BELOW the height of the roof infront of it. Loosen both sets of inner screws then turn each outer screw to adjust the height while pressing down on the Sunroof. Re-tighten the two inner screws on each side to lock the setting in. You won't believe the difference in Wind Noise a properly adjusted Sunroof can make.

8. Here's where my proceedures differ from the book's a little, but trust me THIS will save you mucho frustration. This extra proceedure is to re-engage the Headliner's followers with the rails on theSunroof itself, so that the Headliner follows the Sunroof when it's placed into the "Raised" position. Slowly, while pushing back on the roof to keep tension on the drive cables, crank the roof back far enough to re-install the guide rails and their three screws. Don't worry about the brackets yet. Now crank the roof about three fourths of the way forward.

9. GO WASH YOUR HANDS. Slide the headliner forward until the clips line up with their holes. A good pull on the front edge while gently pushing from inside will make this a bit easier. Snap all the clips home. Return the Sunroof to the full aft position.

10.. Being as you're in this "Mode", now would be a good time to remove the guide rails again and lube the rails and drive cables. My book recommends vasoline for the rails and light grease for the cables. Do this AFTER you're finished handling the headliner. This avoids the need for "Post Procedure Uphulstery Cleaner" to remove all your greasy finger marks. Replace the guide rails and brackets, AND their little ramps, returning the ramps to their original position.

11. Carefully crank the sunroof a little past full forward to make sure the headliner raises along with the sunroof. If it does, you're you're just about finished! Congrats. If it doesn't, return the sunroof to a "Closed" position, GO WASH YOUR HANDS, then disengage the headliner from the sunroof (Step Three above), slide it back, and pull it forward again while gently pressing upward on the rear of the headliner as it comes forward. Test the "Raised" position again. Done. (I Hope!)

12. Now re-tighten the large nut by the drive motor with your sparkplug wrench. It doesn't matter where in the cycle the Sunroof is, as it is the position of the drive cables that controls motor function. Turn on your ignition and see if it works.

GOOD LUCK,

Jim Moscardini

P.S. Can anyone tell me how to post to the Big Coupe Group? I'd like to put this experience along with "How to refurbish your Sunroof's sagging Headliner" into the technical library. THANKS - CIAO.

Repaired some rust spots on an old Buick many years ago and a buddy (former vocational body shop instructor and car restorer) of mine suggested galvaneal sheet metal as paint would adhear to it vs galvanized sheat metal. It worked then, but I am not sure where to get this stuff anymore(last time I got it at a place called Triangle Sheet Metal. It was easy to shape and bend and the paint adhered to it fine. Has any one used it? And does anyone know where to get it? It was easy to shoot sheet metal screws into and to pop rivets into plus it withstood alot of abuse ( i.e. rocks , dents, dings). I wanted to just skin the surface behind the doors of my sixer just below the trim after I cut all the rust and bondo (P.O). out and treat the exposed metal with rust extend. This solved all the rust problems with my old Buick back in the early 80's. It never reappeared and I loved working with this stuff. It was probably the easiest body work I ever did.

Yep, Galvanized by Hot-Dip Process  -  John in Simi Valley on 2006-04-05 at 21:24:39

The material Spec is ASTM A 653

The base material is generic carbon steel, low amounts of carbon for good weldability and stable aginst excessive corrosion. The plating is zinc which becomes the sacrificial material and will corrode before the base steel, so it buys you lots of time, especially when properly primered.

The sheets come in different ratings, most common are G30, G60 and G90. The indicate the zinc coating thickness, respectivly they mean .30 ounce per sq foot, .60 oz/sq ft and .90 oz/ft^2. obviously the G90 has better weathering characteristics, good for open air in salt spray environments.

The difference between Galvanized and galvized and galvannealed is the hot dipping process. Hot dip (into molten zinc) usually covers the sheet with a thicker, more robust coating for better rust prevention.

Weldability MAY be an issue. If prepped for groove/fillet welding by removing local zinc for MIG/TIG welder, can produce very good results. Be VERY CAREFUL with the gasses off the weld, the white clound is zinc-oxide, mostly harmless (non-toxic) but like breathing dust, can't be good. But more importantly, the blueish color is from the CYANIDE! Some reports I've read say it's okay to breath in small quantities, but I recommend a really good breather mask.

