tom

My car started this morning, about 29º outside and began idling very roughly. The check engine light started to blink, and then stayed on. The dealer said it should go off in a day or so.

Any thoughts?

CraigB

...when I hadn't driven it for 2-3 weeks. It stumbled when I was starting it and the check light came on. It went off after a couple of days with no ill effects.

CraigB

HP

Was home in Burlington, VT for the holidays and some nights the temp. hit -10 degrees F. One morning after a particularly cold night my car behaved exactly as you describe. Very rough idling(obvious cylinder misfiring) with the flashing check engine light. I quickly recycled the engine again and still noticed the rough idle and check engine light. Finally, after letting the car sit for about 10 minutes with engine off, I restarted and the rough idle was gone. The check engine light remained on, however.

A quick call to my dealer's service dept. revealed that this is relatively common with the A4. As long as the rough idle doesn't come back, the check engine light will go off in a day or two and all is good. Haven't seen the rough idle since.

My theory is that a small amount of water may have gotten into my gas tank through condensation in the summer months. On such a cold night, the water froze and blocked my gas line resulting in cylinder misfires.

99.5 TQMS w/ 1.0 bar APR (ver 3 in the mail now!)

Brad Bilut

Sounds like you were getting misfires

zain

Misfires. Mine had a bad spark-plug wire. Have dealer read the DTC code before light goes out.

Darren Lee

It happened to me a month ago when temperature was close to zero. Dealer said engine misfire. They took the car, clean it, replaced spark and spark-plug wire.

Take it to the dealer!

Jake

Sounds to me like a 2.8 that's carboned up. If so the dealer should: Install a hotter 92°c thermostat, special, hotter spark plugs (retail $28 each), decarbon the valves and change the oil. Covered uner 3/50 warranty. Don't let anyone tell you tha light will go out in a few days (that's not a fix). Get it fixed. If not, the next step is no start. Call a tow truck. Your choice.

Jake