I need your help. My 2007 GT3 is a daily driver, has not been tracked or abused in any way. Never over revved. The only mod are a GCG Sport Center Section exhaust.

Several month ago the engine developed a vibration over a very narrow band: 1500-1800 rpm. It's not misfiring, just feels 'lawnmower rough'. Enough to induce a body resonance to the point where door panels vibrate. This phenomenon occurs while accelerating, decelerating as well as while the vehicle is stationary; clutch in or out.

The car has been in at the Porsche dealer for two weeks now. They've checked compression, run a leak down test, replaced motor mounts, spark plugs and coils, and checked the accessories belt. They've re-installed the factory muffler. The vibration persists. All diagnostic codes are within parameters.

Today the service manager informs me that Porsche asked him to drive the car twenty miles to "warm up gel in the flywheel" in case that caused an unbalanced condition. WTF!??

The shop hinted that the next step would be pulling the motor and checking the flywheel, clutch and pressure plate.

Any help at all by the collective resources/brainpower of the 6speed community would be most welcome! Thanks in advance.

 

I have a LWFW and get a unique sound between 1500-2000 RPM in my C2S, I would think that the dealer looking at the FW could be on the right path.

 

you might ask them why they have to drop the motor to check the flywheel...is it really easier (less labor) than dropping the transaxle?

 

U got a cage in there? The added stiffness can translate to unwanted nvh. flywhhel is a good start- u got the stock dual mass or lwf? Purchased new or used? If used maybe lwf installed by prev owner. Mike

 

Have them check the front belt pulley they have reported to come off although normally without a warning but have them check to to eliminate a future problem. Good luck, the good news is, its on there dime.

 

Good News! Thanks for all the replies/suggestions. Picked the car up today and the engine roughness has disappeared! Although the dealer checked the motor mounts (they're hydraulic I was told), Porsche recommended that they be replaced. That seemed to solve the problem.
I'm so very happy to have the P car back - was driving a WV Passat for two weeks. Aaargh. Life is Good