Spot welding thicker plated parts just sucks. The heavier zinc contaminated the weld too much for anything more than tacking.

Sources for this stuff: Any sheetmetal fabricator can get it, it's really common. May not be "off-the-shelf" at Home Depo.

Hope this helps!

Thank you very much! Thought I was losing it - Sharkbreath on 2006-04-06 at 18:05:36

The detailed information is awesome! I have engineering background but I am not a metallurgist and it has been awhile since the chemistry, however, I am familiar with industrial processes and this sounds like it makes alot of sense. I just had not heard of anyone using it for a long time. The last time I heard it was over 20 years ago and this was before the engineering courses. It just popped into my head after I started thinking about doing some simple body work on my 6er.

As I said earlier, I used the stuff in the early 80's and it worked fabulous. I did not have any problem with rust through and paint adhered to it wonderfully. If I remember right on my 65 Buick Electra 225 (Duece and a Quarter) it had extensive rust behind the rear wheels and below the trim line. I avoided all welding at the time by cutting a piece to fit perfectly with about a 1/2 inch extra on the top and bottom and primed it well. Then I removed the trim piece and sheet metal screwed the galvaneal to the remaining body metal that was not corroded(what was left after I cut out the corrosion with some sharp snips and a grinder). The tough part was meticulously priming the drill holes and screws and edges of the cut metal. I then folded the piece around the bottom and over what was left of the frame and weep holes. Then I sheet metal screwed it from underneath the car where it could not be seen. ( drilling holes through the thick steel was challenging also).

The trim covered the heads of the sheet metal screws nicely and you could not even tell the thing had ever had a rust problem. I remember this holding up nicely for 3 years in extensive snowy winters with plenty of salt on the roads. The paint never flaked. I finally blew an engine on I-5 going over the grapevine in Cali in the mid 80s. Sold it for scrap but it was still in good shape (with 180K miles on her).

It is funny and quite ironic that the spot right in front of the rear wheel wells of my sixer is almost an identical application that I will probably pursue this spring /summer. 20 year old cars gotta love em! Thanks again for the info!

Lift by diff: Always only to get it off the ground so that I could stick jack stands underneath of her. I never leave her up very long like that as she refers two steady studs (French connotations)under her anyway.....with all the normal driving stress loads I cannot see why this would put all that much more stress on the diff. We are talking basically a static load as compared to a dynamic load of immense force during driving. These are very robust cars and they take alot of abuse. I have lifted all of mine by the diff with a hydraulic jack and no blocks for better bite and less chance of wood spliting. They balance nicely from here and it is always easy to slide the jack stands in place quickly with the jack handle without getting under the car. I always back the jack off slightly but leave it in place for added safety. If I do need to take the wheels off I always place them strategically under the frame of the car in case there is some kind of failure. Always better to be cautious. It would be interesting to see a stress analysis of this loading; however, I don't think it would be needed. If there are differential problems it is more than likely caused by dynamic loads, etc. Should be very unlikely caused by the nearly static load of lifting.

Mine actually fell apart when I took it out to trouble shoot. Took me an hour to figue out how to put her back together (trial and error). It's a lot of fun taking out and putting in multiple times. Standing on head with your feet sticking out the sun roof. You know what I mean. I finally bought a new one as I could never get it to start without a remote trigger starter switch attached to the solenoid. It would turn freely and provide juice to the appropriate places allowing me to trigger start it, but other than that it was shot. Lots of little contacts prone to wearing out. I think alot of guys on this board have reported having trouble with them. Any way the new switch took care of things. I never had to replace the housing. Although I cannot promise you will not have to.
http://home.bellsouth.net/p/s/community.dll?ep=16&groupid=160912&ck=

