Earlier this year, my spark plugs and casings were replaced by the local Porsche Dealer. Defective coils like these were replaced with new ones by them.

Now it looks like a similar problem - but did not even make it out from the garage - last time it was lost of power, etc.

Car would start and 30 seconds or so later it would completely dies ... even after trickle charging the battery overnight ... I pulled the fuse of the Ignition (fuse #41) and plug the fuse back in - same problem ...

Any ideas??????????????? Alternator? Car's battery? Coils again? Doing too much short trips (in and out 5 minutes twice a week and very few longer trips)?
Fuel pump? Short circuit somewhere? Computer issues?



HELP!!!!!!!!!!

 

Search the Fuel pump thread on here. There are two, you can pull the fuse for one and trick the other one into operating and see if it runs, then try vice-versa if it doesn't.

 

Will look for the fuses since I have the cover open now ...

So there are two fuel pumps? And it is a known issue for 04' CS, etc.?

 

yes, may be one or both

 

But is it a known issue or even a technical service bulletin. If so, I should send it back to the dealer?

 

its not a service action item, but they do wear out. At the dealer it was $800 ish to replace 1, so if you are out of any warranty and capable then diy or indy is the way to go

 

I took out fuse 14 and it does not die. Take out fuse 13 and it dies in 30 seconds.

Can I still operate the vehicle / take it to a repair shop with one fuel pump???

 

Yes, just don't go full throttle, or you potentially risk under-fueling.

 

I have driven now about 1200 miles with my fuse pulled. I'm going to replace the fuel pump (actually both since labor is the same) soon though.

 

My mechanic is coming tonight to check it ... but do both of them tend to fail or just one of them would fail and the other would remain operating well over years of use?

 

I suspect there is no way to accurately answer that question, each pump would be different. How lucky do you feel? I think I would have both of them replaced myself.

 

My indy recommended to do both just because labor is the same and that way there is no risk of the second one failing and eating the labor a second time.

 

That make sense - doing both - as my mechanic only have to craw below once for the change. Before I checked the fuse as per the discussions here, he actually heard (from crawling under the car) that the fuel pump(s) were noisy.

I live on a hill so may be it is not a good idea to drive with one pump - that is, going uphill will require me to press on the throttle a little - even with the horsepower of this car.

 

Just so you know.. You access the fuel pumps under the rear passenger seats. There are little access holes under the carpet. Not from under the car in this case.

 

I have a quote here parts alone - both pumps - totaling about $700 plus $100 for the fuel filter. Is that good for genuine Porsche parts but more importantly are these new pumps going to fail again as quickly as the old one??

My Cayenne S only has 45,000km (about 28,000 miles) on it .....