140,000 miles. Was running fine, then out of the blue started running rough and sputtering at low rpm, smoking, and not accelerating properly. No CEL. Starts fine and runs. Has new plugs.

The ideas I have seen so far are bad coils or bad icm. Anything else to check?

Is there any way to know if a coil is bad other than replacing?

thanks to all for any tips.

Kevin

 

Where are you seeing the smoke come from? What color is the smoke? Do you have any service info from the last 15k or so miles that maybe worth mentioning? Valve cover gasket replacement? Transmission work?

Also, if you had an issue where a spark plug / coil was causing a misfire, you would more than likely have a CEL (Either persistent or flashing).

 

thanks for your input. here are the answers to your questions.

white smoke from the engine passenger side.

the valve cover gaskets, spark plugs and driver side cam tensioner were replaced in last 15k.

no trans work at all.

I had a suggestion that the vacuum hose causes this a lot. the suggestion said 9/10 times they have run into this the vacuum hose was the issue.

 

I hate to say it, but it sounds like your white smoke issue is from a failing cam cap / seal. Do you know if these were done as well when the valve cover gaskets were done? If not, I'm sorry to say that most of the work will have to be redone again if this is the case. You can verify this by using a telescoping mirror and looking behind / around your valve covers for leaks around the tensioner, cam journal, and cam caps. When the engine is cool, you may even be able to stick your hand back there and feel oil.

A vacuum leak sounds like it could be the issue for your rough idle / acceleration issues. You can spray your vacuum tubing with starter fluid and listen for your engine idle speed to change. When / if that happens you know your vacuum system has a leak and it needs to be addressed.

 

Thanks N!!!!

Actually that's good news believe it or not. We are in the middle of the cam seal/valve gasket job so that means we are on the right track.

One follow up....I have had no coil issues but someone recommended replacing them while doing the cam seal / valve gasket job.

I have had no issues with the coils so to me this doesn't make sense.

What do you think.

 

There is an active recall on your coil pack. If you haven't visited a dealer in a while, you may want to call your local Audi dealer and see if you're included in the recall. You probably are.

What's the likelihood of it being coils causing your issues? Probably not very likely given you're not seeing a CEL. Still a remote possibility, but not certain.

Once you get it all back together, your best bet would be to go the starter fluid route and spray down your vacuum hoses to see if the idle speed changes. Chances are you're seeing a small leak.

Also, don't forget to change your cam caps while it's open. The driver's side cam cap is notorious for leaking very badly and will drip right onto your exhaust causing it to smoke like crazy when it gets bad.

 

Thanks again Nebuchadnezzar!!!!