http://member.rivernet.com.au/btaylor/technical.html

I performed the recommended rework on my AFM (i.e. soldering the jumper wire and repositioning the wiper assembly of the potentiometer to creat a new contact surface)  turns out my problems were associated with the coolant temp sensor circuit at the coolant temp sensor connector (loose solder connection on resistor inside the boot of the connector).  Details associated with this and some of the research is posted in my blog.  When you are doing the AFM rework one thing that you want to make sure to do is pre-tin the areas you want to solder for better solderability.  That is: the jumper wire ends and the two surfaces you are soldering them to(heat them up and melt some solder on them first individually.  Then reflow the solder while you hold the joint together.  You do not even have to use additional solder when reflowing as mine has held up fine for 30K miles.  My solder joint broke the first time and obviously I had to do it over because I did not do this trick properly.  It takes a little practice (try it on some scrap wire/component first a couple of times).  Also, the tie wrap trick for providing some lead strain relief for the solder joints is a good idea.  Be sure to seal the black cover after reworking the AFM with some RTV sealant to prevent water penetration from ruining your work as $600 for a new AFM unit is steep.

http://frwilk.com/944dme/afm.htm

What is best way to change rear BMW emblem? - Sharkbreath 2006-01-31 21:17:21 (91 views) (304 thread views)

I use a large plastic zip tie. (nt) - Patton '88M6x2/'00M5/'83 B9 Alp 2006-02-01 07:57:22 (46 views)

high strength fishing line? - SharkBoy 2006-01-31 23:33:57 (60 views)

fishing line is what I used but I needed - Taylor '85 635CSi A 5 Sp. ©¹⁴ 2006-02-01 07:21:05 (62 views)

carefully go behind the inside trim of the deck - Gene(AKA Just Gene) ©³³ 2006-01-31 22:44:59 (74 views)

Once you get a little room, with a very small scewdriver push into the holes and gromets. As I remember it worked for the front one also. This procedure did not work for my E32 though.

You have to be careful of the paint... - Romney88635 ©³ 2006-01-31 22:34:51 (56 views)

But the roundel is already toast. :)
I dremeled a couple big slots in mine and grabbed it with some horse shoers nippers. Prying around the edges is fine if your trying to save it... a needless risk if you're not.
Sometimes you run into double sided tape. - Lars Olbimmerguy 2006-01-31 22:16:23 (59 views)If the emblem has been off before, someone may have added double sided trim tape to strengthen the hold on the body. Follow previous instructions re two pins into nylon barrel grommets, but you may also have to run some nylon cord or floss between the pins under the roundel to cut the double sided tape. Try to find replacement nylon barrel grommets. The old ones get stretched out and that's why some people use the double sided tape as a lazy way to avoid replacing the nylon grommets

Use a small screwdriver to pry up at... - John in VA 2006-01-31 21:36:59 (69 views)

I'd go w a towel instead of a credit card (softer) (nt) - Kaiser 85 M635CSi/85 325e...er...lol 2006-01-31 22:12:09 3:00 & 9:00, after you put an old credit card down around where you're prying to keep from damaging your paint. Then you can grab the emblem with your fingers. Be sure to get 2 new grommets as well.(34 views)

Hey! Thank you All for the Input!!!!!! Good Advice - Sharkbreath 2006-02-01 00:21:24 (33 views)

When I keep hearing the same symptoms as I encountered (granted I encountered alot of various symptoms) I always cringe and grit my teeth.......it definitely sounds like something electrical ....probably the same thing or version thereof....

I know not all the sixers had the resistor inserted into the coolant temp sensor circuit .... however they do all have that circuit ....the one that helps the ecu decide just how much fuel the injectors should deliver based on coolant temperature .......Read my blog!!! If this circuit is intermittently open because of wiring and or connectors......you will have a whole host of symtoms including these described.....

BMW did a nice job of engineering for changes in fuel atomization at different temperatures .....BUT.....this introduced a control loop in the system that gives us fits as these cars age .... brittle connectors and wiring.....the problem is nothing was engineered to retain the wiring integrity thru the life that these cars are seeing.

I am not sure that anything more that what was done could have been done. It has been shown in the aircraft industry that attempts in the early 90s to seal out moisture with shrink sleeve tubing and rubber boots over the electrical wires is not fool proof. Moisture will find a way to get in and once it is in there when the seal is tighter (shrink sleeve and rubber boots) it is even harder to get out....high temp low humidity baking it out is the only way.

