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Discussion Starter #1
'99 A4 Avant Quattro 1.8T (AEB): To make a long story short, changed the oil, driving home, and CEL is flashing. Get it towed to Autozone, codes read, and towed home. Engine misfire in Cyl. 2, so I removed old plugs to find the electrode missing from cylinders two plug. A Bosch plug with three tips, and the electrode came off! Help said it probably flew out the exhaust, and we started switching coils around (Cyl. 2 to Cyl. 1, and Cyl. 4 to Cyl. 3). Got the car running, and stalled on the way to work next morning. Now it misfires on the cylinder 1 and 3 now, so we think it's a coil problem. Bought two new coils, and it immediately started misfiring again. The whole time throughout changing and testing there's something bouncing around in the engine. Pretty much exactly like throwing somethin at a fanblade while it's spinning. Maybe the electrode is bouncing off the Turbo, then getting sucked back by the exhaust to bounce off the turbo again. I'm not sure. All help is needed, and appreciated. TIA
 

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The oil is most-likely coming from worn valve guides, not piston rings---and the 1.8T has five vlves per cylinder. When piston rings are bad, the oil will show up on all cylinders--not just one. And don't worry about the lost electrode. It probably went out through the exhaust valves. Put in a new plug and have a compression test done.
 

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Discussion Starter #3
Is the car driveable for my wife to get to and from work? Her job is only 2 to 3 miles away. Are valve guides a special change, or can someone with mechanic understanding, and the ability to follow directions accomplish this? The auto hobbie shop has almost every tool you can think of. I'd really like to fix this myself, and maybe even put in one of those power gaskets I read about on here. I think Chas has one. Thanks for the feedback e36bmw! :thumbup:
 

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Put in the new plug and drive it. See if stops misfiring. If the valve guides are worn the new plug may get fouled again after a few thousand miles of driving. Replacing valve guides is not for the novice. It basically involves removing the head and having machine shop type work done. They will basically rebuild your head by replacing all valve guides, installing new valve seals and reseating all the valves.

I had a Mazda 626 that had heavy oil usage because of worn valve guides in one cylinder. It would foul out the spark plug about every 2000 miles. I just kept putting in a new plug every 2000 miles and drove it for another 40,000 miles.
 

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Discussion Starter #5
Changed the plugs today, and started it up. It ran fine, but the rpm's were bouncing between 800 and 1K. I shut it off, and start it again just to see if any problems might arise from another start, but it was the same. The CEL was still on, but there were 4 codes from autozone. Two were cylinder# 2 misfire, and the other two had to do with the pre-cat sensor. They are as follows P0134, P0302, P1196, and P0302 all in this order.
My wife and I go to get a movie, and I figure it'd be a good idea to take the A4, testing to make sure it's fixed. We didn't get far down the road when it started idling really rough. The same as it did on Friday, when the misfire and everything started. This time the CEL didn't start blinking right away. We didn't even get more than an 1/8th of a mile from the house, thank god, cause I pushed it back home with the wife steering. Maybe I should skip p.t. tomorrow morning....lol. This thing won't start or run. The battery light came on when it was stalling. I'm not extremely familiar with VW's and Audi's, but I'm thinking maybe an ignition coil or something. I think a VAG-COM is becoming a necessity when owning two used VW and/or Audi vehicles. Well, good luck to me, and I hope somehow to fix this with out using mechanics, dealers, or any shops.
 

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Don't know if Audi had the ICM problems that the early Passats had,but I would look into that.
I would also get a compression check and pull the #2 plug to see if it is coated in
oil already.
The front O2 sensor could foul due to the misfire or oil leak.
 

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Discussion Starter #7
thank you for the help. I'll try to get this all done tomorrow. If anyone else has some easy tests I can do buying some relatively inexpensive tools, please let me know. TIA
 

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This sounds very familiar :mad:. It is probably your ICM (AKA Power Output Stage). After losing the electrode from one of your sparkplugs, you should have your compression checked. What is your mileage? What type of plugs, and how long have the plugs been in your car?
 

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Discussion Starter #9
VAG'd it, and here's all the codes that came up:
P1602
P0134
P1196
P0300
P0302
P0300
P0302
P0304
Cleared them, and the car was running fine. Thought it'd be fine to drive to work, and it felt fine. Got about 5 miles away from my house and it started miss firing again. I pulled into a parking lot and got a ride to work. Had issues with tow truck service so it will be brought back tomorrow afternoon. Does anyone have any trouble shooting steps for these codes. Something is making it continually misfire, and it's not the plugs. It may be the Ignition Coils, but I ohmed them out, and they were just under 2000ohms. I need some help, this car needs to be running. I'll vag tomorrow if my help has the time. Hope for the help on here as well. TIA
 

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This is how may car ran with a bad MAF. Runs really poorly intermitently, black particulate stuff comes out the exhaust. The ICM can be tested with a multimeter - but now you are missing on three cylinders, so I am guessing MAF.

Don't drive it cause it will keep coming back and missing/dirty running is hard on it. MAF is a do it yorself job on a Passat - I would guess same on Audi. Get the part overnighted from internet source.

The information section has info on cleaning the MAF, which will show you how to get at it on a Passat. May be good to get you going.
 

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Definitely sounds like an ICM, especially with it being a '99. I saw those exact same symptoms. www.busdepot.com has the part for just over $100, assuming the Audi uses the same part (90% sure).

Takes 5 minutes to replace.
 

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Discussion Starter #14
The ICM tested fine. I need to vag the car again, just don't have access to it right now. I plan to build one, and have the write up already. Anyone that can think of anything else to check, please let me know. I'm guessing I'll give my MAF a cleaning. It's dark already, so that's tomorrow's task.
 

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Discussion Starter #15
switched coil 2 and 4 to 1 and 3, respectively. Now cylinder 1 and 3 are misfiring. I'm guessing this means it's the ignition coils. I'd like to get them offline since they are cheaper, but there is not return policy on electrical parts. Napa can get it for $64, which isn't too bad. I'm going to pull the coils and test them with a dmm again.
 

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Discussion Starter #17
I called the local Audi dealer, and they said there wasn't a recall for this. It's a '99 A4 with the AEB engine.
 

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Discussion Starter #18
Changed ignition coils, and..........still misfiring. To make it worse, it's the cylinders with the new coil packs. I'm going to do some compression tests, hopefully tomorrow. This is frustrating, anyone have ideas. The only codes are cylinder misfires.
 

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I agree with posPassat, change the ICM. The ICM must be bugging out. You mentioned that it would run fine for a few minutes, therefore when you checked it, it appeared fine or was fine.

A minute later it goes squirrely :weirdo: , cutting out.

Good luck...
 
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