I wanted to share some of my experience because many cayenne owners
Dont feel very well with this idle dip problems. Many of you know this strange behaviour when coming to stop light and idle drops down and car even starts shaking.

I changend many parts in the last month which needed to be replaced because of
Age or service reasons.

Coils
Plugs
MAF
Filters

Nothing helped to solve the RPM dip problem.

This week i needed to replace my fuel pumps because one was making noises
Like crazy.

Guess what, the idle drop problem is gone with the new pumps.
Doesnt mean it must be always the reason but in my case
It helped. Completely different feeling now !

 

Thanks for the tip, I have the same problem, I replaced one pump a while back as it died, I'll do the other one and see If that solves it.

 

MY 2006 CS also had a slight rough idle and dealer took care of it via replacing the fuel pump with the upgraded version back in 2011.

 

My 2004 tt needed a throttle body adjustment done after having the coolant pipes replaced. Mechanic said it was a real pain to get right but definitely took care of it.

 

I've got the rough idle since I had my coolant pipes replaced a week ago. I had the fuel pumps and all hoses in the tank replaced a couple of months ago before the pipes, so maybe it is the throttle body adjustment? I will bring it back to my mechanic and see what he says.

 

To clarify ...my CTT had the front coolant pipes replaced by previous owner, truck idled rough from the time i purchased until i had the rear coolant plastic replaced. After my mechanic put it back together he called me needing more time to get it ideling right.
Im thinking your mechanic did the same as the previous owners mechanic did and rushed it out of the shop.

 

Well, for last couple weeks, I have been experiencing idle dip / rough idle at stops.
I am still running the original tank pumps on my 2009 957 GTS at 144k miles.
I would hate to get stranded with A pump failure.

Anyone else experienced, these symptoms, fixed the issue by replacing tank pumps?
Please chime in. Thank you

 

2004 CS: I replaced the fuel pumps and filter around 6 months ago to fix a pump low pressure / rich mixture issue but the idle dip and roughness remained until today. Next is the engine mounts that will be replaced by the end of the month and I really hope that's the fix.
From the many threads I read the consensus seems to be that worn engine mounts are more likely to be the cause.

 

Did you solve the rough idle problem?

 

I’m pretty sure the answer is engine mounts.

 

Okay. I have change the engine mounts and the PDK mount. But I have engine vibrations

 

Replacing the engine mounts did solve the idle dip when coming to a stop, but the rough idle was more related to leaks in the air intake and vacuum system. For those I replaced most of the gaskets and seals plus any damaged hose I found that resulted in a better idle.
There is still a slight roughness but unfortunately I haven't had time to chase it anymore.

Good luck

 

Okay. Thanks. I will check vacuum leaks.