The problem is these circuits are in one of the most vulnerable places ....the engine compartment....all kinds of chemicals, moisture, heat, cold, vibration ......corrosion .....loose fitting connections .....etc. In addition this circuit is highly likely to be disturbed time and time again in just our routine maintenance procedures not to mention shutting the hood ...the heavy doors ....

any little shake would set my coolant temperature sensor control loop off and depending on what time of year, cold, hot, humid, not humid ....rough roads different idle speeds causing different oscillations and frequencies of vibration that the weak link connections are subjecct to you would receive different symptoms ....which always will lead you to a different part of the manuals or archives thinking that it is this component or that

....and by the time you replace all of these and each time you have jostled enough things around in the engine compartment to introduce another variable in the equation .....you have spent a bunch of time and money not to mention some aggravation.

Your Symptoms Sound Very Similar to My Symptoms?:

POs experienced very infrequent symptoms of feeling like running on less than 6 cyls......I experienced very infrequent idle problems over a 6 month period after I acquired the vehicle.....mostly highway miles so it happened about every 100th traffic light when stopped ..... then as I tried to shake the bugs out the frequncy increased....always thought it was cheap or low octane fuel.......finally stalled a few times and no started a few times .....ignition switch finally went, but i could start her remotely (wired trigger remote).

I shook so much of the wiring around when I was trouble shooting the no start due to the ignition switch that I increased the frequency. So now she would start with the new switch but ran like crap.....most of the time....however sometimes she would run good.....tried everything.....fuel filter, both fuel pumps, fuel pressure regulator, voltage regulator, coil, cap, rotor, plugs, throttle control switch, computers, ICM module, relays, alternator, ground cable, afm rebuild .....all to no avail.....in fact the more i did the worse it ran.....intitially I had checked the CTS (coolant temperature sensor) everything checked out okay. Resistance values corresponded to specs at various temperatures. However, i discovered that there was an intermittnet open circuit in the CTS circuit at the connector from the wireharness to the CTS right on top of the engine and right in front of my face all the time. If it were a poisonous snake i'd be dead right now.

The wiring looked okay intially even the open shrink sleaving with the resistor soldered into the circuit about 2 inches back from the connector. solder joints looked good as did the wiring.....resistor according to my research had been installed on 84 - 633 CSIs post production I believe at dealers to correct a lean condition. I noticed that resistor was further up the wire harness and in the shrink sleeving not in the boot on the connector as described in the research. I always kept going back to this point....as it looked suspicious all along but now my curiosity and desperation kicked in the survival skills so I took my razor blade out and carefully slit the rubber boot that covered the connector wire harness transition and as I gingerly removed the boot, behold an even smaller resistor appeared and the wiring, solder joints, resistor, and resistor leads practically dissentigrated in my hands as the 20 years of corrosion within the confines of the boot(not completely moisture proof by the way)caught up with her.

The resultant intermittent open circuit caused the problems all along. Any open circuit or partially open circuit in the CTS loop of the ECU feedback system is going to cause these type of problems .....so check the wiring, connections, etc. very carefully.....I would recommend using a continuity meter and checking the entire lenght of the harness while simulating vibration conditions by shaking the wire harness around. I think this circuit is the culprit to many of the problems experienced on this board as the symptoms are always the same and the attempted solutions always seem to be unfruitful or only temporary ....just shutting the hood on this vehicle is enough to jostle this circuit into performing correctly or incorrectly....amazing but true if you have a loose wire or slightly corroded connection .... Check it out to be sure!

Note: Highlighted are sections that I used in trouble shooting my vehicle for coolant temp sensor circuit problem

Underlined section I know we have proved incorrect with our experience in the open circuit situation with the Coolant Temperature Sensor Feed back Loop .........therefore it is NOT a Fallacy.

Not Sure Who This Is ....But I'd like to meet him someday ...... heck of smart guy to come up with all this!!!!

Idle FAQ
by Sam Chien-shin Lin.

