dimitracos

Hello,

I have a 2.9TT Cayenne S with PDCC and air suspension.

Please advise where to look: on a warm car, when I release the throttle (only in the RPM range of 700-1000) at speeds of 20-40 km/h, I hear a rattle from under the hood for a couple of seconds. The sounds seem to be coming from near the engine compartment partition. If I give it some gas, the rattle disappears immediately.

There is no such issue on a cold engine, and there is no problem at higher speeds. There are no error codes. The acceleration is excellent. The issue occurs both with and without the air conditioning on.

Checked all the protective covers - they're not loose, and we've also checked the drain plug cover. The dealer only noticed a slight play in the wastegate shaft but isn't sure if that's the cause

chassis

What year and how many kms on this vehicle?

30kmh/19mph in 3rd gear, correct? This is one of the speed/rpm ranges where the driveline vibration/rumble is present.

However, the sound in the video sounds like a rattle, not a rumble. Do you feel the vibration in the seat or floor?

If it is a rattle, it sounds like a loose heat shield. An inspection under the car to check the several heat shields is the way to see if that is the issue.

dimitracos

Thx for reply!

I do not feel any vibration, most likely it should be something like heatshield, but it is pretty strange that sound appears only at those rpms.
Delaer yesterday checked most of possible issues and also tried heatshield. But we will give another try, thx!

Ericson38

In one case it was the counterbalancer shaft assy (bearings/tension gear assy). This shaft also performs the intermediate shaft role to drive the cam chains for both heads.

The attachment from Porsche shows where to put a stethoscope to differentiate the HPFP from the timing wheel assy.

Check out this thread and play the two videos they posted on the Audi V6 (same engine) Panamera-
18 Panamera What the heck is that noise! - Rennlist - Porsche Discussion Forums

chassis

The 2.9 is coarse. Anything that can vibrate will vibrate at its resonant frequency. The input vibration frequency from the engine is proportional to engine rpm. Therefore whatever is vibrating has a resonant frequency at the engine rpm at which you are observing it.

dimitracos

car has just 40k miles on it and still on waranty , production year is end of 2017. Till the last service on dealership it was really perfect, so I have nothing against 2,9tt.

Quote:

The input vibration frequency from the engine is proportional to engine rpm

In this case it should rattle at idle rpms , but it happens only on the read.

BTW how americal dealers are treating this cases? They are considered as warranty claims?

chassis

Thanks for providing this information. You might have better success posting in the 958 section, which is applicable to your 2017-build vehicle. This is the 9Y0 section for 2019 and later model years. No worries!

dimitracos

9Y0 in EU were producted starting from 2017 So I posted in right thread

chassis

Good deal, didn't know that.

Ericson38

For some early EA839 engines, there were failures of the roller bearings in the rocker arm pivots. But that has not been posted as a failure in this forum that I know of.

B9 S4 EA839 Series Engine Rocker Arm Failure - AudiWorld Forums

B9 S4 rocker arm issue. - Page 10 (audizine.com)

dimitracos

Thx for advice! Looked videos with described issue - frequency of ticking is couple of times lower than mine

SF_

Did this ever get resolved? I’ve got a similar noise coming from the front passenger side at low speed.

dimitracos

Yes! Heat isolation plate between exhaust and bottom of the car wasn’t installed properly and additionally dealer replaced one of the bushings of the exhaust pipe. Now it perfect

SF_

Mine ended up being a loose top engine mount bolt. Didn’t think those could just loosen on their own, maybe they didn’t tighten it after the service or something (assuming they loosen for access, no idea).

chassis

Did you have spark plugs changed?