Max_Power

Hi guys

I just got an Audi A6 2002 a month ago and now less than 1K miles later the car started to misfire.
The car currently has 63K miles and all the previous services have been done by the dealership.

I haven't driven the car since it started to misfire, but I put an OBDII reader and got the following codes:

4/10/09
17746: Camshaft position sensor
16684: Random/ multiple cylinder misfire detected
16688: cylinder 4 misfire detected
16687: cylinder 3 misfire detected
16685: cylinder 1 misfire detected
16815: Warm up catalyst; Bank 2:Efficiency below threshold P0421 code.

After reading the codes, I erased them and started the car (two days later). The engine was shaking (a bit) and I got these codes - 30 seconds since I fired the engine - while the car was idling. Of course I shut down the engine and currently I driving one of my other cars.

16684: Random/ multiple cylinder misfire detected
16688: cylinder 4 misfire detected.

Please let me know how I should approach on this issue - pointing out what might be the most obvious or cheapest things to change first.

Thanks
Chris

audiguy76

replace spark plugs first, then try coilpacks

Max_Power

I was thinking of doing that (and I might still do since it's cheap and easy) but what's the possibility that all of a sudden 3 different spark plugs got bad?
The same goes for the coils and injectors or cylinder compression.

Also it seems (from their number) that cylinder 1,3 and 4 do not belong in the same bank.

Is there anything that has to do with my failure and an effect on both cylinder banks?

I know that the previous day before this thing happened my gf was driving the car and left the gas tank go almost totally empty. I'm not sure if this can be related - unless if there is accumulated dirt that went through fuel filter and clocked some of the injectors (do you think that's possible)?

AUDIctivo

Swap your spark plug from Cylinder 4 to the 5th and see if the code follows it. Your ICM could have gone too. They are located on top of your airbox. There are two of them for each bank. I got the code for random/multiple misfire a week ago and it was because my ICM for bank 1 was shot. A new one is $190 plus shipping from Carson.

Good luck.

Max_Power

Hi guys

I put a new spark plug in cylinder 4 but nothing change.
so I got the usual:

16684: Random/ multiple cylinder misfire detected
16688: cylinder 4 misfire detected.

The today (5 minutes ago) I swap the coil between cylinder 4 and cylinder 5 and Bingo, the problem moved in cylinder 5!

So I got the codes:
16684: Random/ multiple cylinder misfire detected
16689: cylinder 5 misfire detected.

My question to you guys are the following:
1) What's the cheapest place to buy a new coil? Should I go with OEM or there is something better out there?
2) On the first time the problem was detected the error codes also showed misfire on cylinders 1 and 3. Do you think that these coils have also problem or since the engine was running rough due to #4 misfire maybe that led to the other misfire at that point?
3) From your experience do these coil fail often?

SloopJohnB@mac.com

1. OEM. OTOH, there ARE alts to BMW stock coils so it might pay to look around. There are high output coils available for the 1.8 and 2.7 turbos. http://www.nyxracing.com/okada-proje...6-p-29679.html has them for the 4.2....haven't tried them. Why don't you try eight of them and report back to us?
2. Stuff happens. Think horses, not zebras. Keep It Simple. I'd replace the one.
3. Not often enough to justify replacing all eight when one fails or all eight on a prophylactic or time schedule basis.

YMMV.

AUDIctivo

I agree with SloobJohnB in that I would replace only that coil and see what happens. It would be crazy if all of them went at once. As far as the brand, I would go OEM. Check out how much the coil pack with Carson. He has really good prices. When you install the new coil, see the codes, if you still getting that random multiple misfires on cylinder 1 and 3,...it might be that your ICM is shot too.

Like I said before, this just happened to me a week ago. I had a random multiple misfire code and misfires on cylinders 1 and 2. I bought a new ICM, installed it and problem gone!! Hopefully it is your coil! The ICM is $190 plus.

Good luck!

Max_Power

Thank you so much guys... I initially ordered 3 but I changed my order to 1.
I'm new to Audis and the only place that I found this item (coil) was at ECS tuning. The prices were right but I have to wait one week until the get the parts (even though were not backordered) and then probably another week until they get shipped from East coast to West coast where I live.

Do you know any online shop with Audi parts that is close to west coast?

Thanks
Chris

AUDIctivo

http://www.genuineaudiparts.com/

I think they are located in California. Hope it helps! Tell them you are AW member for discount.

Max_Power

Thank you so much!!!
I just canceled my order with ECS (placed on Friday expected to be delivered on Tuesday - 10 days later), and placed an order with genuineaudiparts!