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,

 

No idea what the issue is, but I also got my A4 in April and I've noticed on cold start my engine typically idles slightly over 1k RPM for about a minute and the fuel consumption will show that its using around 4 liters per hour before it drops down to normal at around 7-800 RPM and 0.9 l/hour. Maybe a warm up process that wasn't working with your engine that it kept trying to do but couldn't?

 

I also have a 2011 A4 S-Line that I picked up at the end of May and it sometimes does exactly that. If the engine is not warmed up when it is started the engine idles like asmallrabbit describes but sometimes it gets rough and the rpms oscillate like you say with the engine light on. It has happened about 4 times so far and the first time I turned it off and back on and it was fine. The next time I just gave it a little gas to help it get over the 1000 rpm threshold and it started idling fine and the engine light went off. So that is what I do whenever it happens.

Still going to have the dealership check it out though but I am in the first love phase and can't let it go yet

 

I would be very interested in what the dealership had to say.
I've had this happen to me twice now where there is extremely rough idle and the engine light comes. The first time the engine stalled and the second time I shut it off.

 

The issue is caused by engine control module software and the range of crankcase vacuum allowed. The repair includes replacing the crankcase breather valve with an updated part that allows for more vacuum, replacing the front crankshaft seal with an updated part capable of handling the increased pressure, and a software update.

This is what the dealer told me. I guess the issue has been identified in other vehicles, thus being able to be diagnosed. Haven't done the repairs yet, had to wait for some parts to arrive. The dealer assured me there is no danger to keep driving the way it is.

Good luck.

 

I'm having the same issue with my 2009 A4, but Dealer says there's no known solution and my warranty is expiring relatively soon (72km out of 80km)...

Were your repairs completed? Did it solve the issue?

Can anyone suggest what I should do?


Thanks!

 

My car had a software update and a breather valve + seal replaced.
I've had no problems since.

 

Is there anyway you could scan your workorder for me..? just so I have something to show them when I go back in...

Thanks!

 

see attachment

 

thanks! will report back once I talk to dealer.