Duplicate post

 

The only time this happened to me was the result of a cross threaded plug. I wasn't a Porsche but the plug opening had to be re-threaded/tapped.

 

Is there an ECU update that is supposed to be performed at the 60k? I'm not aware of anything that was done with the PIWIS other than coding a new key for me and taking some readings. Plus they crawled through the computer data as part of the PPI.

 

Hmmm...I don't think I want to put 3000km on it in hope it resolves itself. I probably put that on in 1/2 a year.

 

I don't think there's an ECU are flash at 60k miles. I am at 66k miles, serviced by me, and my car still idles fine.

Why don't you call the shop who did your service and ask them just to ensure.

So the reset, Techron, tightening the gas & oil caps and new gas haven't fixed anything?

 

Its going to go back in for the shop to have a look at it for a day or two. Maybe a plug that's gapped incorrectly, or a slightly faulty coil.

 

Good luck on your search bro. Do inform us if the dealer or you find the cause....

 

Ask the shop to check which plug manufacturer they used. My local shop recommended using NGK instead of Bosch due to quality issues.

 

Good tip. Will do. Thanks!

 

Well, the shop was unable to find diagnose any problems. They tried to get it to misfire and it wouldn't. They looked at all the data using PIWIS and nothing was abnormal there.

Now I wonder if I should take it to the dealer to check out, but they would most likely perform the same tests using the same equipment.

I don't know if its my imagination or not, but the problem seems like its getting a tiny bit better, and quite frankly, its not a horrible thing, but is sure seems like it should idle smoother without vibrating my seat. It will probably get worse in the cooler weather at a lower idel speed due to AC being off.

Doe anyone know of a TSB that might be related? Should I take it to the dealer to get a second opinion, or just let it go and enjoy the car?

Also, the previous owner had done some performance mods to the car and my shop noticed is was a really fast car when test driving it. Is there a way to determine if the car has been chipped without looking in the ECU?

 

Have you try a bottle of Techron?

I recall at lesat one thread, here or on the other site, where somebody fixed a rough idle with Techron.

 

Could be water in you gas. This happens a lot with gas stations that have car washes. A bottle of Heet will fix this issue and it's only $1 or so.

 

Well, nothing to lose by trying the Techron.

Still, it seems the problems stared when the coils and plugs were changed, so i'm not optimisitic.

On the water comment, I use pretty much rhe same station which has exxon gas and no car wash. If it was water related, wouldn't that effect more than a slightly rough idle?

 

Just sharing my experience with bad gas. My car had a rough idle when I pulled to a light and even stalled. Called my local PCar tech and he said it sounded like water in the gas. He put a bottle of HEET (which removes water) in the tank and the problem went away.

 

I had a similar symptom that was also causing cylinder misfire codes to pop up. I ended up replacing the following sensors which eliminated the tach needle wobble and the misfire issue.

Sensors Replaced at 78k miles
1 x Crank position sensor (replaced by my indy)
2 x Cam position sensors
2 x Actuator Valve (Note there is a VIN split in the 2005 Carrera S, there are 2 part numbers)
2 x Actuator Camshaft

I would also recommend replacing the Lid actuator which bolts over each sensor and has a rubber o-ring seal. You'll need a total of four, two for each actuator type. If you've done your own coil packs and plugs you can replace any of these parts.

After replacing these sensors I also noticed the car pulled more consistently in the higher RPM range.