Check engine light and rough engine, help?

**PistolPete13** · #1 (**permalink**) 12-09-2007, 03:26 PM

Hi everyone,

Due to the bad weather here, I had to leave the car sitting idle for the last 9 days on 1/2 a tank. I know, that's bad. It was in the driveway and temps reached 20 degrees F a few nights.

So anyway, early this morning I took it out for a quick warm up drive. 10 miles in, the check engine light flashed along with the exclaimation point. It flashed for a few minutes and stayed on steady. I was on the highway and immediately got off to turn around.

I noticed the engine running really rough and could feel it especially in 2nd gear. As thoughts of a tow truck call early Sunday AM flashed in my head, I saw a gas station, pulled in and filled the tank. It took about 8 gallons.

Once filled, I started the car to move it away from the pump and park it. The check engine light didn't come back and the car was running smoothly again. I made it the 25 miles back home without any more issues even after a few restarts.

Any ideas? Condesation water in the tank? Is it that picky? My dealer is 30 miles away and I think I'll take it in tomorrow. Hopefully whatever happened was stored and they can read the code. The car has 700 miles.

Ugh, I'm going to be worried the rest of the day.

**SY987CS** · #2 (**permalink**) 12-09-2007, 03:40 PM

I think that you may have cleared the light when you shut off the motor and restarted. Adding fuel probably didn't fix the problem. Remember, these cars sit on dealer lots for months with very little fuel in them. I can't imagine that nine days with 1/2 tank would cause a problem to a car without other problems.

**fmarshall** · #3 (**permalink**) 12-09-2007, 04:19 PM

The could have been some connection that was effected by the cold that caused the light to come on. Then after it got warmer it wasn't an issue. You should be able to run by the dealer and have them check it. They will know why it came on.

My other guess is that it could have been because of the cats. They can be effected by moisture or lack of driving when the car is fairly new. I had a similar problem with my car, that went away.

More driving = less problems.

**EJPhoto** · #4 (**permalink**) 12-10-2007, 02:40 AM

I was out of the country for two weeks my car had about 500 miles on it and it did the same thing. Shutting the engine off and restarting it cleared it. It is due to moisture in the cats at initial startup which vaporizes very quickly once the engine is running but the engine needs to be restarted to clear the light.

I didn't have a rough running engine though - are you sure that was real or did your senses tell you that because you had the warning light on?

zamalek · #5 (**permalink**) 12-10-2007, 02:59 AM

pete, i'm in staten island & i drove my 2.7 every single one of those days, i put on contis winter contacts & the car is amazing on winter roads, even a couple of inches you can drive in, the stability & the traction controls are awsome, i had a simmilar problem but without the light, the engine would tick loud for quite a while till the oil warms up, then it would run smoother, my problem is my dealer is new country in greenwich, some drive, but at the last service i had it checked & they said it was normal, just watch the oil level, cause mine was low, they added to fill, it kind of ran better, enjoy, beautiful car, mine is also mg.
ralph.

**K-Man S** · #6 (**permalink**) 12-10-2007, 03:03 AM

Always a good idea to invest in an inexpensive code reader so you know what fault code has been tripped.

JamieD · #7 (**permalink**) 12-10-2007, 03:40 AM

... find an inexpensive code reader- what brand and what do you define as inexpensive?

**K-Man S** · #8 (**permalink**) 12-10-2007, 04:06 AM

I bought an Innova one at Sears for $49.95 or maybe it was $59.95, they had several ranging in price from $30 to $200. The one I bought reads and clears codes which is all I really needed.

**PistolPete13** · #9 (**permalink**) 12-10-2007, 04:06 AM

Thanks for all the suggestions everyone. The car was definitely running rough for a bit, had to give it more gas in 2nd gear pulling into the gas station, sounded and felt like it was going to stall.

Oh well, I had the day off tomorrow anyway, so off to the dealer I go. Hopefully it won't act up on me during the trip.

The Durametric software looks more tempting by the day. Or I can go for one of those generic readers at Sears/Autozone, etc.

Keeping my fingers crossed tomorrow. Arggh, the car is no longer perfect!

**PistolPete13** · #10 (**permalink**) 12-10-2007, 04:08 AM

Dumb question, but I guess those readers will read a pre-defined set of generic codes? Or do we find to find a lookup table for Porsche specific codes?

skup · #11 (**permalink**) 12-10-2007, 04:13 AM

I do not think you have any problem. I had a check engine light come on once and it also cleared itself by restarting the car.