Last Update: 29 August 1995

-added fuel pressure regulator, cold-start valve, and 1-wire O2 sensor

stuff

I decided to put this FAQ together in the hope that others won't have to suffer the many hours of frustration and hopelessness I went through just to get the car to idle! The info contained herein was obtained from many sources including what I learned from my toils, Bentley, and snippets sent to me by other Bimmernetters (sorry I can't cite sources - there were too many). If you have any additions or corrections, please send them to me. DISCLAIMER: my own experiences were based on my '85 325e and '84 528e, and a friend of mine's '86 325es, so any references to other models are based on info I couldn't verify myself. Many thanks to all who provided information. Hope y'all find this helpful...

Sorry I couldn't cover other years/models, but as it is, writing this up took several hours as it is. The info contained herein applies to models w/ Motronic units prior to 1.1 (which eliminates the ICM and controls the ICV directly). Models covered include 1982-87 5 and 3 series.

After writing this, I found out that a similar FAQ had been added the WWW server. I've appended it after my FAQ.

-Sam

sam@cmd.com

TechFAQ: The Idle Stabilization System

1. Idle System Overview

In a conventional idle system, idle speed is controlled setting a baseline throttle opening. The idle speed is increased by increasing the throttle rest opening, and decreased by decreasing the throttle rest opening, usually via a throttle-positioning set screw.

With the idle stabilization system, the throttle is completely closed at idle; instead, air gets into the engine via an electronically controlled bypass system. Air for the idle system is obtained via a hose tap in the intake boot upstream from the throttle, and fed into the engine through a manifold tap next to the cold start valve. The idle speed is controlled by modulating the amount of air which bypasses the throttle via an electronically controlled closed loop stabilization circuit.

air filter --> airflow meter -----> throttle ------ manifold --> engine

                               |                        ^          |

                               |----------> ICV --------|          |

                                             ^                     |

                                             |                     |

                                            ICM <- input signals --|

Engine input signals and feedback allow more accurate control of idle speed over changing ambient air pressure, temperature, etc. (and hopefully, reduced emissions).

---> Note that the idle system gets its air _downstream_ from the air flow meter! The air is _metered_ so the DME knows about it!

The heart of the system is a small brain box, called the idle control module (ICM) (or idle control unit (ICU)), which takes engine signals as inputs. Although the ICM works in concert with, and shares some inputs w/ the Motronic (DME), there is no direct electrical communication between the two systems. The sole output of the ICM is a control signal which modulates a solenoid operated valve (the Idle Control Valve (ICV)). The ICV in turn adjusts the flow of bypass air through the idle system. The DME responds to the idle system via the air flow meter and its effects on input signals, such as engine RPM.

From the above description, a common fallacy about the idle system is instantly dispelled:

Fallacy #1: An idle system malfunction can mess up the mixture and destroy my oxygen sensor or catalytic converter, costing me mucho dinero.

Repudiation: Fallacy #1 arises from the notion that somehow an idle system malfunction can result in richening of the mixture, thus resulting in destruction of the O2 sensor and cat. However, _all_ air through the idle system is _metered_ by the air flow meter. Also, there are _no_ electrical outputs passed from the ICM to the DME. Therefore, the idle control system can only affect the idle mixture to the extent that changing the idle speed can cause the DME to vary the mixture.

Salient Points: Your mechanic is full of sh--. Experimentation with the idle system won't destroy your car in some unknown way. The only way you can directly change the idle mixture via the idle system is to introduce a vacuum leak (which results in _leaning_ of the mixture). The only thing that can cause a rich mixture is a malfunctioning DME.

The ICV control signal appears to be PWM (pulse-width modulation), meaning that the ICM varies the duty cycle instead of the voltage to change the valve opening.

2. ICV Overview

The ICV is a dark plastic or silver-colored metal cylinder 3.5" long and 1.5" in diameter mounted on top of a two-legged support bolted to the valve cover near the firewall. An intake hose gets air from a tap on the side of the intake boot between the air filter and the throttle (the intake fitting is directly opposite the electrical connector). The output is at a right angle to the intake, and feeds to a short 2" hose, which in turn feeds into the intake manifold next to the cold start valve. A black plastic two-pin connector feeds control current to the solenoid-operated valve flap with the ICV.

