Hello. Long time lurker, first time poster. I bought my new 2011 A4 S-Line in April 2011. My car has been flawless, up until a few weeks ago. I went outside to my car this morning, got in and attempted to start it. When I pushed my key in, my car started but began to idle very rough. The RPM bounced from 500 to 1000RPM and the engine light was on. It sounded to me like the engine was misfiring. I turned the car off after about 10 seconds as it wasn't correcting itself. I waited 30 seconds and started the car again, and it ran fine. No engine light on.

This has happened 3 times in the last month. I have a service appointment booked.

Anyone having similar issues, or any ideas what is wrong? I know it is under warranty and I will get whatever is wrong fixed, but my issue is that it doesn't happen every time. I'm worried when it goes in for service, it won't act up, thus go undiagnosed.

Thanks,

 

You have little to worry about. Worry is just interest on problems you don't have yet.

In order to throw a check engine light the computer has to know an offending system has a problem. It will record a code that the dealer will read the code(s) and take necessary action. Even if you have contminated gas a code will show.

Good Luck!

 

I had this problem a few months ago. But it didn't happen on cold start.

I have a MY2011 B8 A4 2.0T petrol S-line.

While driving one day it misfired heavily and eventually the engine light comes on - solid. It settled down after 10 seconds and the engine light went away. This happened 2 or 3 times each time the engine light is on solid until I just get home and it starts misfiring and the engine light starts flashing and I shut it off and organise a tow to Audi.

When the tow truck driver picks it up the car is running fine. When Audi check it they cannot find anything wrong except for one of the spark plugs being heavily covered with oil. They clean it up and everything is fine for 2 weeks before I have to take it back to Audi because it is misfiring again.

Again they find the same spark plug covered in oil. Coil packs were fine.

When I dropped off the car I insisted that they conduct an oil consumption test as I had added more than 4 litres of engine oil in 8,000kms since new. It also would spray soot all over the driveway from the exhaust each time I started the car.

They told me that they couldn't conduct an oil consumption test before 15,000kms but eventually got the go ahead from Audi Australia because it might have something to do with my oily spark plug issues.

Oil consumption test resulted in oil loss of ~1 litre every 800 kms!(my estimation) which is more than double the 0.5 litres every 1,000kms stated in the manual. I literally had the low engine oil light come on every 1.5 weeks for 6 weeks during the test. So it failed the test and now I'm waiting for new modified pistons, new breather valve and software upgrade to arrive so they can be fitted to my car - covered by warranty of course.

Funny thing is that I never had any misfiring issues during the oil consumption test and the engine oil consumption rate went up as well.

My advice is get an oil consumption test if they find your spark plug/s covered in oil.

 

Sounds like a blown intake manifold to me. I've already had mine replaced twice and when it goes it idles like crap because the A/F ratio is out of whack.