A6Louie

Hi all,

So this issue has been going on for about a year now. In warm weather months, my 2012 A4 Avant sometimes doesn't start. It turns over but doesn't start. My dealer has looked at it a number of times and has made replaced various components thinking that it might solve the issue, but it hasn't.

I've read in a few places that people had this issue when the coolant temp sensor got stuck thinking the car was "hot" and that somehow caused the car not to get enough gas when starting and what I've been experiencing would happen.

(note that when this happens, if I push the button, then hit the gas when the car is turning over, it'll start...it just won't start on its own when this happens without me doing that)

My dealer's tech said that the coolant temp sensor issue was a known issue on older model years, but doesn't apply to newer model year A4 cars, including the 2012 models. The car is out of warranty so I don't think he was just trying to avoid servicing the car (in fact, they've been very generous with their time on this issue).

Anybody else ever experience this and might know what it is?

Thanks in advance,

L

johnc_22

It just happened again - no start. On the second try I pumped the gas and it fired up almost immediately. It's a clue, anyway.

A6Louie

Has anybody else here tried to replace the Coolant Temp Sensor to see if that fixes it?

slonela

I would love to know as well what other have tried. 2010 A4 issue is when engine is up to temperature, and I am trying to start it up again. So I do not have any issue on cold start, when temp. is hot.

jim_e

same problem, 2010, only when its warm, giving it gas will start it. thanks for letting us know, having the dealer try things to fix it is eye watering, hopefully someone will find root cause and reply.

Rsniper4

Might be related to a canister purge or vapor valve issue. Does your car have difficulty starting after refueling? If so your purge valve might be malfunctioning.
Similarly, a faulty vapor valve allows gasoline vapors to flood the combustion chambers, displacing the air and thus preventing combustion. Under throttle air returns back into the cylinders and normal combustion is achieved.
Hope this helps

AndreX86

I'm having the same issue with a 2013 Audi A4 Allroad I bought used a few months ago. It had about 74K when I bought it. I've replaced the camshaft and crankshaft sensor but the issue is the same. I'll likely be replacing the vapor valve soon and will try to update.

AndreX86

I have a 2013 Allroad with the same/similar issue. It looks like it was the PCV valve in my case. Replaced it and didn't experience the issue after a few fill ups. Car also starts better. This appears to be a common failure. Part# 06H-103-495-AK . If the issue returns I'll update the post but I think its done at this point.

AndreX86

Unfortunately the startup issue came back a little while after replacing PCV Valve. But what is weird is it came back while it was cooler outside and now thats it has warmed up and after replacing all the E85 with 91 the car hasn't stalled since but it is hesitating just a bit on startup sometimes and I can't tell if it's normal or not. So I need to play the waiting game some more and see what happens.

I believe replacing the PCV valve resolved oil consumption issues. After replacing the oil I haven't noticed it going down at all and before it seemed to consume it fairly quick. It may have also helped with the initial starting issue in some way but I can't be sure.

One thing to note is I bought the car used and found out that the original car battery is still inside... So it's 8 years old at this point, straight from the factory. so I need to get this replaced asap just to eliminate any possibility of it being a dying battery. If it doesn't have issues for the next month or so then it likely was the PCV valve and those start up issues where ghosts??

AndreX86

Replaced the high pressure fuel pump and the issue is resolved. Not even a hint of hesitation after driving around for days in extreme heat.