GDA4

Anybody ever have this problem or know what it might be:
I start my car a few weeks ago. There was less than a 1/4 tank of gas. The car idled rough for a few seconds, the check engine light went on and the idle stabilized. I get gas, turn the car on and the check engine light went out. I was doing good up until yesterday. I was driving home from work. I was stuck in light traffic and the check engine light went on again. No rough idling, nothing out of the ordinary. Full tank of gas.
This ever happen to anyone????

up2nogood

I just had a very similar problem with my 99.5 2.8QMS last week. It started it one morning and it idled roughly and seemed a bit sluggish (thought the emergency brake was still on a little) pulling out of the garage. I noticed the check engine light was on. By the time I got to work it was a little bit better but still not the same with acceleration. I drove it to the dealership and they said that I had a bad fuel injector which caused the engine to misfire and turned the light on. They said that tons of things including bad gas can cause the engine to misfire or for the check engine light to come on. Sometimes the problem will go away and the light will go off, other times the light needs reset. (And there are those few times where it's a more serious problem.) Good luck with it.

GDA4

Thanks. I might give it a bottle a fuel injector cleaner. If that fails then i will go to the dealer

dB

A goofy coolant sensor could cause cause the ecu to think something different, which "may" cause a rough idle due to incorrect mixture.

ReyHey

new Coolant sensor, problem solved.

JWG

I have battled random, intermittant, unidentified misfires at idle; your situation does not sound like a fuel injector, especially since your car remains new. Leaky/clogged fuel injectors do not get better without passive or active cleaning.

Next time it happens have someone pull the codes with a VAG-com to figure out what the computer believes caused the problem.

Consider this your starting point and proceed (rationally) from there.

With a 1.8T's coil-on-plug design, you should not have too many problems with ignition unless your plugs go bad; the 2.8's have plug wires which add another variable to the possible problems.

I think you may have a sensor problem, if the check engine light came on for no apparent reason. Computer will react the same to bad info as it reacts to correct info about a problem.