MHaas42

The engine light on my 2009 Porsche Cayenne 6 cyl. with 105K has been coming on lately and it is has had some idling issues. After a 3 hour highway drive, at the next stoplight it revved from 1,100 to 1,500 repeatedly as if I was pushing on the gas every second or so. Other times it just idles rough but runs good otherwise. I reset the light a couple of days ago and it came back on this morning (cold here in Birmingham, AL - 10 degrees - does seem to be worse in the cold). There were 7 codes (some were duplicates).

1.) P0507 - Idle Air Control - RPM Higher than Expected
2.) P2187 - System Too Lean at Idle Bank 1
3.) P12A2 - Manufacturer Control
4.) Repeat of #1
5.) Repeat of #1
6.) Repeat of #1
7.) C342D - Manufacturer Control

This is my first Cayenne. I have had it for just over a year and put 15K or so on it. It has been very reliable and not expensive to maintain so far when compared to a few BMW's I've had over the years. I'm relatively handy (did the brakes a while back) but am not nearly as capable as most of you on this forum. Any tips before I take it to my local shop? Thanks in advance for your help!

nodoors

I am not familiar with the VR6 and its codes, but cleaning the MAF and checking for vacuum leaks in the intake would be the first two things I would do based on what you have described.

MHaas42

Ok, I just searched this forum and found a lot of references to cleaning the MAF, but no "how to" info. Is there a place I could find some instructions for how to locate this part and clean it properly? I tried the normally reliable Youtube and struck out there also.... I appreciate the input.

PTEC

Oil separator is faulty, its built into the valve cover. Another guy on here did one himself a while back but its a pretty challenging job even for a professional mechanic.

pchak

Agree with PTEC. This is likely. I had same issue. The problem is, you need a p-car shop with a PIWIS to do it.
I was able to get all the parts on-line, which were fairly cheap. The valve cover is only a couple hundred bucks, but there's a Russian company on eBay that sells the diaphragm for less than $20, and you can use your existing VC. The gaskets for the intake manifold and VC are under 20 bucks as well. I was going to do it myself, but did not have the time to do it myself, and it would have been to the limits of my ability. My local independent guy (not Porsche) did the work-really easy for one of his guys, and he charged me $250. However, the car runs really rough, takes 10 minutes to get running, and it was either here or another forum that the direct injection V6 has 5 (?) settings that can only be manipulated via PIWIS (not Durametric or comparable). The "old way" of setting/learning the idle/eGas by turning the ignition key does NOT work.

MHaas42

I did some additional research last night and ended up buying the cleaner and cleaning the MAF sensor last night. The engine light stayed off on my way home from work last night and halfway to work this morning, then came back on. No improvement in the idle issues but an easy one to check off the list before I move on. The oil separator sounds like the possible culprit, but I'd like to rule out a vacuum leak before I move on. Any tips on how best to determine if I have a vacuum leak? Appreciate the input.

pchak

My mech did a check of the vac lines on mine as well (I assume he used a gauge, as well as the soapy water method). We were hoping for a simple solution, but you should see the picture of the diaphragm when it's removed (there are pics in a post somewhere here). You'd understand why there's a big sucking sound under the hood. :-/

Petza914

Best way to detect a vacuum leak is to smoke test the intake. It's a machine that you hook up to the air intake and it pumps harmless low-pressure smoke up through the entire intake tract and if you can see any escaping, that's the source of a vacuum leak. Since these things can be really hard to detect, I actually bought one of these machines for my home workshop. A good indy should have one.