I got off work this morning and headed straight to my mechanic,on the way,it seems to not shake or vibrate,no needle jumping,then i pull up in front of my mechanic's shop,he tells me to go around the other entrance,so i went to drive around the block,so i said to myself,lemme try and trigger the issue,so he can see what i'm talking about,so i floored it,turbo wirling and all,i hit a left and there it was,check engine light wasn't just on but it was blinking

That's the kiss of death so i pulled in the lot and told him that the check engine light just came on blinking for the very first time,since i got my TMC module replaced,(which is working perfect by the way)

So he connected the scan tool,then opened the hood and took off the gasket gover and made sure all the coil covers were pressed all the way down and said"if it happens again,you need to get a new coil,its causing a cylinder to misfire. he said they cost about 40-50 dollars each,he also said if i wanted,i could get the spark plugs replaced.

so there you have it,that is the cause of all the strange symptoms

so i guess i can buy a "coil" from autozone? is 50.00 about right? let me know...

 

I don't know if you can get one from autozone, but they are ~$40-50. I had a misfire on my engine (cylinder 2) and I bought a new coil because that's what I was told the problem was - wrong.

If the misfire happens on a specific cylinder, swap the coils and see if the problem goes to the new cylinder. If it doesn't, you could try swapping your fuel injectors to be sure the problem isn't that either (could indicate bad injector); this happened to me, except it was a full blown misfire (CEL on and continuous rough idle). My problem wasn't the coil, spark plug, or injector - it was a $100 piece called the 'ignition control unit' near the air filter sitting under the plastic cover to the left of your engine.

My advice would be to do the cylinder isolation before pulling the trigger on a coil pack; you could save yourself $50, unlike me who bought a coil pack AND a spark plug AAAND an ignition control unit which was the only problem

I'm not trying to take anything away from your mechanic, but this may not be a problem he is very familiar with.

By the way, this problem is stickied on this forum under "Do you have a CHECK ENGINE LIGHT?"
I know this may not be the exact same problem you have, but you should not let this go unnoticed - circuits have the potential to fail slowly too, they don't always just fizzle out instantly.

 

Thank you for your take on my situation,i needed someone that had a similar issue. I'll bring this to my mechanic's attention,even though this guy only works on german cars at a dealership that sell mostly german cars,the dealership has 4 audi a4's sitting in the lot right now,even a S4 too! they get the cars from a auction,then if they need to be worked on,my russian mechanic "alex" is the man. the owners are Russian btw

 

Yep, I had my ignition control module (ICM) go out a few weeks ago. Bugged the **** outta me. But the car ran REALLY rough. Cylinder two misfire is the cause. I would try a couple things: Swap the misfiring cylinder's coil pack (big black square thing on valve cover) with another one. When the car is re-scanned see if the misfire moved. If so, bad coilpack. If not, try swapping spark plugs. Again, if it moved its a bad plug. If none of these indicate what the problem is and its not the ICM (cylinder two misfire) THEN you should look into the fuel system as this is the most costly repair.

I'm not sure the dropping revs could be attributed to misfires, but it never hurts to try. As for regapping your plugs, there have been a few discussions on the subject of spark plug gap. In a nutshell: Audi undergapped the plugs stock for longevity, that is they knew under the stress of combustion plugs do begin to expand. This under-gapping works fine but it has been proven that on a stock tune the engine runs more effeciently, more smoothly, (and makes a couple extra ponies) with the larger gap I previously mentioned. Its an easy to do job if you've got three tools: Deep socket wrench, extension and spark plug gapper/feeler gauge. Go down to autozone and they'll hook you up, the gappers are only a buck or so and DONT FORGET TO BUY ANTI-SEIZE!

 

I bought a coil at autozone for 29.99 my mechanic replaced it yesterday but it still does the same thing,i tried to make it throw a check engine light by going fast on the highway but it didn't throw it,the transmission doesn't shift as fast as it did before the replacement of the new coil or maybe since this issue took effect.

now i have to wait until my cel comes on,so i can continue my process of elimination. I even asked him to do as you suggested,to swap the new coil on another bank,to see if it misfires on a different cylinder,then see if its the coil and not anything else.

I think i should have just swapped the coil that was on the cylinder that was misfiring onto another bank,just to see if it was indeed bad?

what gap size should i suggest my mechanic perform on my spark plugs,once i get them? 0.32? or 0.28?

 

anyone?

 

Yeah,it was a bad coil that was causing my RPM needle to jump down and the engine to shake,replaced a coil on the 3rd cylinder and the issue went away.

Thanks for all the advice fellas ^_^

 

.032"

 

I have a 98 2.8 v6 non-turbo manual. I have the same issue. I am going to replace the coil, I already bought it but returned it when I replaced the wire cause it fixed the problem, temporarily.

Also... Is the spark gap the same for my motor or is it only for the 1.8?

Thanks.

Also... My air stopped blowing and the air controller is glitching out by having the fan speed moving up and down real fast but no air, at all. Could you tell me if the blower would cause this or if its the air controller itself or link me to where I could find this info.

Thanks again.

 

I think its your blower,or maybe the fuse that works the blower?

if you are experiencing the same issue as i did,with the RPM needle jumping down and the engine shaking,throwing a cylinder misfire,then i'd check for bad coils first,then if that doesn't fix the issue,i'd check for bad spark plugs,then ignition module.