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I recently bought a Cayenne S 4.8 from 2008. After a month the HPFP went down so I repaired that (900 euro), no problem if it is just a standalone incident but it seems to be very common for the 4.8 engines. Mine was already replaced with the former owner in 2010 and 2011.
My engine was replaced in 2010 by Porsche and now this engine has around 100k kms (so the second HPFP failed just after a couple of thousand miles). This made me thinking about the build quality of the Porsche engines. The HPFP is not Porsche made I guess (Continental is written on it) but if "I would be" Porsche, I would look for another manufacturer for these parts. So I already got the impression that they are not as typically German as I thought. Then I got in touch with other Cayenne owners over the internet/facebook etc. And the first 10 owners (with a 4.8 engine) warned me for cylinder scoring because they all had their engine replaced or sold their car because of this problem. I knew the 4.5 had this problem but I remember calling a Porsche dealer a couple of months ago to ask if the 4.8 was better build and they said it didn't have any issues like the 4.5 had with the cylinder walls. So I checked again why my car had a new engine and indeed, also mine had scored cylinder walls at the time.
Some people say it happens because of starting the car in freezing conditions but in Belgium, it doesn't get that cold like in Alaska or Scandinavia. I suspect just a bad build engine or the wrong use of materials for the cylinder walls.
It would be nice to know how common this is on the 4.8. I am very interested in how a car works and why an engine can fail so I would like to know who has or had an Cayenne 4.8 (S, GTS or Turbo) and if you ever encountered this problem.
By Rod Croskery
As a newbie to Porsche mechanicals, every project is an adventure. This time hurry and a lack of information enabled a stupid error. I filled the power steering reservoir (I think) with brake fluid.
While removing a front axle on my '04 S recently I disconnected the right brake line at the calliper. The fluid ran into a pan. All went well until I tried to bleed the brakes upon reassembly.
With my mind on the problem down below, I opened what looked like the brake fluid lid, checked to see that the power bleeder I found under the bench fitted, then dumped in almost a half-litre of brake fluid. Understandably, the pump had no effect upon the bleeding action at the wheels. It was pretty bewildering at the time, though. I vacuumed out the DOT 4 and replaced it with hydraulic fluid from my Kubota, subject to finding a method to drain and purge the power steering system.
One can make all sorts of comments about senility or dumb geezers at this point, but a more profitable approach would be to produce a photo of a Cayenne engine bay, beauty panels removed, and clearly labelled in the manner the best and most helpful of the DIY Tutorials are done on this site. It wouldn't be hard to label the file so that newbies looking for basic anatomy information on their Cayennes would learn that the brake reservoir is under a panel below the windshield wiper.
2012 Cayenne S.
Car just won't start with the battery fully charged. When I try to start I hear a single click.. nothing else. I checked the battery and it shows 13.89v. All the lights inside including the dash, blinkers, tail light, headlights work just fine... but the engine is not getting any power I think...
I tried to jump start the car, but the car is getting no power whatsoever when I connect an external battery via the jump start terminals. Not even a single light... it's completely dead.
I think there is a disconnect between the main power distributor and the fuse box in the engine compartment. Could it be the relay 433 in the engine bay fuse box? If the relay goes bad, would it completely cut off the power to the engine?
Anyone has the wiring diagram? I'd greatly appreciate any help on this. Thanks!