When there is no current, the valve is completely open. Increasing the current decreases the opening. The solenoid valve in the ICV does not entirely control the air flow though it; an adjustable bypass system within the ICV allows air to flow through it even when the solenoid valve is completely closed (hmm...a bypass system within a bypass system!). When the adjustment screw on the side of the ICV is turned all the way clockwise, no air bypasses the solenoid valve; turning it counterclockwise increases the bypass air flow.

----> The adjustment screw analogous to throttle position screw in a conventional idle system. Opening it up is like cracking open the throttle.

Bentley describes adjustment of the ICV screw as "adjusting the ICV current." In reality, the adjustment screw only indirectly affects the control current to the ICV because the ICM reacts to the RPM fluctuation caused by the change in idle air. When you open the screw, it lets more air bypass the valve, increasing the idle speed; the ICM responds by increasing the duty cycle (current) to decrease the ICV opening.

Bentley also says that adjusting the screw isn't supposed to affect the idle speed. I haven't found this to be the case (even when borrowing my friend's working ICM and ICV), so don't be too alarmed by it.

ICM Overview

The ICM is made by VDO. It is a 2"x2" box located above the glove box, to the left of the Motronic unit. To access the ICM, open the glove box and remove the black plastic upper cover (two phillips screws facing you at the junction of the dash and the cover; two black plastic retainers, in the back - rotate and remove). The big box w/ the large connector is the DME. There are different colors of ICM: solid black, black with a green stripe, and solid green. Black is the oldest. The solid green one it is the latest update (the one you want). The ICM is held in by a single bolt, and a 2x6 12-pin connector is connected to it. The pin numbers are clearly marked on both the ICM and the connector:

1) ICV (output)

2) Power supply

3) RPM sensor

4) Ground

5) ICV (output)

6) Coolant temperature switch

7) Automatic transmission range switch

8) N.C.

9) A/C switch

10) Air temperature switch

11) Coolant temperature sensor

12) Throttle rest position switch

All of the signals are inputs except the ICV outputs.

Inside the ICM is an analog circuit mounted on two circuit boards w/ a flexible connection. The circuit consists of an assortment of resistors, capacitors, op-amps, etc. Its job is to decrease the duty cycle of the ICV signal when RPM's dip and increase it when RPM's rise, contingent upon its various other inputs. Sounds like a pretty easy task, doesn't it? Why it doesn't do a better job is a puzzle to me. It seems like any idiot could design a better circuit. For one thing, the ICM can't seem to compensate very well for changes in ICV friction (that's why it's a no-no to clean or lube the ICV! It'll mess up the calibration and the stupid ICM won't be able to control it right!).

4. Troubleshooting

Of course, the easiest thing to do is buy a new ICM and ICV but that costs a lot of buck$ - about $300 from my sources. Getting used stuff from a yard might seem tempting at first, but bear in mind that the ICM is a delicate electronic circuit that overheats easily (that power transistor doesn't have a heat sink!), and the ICV can appear to function correctly, but still be out of whack. If you want to buy a used ICM, at least get the solid green one, because it's supposed to be the most reliable. Even if an ICV passes electrical tests, it could still be out of calibration. Personally, I think it's playing Russian roulette to buy any parts that you can't verify are good. If you're lucky enough to have a good friend who will let you borrow his/her *working* ICM/ICV, that's the best bet for testing, of course.

It's probably a good idea to make sure the car is tuned up, the air filter is clean, and the fuel filters and injectors are clean, etc. before proceeding w/ the diagnosis. If your motor is too out ofwhack, the stabilization system probably won't be able to compensate.

DON'T CLEAN THE ICV W/ GUMOUT OR WD-40! It just might change its friction enough that the ICM won't be able to control it anymore.

Vacuum Leaks

First, look for vacuum leaks! Vacuum leaks introduce unmetered air, causing a lean mixture and rough running.

• Is your oil filler cap tight?
• Is your oil dipstick tight?
• Any cracked vacuum hoses or loose connections?
• Any cracks in the intake boot?

One good trick is to spray a little carb cleaner where you suspect a leak. If the RPM's change, then you know you've found a leak.

Throttle Cable

If your idle is too high, make sure your throttle is really closed at the rest position. On my 325e, the previous owner had adjusted the throttle cable so that the throttle was cracked open when my foot was off the gas pedal.

