997.1s idle vibration when warmed up?

[ragnarok]

 Hi,  I have an 2005 997.1s which seems to vibrate a lot durring idle. 

 

The rpms appear stable around 720rpm, and while not spin cycle bad,  it does feel like I have a blender bolted to the seat rails. 

 

With the car stopped and in neutral,  if I step on the gas and hold it to 900 rpm,  it becomes very smooth.

 

I have a durametric and I am not seeing any codes at the moment. 

 

 Any suggestions on what this might be or things I can do to narrow this down further? 

 

Thanks so much! 

[Ahsai]

How are your engine mounts?

[ragnarok]

Thanks AhSai, I'll check tonight - is there a way to see from under the car? or they must be removed? I know that my exhausts on left/right side are even, but that could mean they both failed. 

[Ahsai]

You can kind of see it from under the car.

 

https://www.specr53.com/blog/diy/porsche-996-motor-mount-replacement-diy/

[Ahsai]

You can plot the "Rough running cylinder #1, #2,..." (in 1/s^2) at idle and that will indicate how smooth/rough the engine is.

Also, plot the misfire counts in Durametric at idle to see if there's any misfire.

[ragnarok]

Thanks Ahsai! - I didn't get a chance to hook up a durametric to it yet, but I did inspect the engine mounts as advised- they are both definitely done-  the rubber part protrudes somewhere between 1/2 inch and 3/4 inch. I'll be ordering a new pair- and when they get here will see how much things will improve! 

 

Thanks again!

[ragnarok]

Just wanted to update this thread,  replacing the engine mounts did the trick,  the idle vibration is no longer bone rattling. 

 

Thanks again Ahsai!

[Loren]