Al.Fresco

Porsche Sports Exhaust.

Roadster Jay

Thanks: This is an engine related vibration that I believe has nothing to do with exhaust systems. I believe it occurs at variocam transition. From what I gather there must be quite a bit of variation from car to car. Interesting that my neighbor had 2 cars in a row with it, I have it, and 991Carreradriver had it on both of his cars. It can be felt on a fully warm car in neutral at 3250 - 3300RPM. I'll continue to share whatever I learn on this.

kayjh

Is this present in 991.2 engines?

Roadster Jay

Good question: I wonder the same thing. I would believe the answer would be yes as the basic design and variocam should be very similar.

991carreradriver

I am not so sure it is related to the variocam. I think folks are confusing the stumble issue at 2600 RPM that has been linked to the variocam. As far as I know and I have been following this for three years, there has been no official explanation for the engine vibration sound at 3250rpm beyond harmonic imbalance. It is possible that a soundless engine vibration is causing other parts to sing out. For example, one owner placed a clamp on a heat shield and the sound changed. This issue throws no fault codes and PCNA has repeatedly said its normal via its dealer network.

Needsdecaf

I tried it out this weekend. Deliberately hung out in the 3k to 4K rev range.

No vibrations.

pfan

I'd gladly trade my 2600 rpm stumble for a 3200 rpm vibration.

991carreradriver

As you are all too keenly aware, these are different problems. The stumble is a real PIA. The 3250 metallic vibration is a minor nuisance. It has no lasting negative effect and is not that pronounced to anyone except those that are listening for it. As I have said before, this issue is not a big deal, the stumble on the other hand is not good. There is no excuse for it and PCNA has dropped the ball and is hoping the problem just goes away. If I was so afflicted, you could bet that I would not put up with it. I would document, document and document, then I would make them buy the car back. Its probably too late now as they seem to have corrected it on late model 991's as no one seem to be complaining about it. I guarantee this is all related to PCNA meeting emission targets.

Some folks have had great results after having their car tuned, others by changing out the throttle body (IPD Plenum). In any event, good luck.

vivalaReagan

awww c'mon, guys! it's so simple, maybe you need a refresher course. it's all ball bearings nowadays.

if you want to really fix the vibration, you'll need to prepare that fetzer valve with some 3-in-1 oil and some gauze pads, and you'll need about ten quarts of antifreeze, preferably prestone. no, no make that quaker state.

pfan

That would explain why Porsche absolutely refuses to look into the problem. Could it be they have something to hide????

Hurricane

Needsdecaf

These mattresses have no tags....