To adjust the throttle, take off the intake boot. Adjust the cable until you can just barely slip a .0015" feeler gauge between the throttle plate and the throttle housing. The purpose of this tiny clearance is just to prevent the throttle plate from gouging a groove into the housing. After adjusting the throttle plate, don't forget to recheck the throttle rest position switch; you may have to readjust it. See below for a description of how to do that.

Fuel Pressure

A bad fuel pressure regulator can cause the following symptoms:

1) rough idle

2) running rich (black smoke) - this can cause black soot on your spark plugs

3) buzzing noises from the fuel pump which may vary w/ engine speed

4) general lack of power

My 528e manifested the problems only when warm. It ran fine until the temp gauge got in the the mid-range, and then would not idle the next time I got to a red light. Then it would lose power and wouldn't idle. Large clouds of black smoke and power loss ensued. Interesting thing, too, was that the car wouldn't stall as long as I left the A/C running - I guess the idle circuit's compensation for the extra load of the A/C did the job (TIP: if the car won't idle, try turning on the A/C!). At first, I thought it was a bad transfer pump, because the fuel pump would buzz loudly once the car was running badly, varying w/ the RPM's.

Lacking a fuel pressure gauge, and being the buffoon I am, I swapped out the transfer pump, main fuel pump, and cold start valve from my 325e, as well as replacing the oxygen sensor before I realized the fuel pressure regulator was the culprit. Then, reading the old digests from the list, I found a posting which mentioned the fuel pressure regulator as a possible cause (READ THOSE OLD DIGESTS!). Voila, w/ the new regulator, it runs perfectly now.

For the '85 325e and '84 528e, the regulators (last 3 digits of part number are 225) are rated at 2.5 bar; most regulators have the rating stamped on the side. I won't go into detail here about checking it, but suffice to say that if it's way off spec, your regulator is bad - you can e-mail me or consult Bentley for more details on test procedures.

The fuel pressure regulator is located at the front of the engine, and is attached to the front of the fuel rail. It's easy to identify as a brass colored metal cylinder about 2" in diameter it has a fuel hose going to it on one end, and a vacuum line on the other end which goes to the manifold. If you see other metal cans in the fuel line w/ fuel hoses coming out of both ends, those are vibration dampers - they cut down on fuel pressure variations caused by the injectors opening and closing.

The vacuum line is attached to a diaphragm in the regulator which allows it to adjust itself according to manifold pressure. To check the diaphragm, unplug the vacuum line from the regulator and plug the hose w/ your thumb. You should see a change in the pressure (or if you don't have a pressure gauge, you should at least see a change in idle speed). Alternatively, you can unplug the hose from the manifold and suck on the end of the hose. If you can't build up a vacuum, then the diaphragm is leaking and the regulator needs to be replaced.

Cold Start Valve

The symptoms described above (except for the fuel pump buzzing) could also be caused by a bad cold start valve. The cold start valve is an extra fuel injector which is mounted on the intake manifold, usually above the valve cover. There is a two-pin electrical connector going to it, as well as a fuel feed hose. The valve is supposed to inject a little extra fuel into the engine to help cold starting. Controlled by the thermo-time switch, it's supposed to shut off after a few seconds. A worn valve could constantly drip fuel, causing a rich mixture.

To test it, unbolt the two allen bolts which affix it to the manifold, plug the hole in the manifold, and have someone else start the motor while you observe the cold-start valve (leave the electrical connector attached). If the motor is cold, it should spray for a few seconds and stop. If it's hot, no fuel at all should emanate from it.

If it keeps spraying forever or drips, either the valve is stuck on or the thermo-time switch is stuck on. Disconnect the electrical connector. If it keeps spraying or dripping, the valve is bad. If it stops, then the thermo-time switch needs to be replaced.

NOTE: check the fuel feed hose to the cold-start valve for cracks while you're at it. On both of my cars, it started to drip fuel on my valve cover. Lucky I discovered it before the engine blew up!

ICV Diagnosis

NOTE: The diagnoses below don't all make sense unless you follow the steps in the sequence shown.

1) Turn the ignition key to run position, but don't start the car. You should hear quiet buzzing sound from the ICV, and if you touch it with your fingers, a vibration. If not, either the ICV is bad or there is no control current.

