GDJT Allroad^2

Howdy!

The last time it got really cold, a month or so ago, a night similar to tonight, my '97 A8Q ran rough and the check engine light came on. After shutting the car down and restarting it would run fine but the orange light still glowed. After that incident it ran fine, and 24 hours later the check engine light dissapeared. Tonight was also chilly, and since tonight was the second night this occurred, I fired up VAG-COM and pulled some codes...

16705-P0321 Ign./Distributor Eng.Speed Inp.Circ Range/Performance
18020-P1619 Electronic Control Module Incorrect Coding
17915-P1507 Idle Sys.Learned Value Lower Limit Attained
16884-P0300 Random/Multiple Cylinder Misfire Detected
16692-P0308 Cyl.8 Misfire Detected

... the last two were repeated.

So where do I look? Ignition control module? Plugs and wires for cylinder 8? Coil packs (Does the A8 even HAVE coil packs?)

Terrybill

My 97 does the same thing when it's cold soaked. I read somewhere (probably here) that it has to do with the fuel cap seal. I never bothered to pull the codes when it happened. The car ran fine and the light took care of itself after a few cycles (days). My kind of maintenance although a preferable alternative might to get the heck out of Minnesota in the winter.

If you've cleared the codes lately and those have found their way back, best of luck to ya ;-)

Mitaka

I had a misfire too when it got cold a couple of months ago. Dealer performed DECARB of the engine. It has been running fine since. I am keeping my fingers crossed.

GDJT Allroad^2

About a month and a half ago, when it first got cold this occured. After restarting the car it ran smoothly, and about 24 hours later the check engine light went off.

Then tonight it happened again, so I pulled and later cleared the codes. The light didn't come back on during the ride home (had to use a computer in my in-laws garage since I don't have a warm garage.)

If this is common when cold, I'm not too worried. I'll check audipages and other places for the fuel cap info...

Egil A64.2s - S6

plug and it was fine after that. Good luck.

Excellr-A8

My car has also done this since last year. Whenever the temp gets below about 15 degrees the car misfires at startup. If I let it warm up for about a minute or two then it runs fine. The codes are a random misfire and #8 cylynder misfire.

I am suspecting a bad coolant temperture sensor but haven't had time to confirm. I think the computer is getting the wrong temperture reading and is leaning the engine out.

It is going to be down in the teens today so I will see if the problem happens today.

Jeff B

escapA8

https://forums.audiworld.com/a8/msgs/46399.phtml

https://forums.audiworld.com/a8/msgs/46927.phtml<ul><li><a href="https://forums.audiworld.com/a8/msgs/46239.phtml">https://forums.audiworld.com/a8/msgs/46239.phtml</a</li></ul>

BigThistle

Try a bottle of Redline SI Fuel System Cleaner in your next tank of gas