Hello All,
I have a real puzzle with my 2004 Cayenne S (100,000 miles).

About 2 months ago the engine light turned on. I took it to the shop and the mecanic found small cracks in the gas cap. He put on a new one and all was good until 2 weeks ago. It light up again. I verified the gas cap again ( 3 clicks) and 2 days later... it turned off. This morning at the SAME place as 2 weeks ago ( same intersection) it turned on. Now I know its not the gas cap as I filled up yesterday and am sure I had 3 clicks
2 ideas:
1/Why does this always happen one day after I fill her up ( Not the same pump)?

2/ I live on the top of a LONG hill and so the car coasts down for 15-20 min. Could it be that the engine light turns on as the engine is not warm enough after 15 min? I actually had this problem with my Mercedes c230 Kompressor.
If not the car is babied and runs like a swiss watch.
Any ideas or thoughts?
Many thanks!!!

 

Gas cap was going to be my first guess when I read the title of the tread.

Was an OEM gas cap used to replace the cracked cap? Just curious...

 

I second the vote on the OEM gas cap. I had a leaky Toy radiator cap and replaced it with a non-OEM one. Then another and then another. Finally I went OEM (to the laughter of my service writer at the dealership) and so far so good.

If not that, then your dealer can do a solid diagnostic to find out what it may be. Frex, it could be anything from injectors to a fuel filter to the emissions system.

 

Yes it was a $28 OEM gas cap. I have total confidence in the mecanic who does only Porsche.

 

another idiot thought. I have a service now light reminder on ( will do oil change next month) this has nothing to do with it?

 

How about where you fill gas and gas cap goes on? The bottle neck or whatever it's called. Maybe some wear from use from years/mileage?

 

A service reminder shouldn't trigger a CEL. Do you have a code reader? If so, then you can pull the codes and see for yourself what is triggering the CEL. There could be some other components in the fuel system that need to be addressed.

One thing that's pretty common for Cayennes when they badly need an oil change is a CEL caused by a faulty cam position sensor. More frequent oil changes seem to help prevent this.

 

I did the oil change 7k ago. Too much?

 

That should be fine.

 

Nothing to do with the fact that car whistles for 5 minutes when cold? Once its warm the noise is gone. I assumed the whistle is just cold and humid belts? Could tha have something to do with the engine light?

 

Air injection pumps will come on at startup when it's cold and make a high-pitched whine sound.

 

so thats normal? thanks!

 

The fuel system is sealed at both ends and the engine end valve can go, the symptoms are different and related to filling up, afterward you have starting problems and roughness then ok.

 

No she starts with no issue at all.Hot or cold

 

Update...like last time the engine light just turned itself off... insane...