2) Start the car. Run the system "open loop" by pulling the electrical connector from the ICV. The RPM's should climb to about 1500-2000, and then oscillate back and forth between about 600-1500rpm. If reconnecting the electrical connector has no effect on RPM's, your ICM is probably at fault. (For the curious, your RPM's fluctuate because when the ICV is disconnected, the valve is stuck wide open, and the DME is the only thing controlling your idle. The RPM's rise until it cuts the fuel flow, which causes RPM's to dip. Then it restores fuel flow, and the cycle begins again.)

3) Cut the motor. Pull the electrical connector from the ICV and connect an ohmmeter across the terminals. The reading should be about 9-10 ohms at temp 73+-9F(23+-5C). If you get an open circuit, it's time for a new ICV. If the resistance is much lower, you've got a short, and your ICM may be roached too, from the resultant excessive current draw.

4) Disconnect the ICV hoses, and look into the outlet. Obtain jumpers and connect 12V across the ICV terminals. The valve should close tightly when voltage is applied, and open strongly when the voltage is removed. (Yes, it might look grungy and black in there, but resist the temptation to clean it w/ solvent for now - it could throw it out of whack!). If there is no movement or the movement is sluggish, your ICV is bad.

5) Plug in the ICV electrical connector and turn on the ignition (engine not running!), all accessories turned off. Looking into the outlet again, the valve should be partly closed. If the valve is wide open and there is no vibration, you aren't getting any control current. To verify, unplug the ICV connector, and verify that you're getting voltage across it. If there's no voltage, your ICM is at fault.

6) Reconnect the ICV hoses and electrical connector. Hook up an ammeter in series the ICV. W/ the engine fully warmed up and idling w/ all accessories turned off, the current should be between 400-500 mA. If the current is wrong, adjust the ICV current. Turn the adjusting screw until you get 460+-10 mA at 700+-50 rpm.

KLUDGE: If you can't get the current in the proper range, just try to adjust the screw until your idle stabilizes at 700 RPM and ignore the current reading.

If you can't adjust the control current properly, proceed to ICM Diagnosis. If the ICM checks out ok, then the ICV is probably out of whack. Maybe an ICV Kludge can help you peg the diagnosis (or fix the problem well enough for you to live with it).

ICM Diagnosis

First, check to make sure the ICM is getting the proper input signals.

Checking the ICM Inputs

Disconnect the 28-pin connector from the ICM, and perform the following measurements on the connector with the ignition on.

1,5) ICV

This is actually an output (the only one). These two pins connect directly to the ICV. Hook up an ohmmeter between pins 1 and 5. You should get 9-10 ohms, the ICM DC resistance. See ICV testing section for more details.

2) Power supply

A voltmeter hooked up between pins 2 and 4 should read battery voltage.

3) RPM sensor

Hook up an LED test light between pins 3 and 4. While cranking the starter, the light should flicker.

The resistor is connected in series with the LED, and alligator clips are connected the resistor and LED leads.

alligator clip >>--------------|>----------<< alligator

                  1-2K ohm          LED        clip

4) Ground

Use a continuity tester between pin 4 and any unpainted part of the chassis. There should be almost zero resistance.

6) Coolant temperature switch

Measure continuity between pins 6 and 4. It should be open below 86F(30C) and closed above 118F(48C). If it doesn't close, check the connection at the switch. The temperature switch is mounted on thte cylinder head coolant outlet, to the front of the thermo-time switch. It is the only sensor in that area which has two separate push-on spade terminals. The brown wire goes to ground and the white wire goes to ICM pin 6.

7) Automatic transmission range switch

Hook up a voltmeter between pins 7 and 4. With manual transmission, should get battery voltage. With auto transmission, should get battery voltage w/ gear selector on Neutral and Park positions, 0V in other positions.

8) N.C.

9) A/C switch

A voltmeter between pins 9 and 4 should read battery voltage when the A/C is turned on, zero when the A/C is off.

10) Air temperature switch

Voltmeter between pins 10 and 4 should read battery voltage below 18F(-8C) and 0V above 39F(4C).