i have a 2008 A4 Quattro 2.0t six speed. I was driving it with no issues. Shut car off went to go start it later and it wouldn't start. Made no noises when I turned the key. However. It would start when you roll start it. I roll started it and drove 40 miles or so and my battery light came on. Couple minutes after that all the dash lights went out. Then a couple more minutes and the headlights went out. Pulled off the road and the car idled for 20 minutes and 3 lights came on the dash. The ABS,airbag, and the traction control. Also when lights went out the car started to act like it was going to stall.

 

Symptoms sound like it could be your alternator. They often fail slowly causing all sorts of weird electrical issues. These cars are especially sensitive to electrical system problems and do strange things when they're not getting the required power. I would start there. Any local auto part shop should be able to test it. Or, if you're super handy, you can just pull it and swap it out.

 

thanks! Also. I recently had to do an engine swap because the other one blew on me. The engine light was on before it blew up. They put the new motor in and it was still on. Code was for the cooling performance system. I read up on it and they said it could either be the thermostat or the sensor. Have any ideas?

 

P2181? Probably the thermostat. Too bad they didn't put a new one in while the engine was out, it's a bit of a pain to get to on the B7s. Sort of odd that they could replace the engine and you'd still have an issue with that.

 

May be a dumb question, but did they clear the code after putting the new engine in? if not that code very well may not be valid anymore.

 

They ended up replacing the thermostat and said that it was fixed. Mechanic also put a new starter and clutch safety switch