Engine Rebuild/Replacement

Hal Hamilton · 05-06-2009, 01:31 PM

I have a 2004 Cayenne S, the dealer has just informed me the number 8 cylinder is scored (engine was knocking). They only propose a new engine.

Anyone have any experience with rebuilding Cayenne engine. Can anyone recommend a re-builder.

JHoffman · JHoffman's Garage

How far out of warranty are you? I highly recommend that you ask this to be goodwill. If they say no then contact porsche yourself. Make sure to be polite. Chances are they will pay parts if you pay labor.

Hal Hamilton · 05-06-2009, 03:09 PM

Good point, it has been off warranty for about a year. Not sure dealer will assist but approaching porsche may be worthwhile.

vadimkag · 05-06-2009, 05:21 PM

Haw did that hapend? Low on oil?

ChkbookMechanic · ChkbookMechanic's Garage

Wow, sorry to hear this has happened to you. I don't know any rebuilders that specialize in the Cayenne engines. Like JHoffman, I think it is probably best to talk to Porsche first. If that doesn't work perhaps talking to one of the 911 engine rebuilders on Pelican might be worthwhile (Supertech, LN Engineering, etc)?

Hal Hamilton · 05-07-2009, 05:36 AM

No engine always ran fine, dealer serviced.

stealthn · 05-07-2009, 09:33 AM

Hi Hal, Bob from Calgary; wow that's a drag. Was it SS that said replace engine? How do they say it got scored? I can only image a failed ring, if so I would think this should be replaced by Porsche.

Please keep us posted as to what happens.

vadimkag · 05-07-2009, 02:55 PM

Thats sckery...

rich · rich's Garage

The new guy again. Sorry to here about your engine failure. What is the block material made of? The 928 block is Alusil. I had a 928 block bored out here locally and fitted over size pistons. Porsche could likely have a + size piston that is in the correct weight and tolerence group. Maybe you can just do one piston. That's what they did for the 928.

ChkbookMechanic · ChkbookMechanic's Garage

The Cayenne v8 block and heads are aluminum. I don't know if they coated the cylinders with Nikasil or one of those other materials the Germans seem to like to do.

As an option, Gemballa is offering a 5.0L kit for the Cayenne V8 engine...

Best of luck whichever route you go Hal.

stealthn · 05-30-2009, 06:24 AM

Any update Hal?

stealthn · 06-05-2009, 05:10 AM

Hal,

Are you getting this done at Alpine. I spoke to them yesterday about doing some work for me and they said they are replacing an 04S engine, all week.....

Merk · Merk's Garage

I have an 04 Cayenne S- 69,000 miles and the engine is knocking due to a scored cylinder. Dealer says only fix is to replace engine. Any alternatives?

rich · rich's Garage

Here's a useful link. Rheinmetall AG - Cayenne engine block delivered "ready-for-engine-assembly": added value through ATAG project

The blocks are Alusil like the 928. In order to bore the block and use Forged pistons you would need to either find a 5.0 piston with the iron coating on the skirt or have the block bored and have the cylinders coated with nickasil. There may be after market pistons someplace that will run in the Alusil bores but so far the 928 guys are having their cylinders nickasil coated.

Merk · Merk's Garage

Thanks Rich.

Simondale88 · 12-08-2009, 10:19 PM

Thanks for the information!

rich · rich's Garage

You should check with the Porsche parts dept. to see if there is an over size piston and ring set available to repair the errant cylinder. Back in the day it was possible to purchase 1 plus size piston/ring set for the 928. The pistons were made in tolerance groups and weight ranges so it was possible to get a slightly larger piston that would be within the correct weight to maintain balance. The engine would have to be stripped to the bare block, the errant cylinder could be bored out slightly to the correct size for the new piston and then reassembled.

The problem is the cost of dealership labor for a teardown and re-assembly may be why they are suggesting the replacement engine.

If you find a shop that is cheaper than the dealer then you also need to locate a machine shop that is either willing to try to bore and hone the alusil or a shop that has done it before.

I had a 928 4.7L block bored to 5.0L locally at the Chevy guys shop. These guys never even saw a 928 block before but I provided them with all the factory specs and boring instructions and honing procedures. They did a great job. I would not hessitate sending another block to them.

You may be able to have one cylinder resized to factory specs also. I think you can get an alusil sleeve. This involves over boring the block and pressing in the sleeve. Then the sleeve is bored and honed out to the factory specs.

Are you sure it's a piston problem? I would be skeptical of that diognosis without a tear down unless the mechanic looked into the cylinder with a camera. Lots of things could sound like a knocking piston. Like a connecting rod... valve seat, etc.

Merk · Merk's Garage

Rich-

Thanks for the post.

They did scope the engine and ran video to do the diagnosis. I am guessing they are right on the issue and tearing down the engine would involve the labor to do so with the same diagnosis. Plus my Service Manager told me this is a problem with the 04 Engines.

I will check on the oversized piston and ring set. I would send the block to MN to be rebuilt if the cost was less than the remanufactured engine. Problem I fear is if it happened to one cylinder it could happen to another so just boring out the faulty cylinder is a risk.

The quote for the engine is $7,800. The labor estimate brings the whole job to $12,700 assuming no other issues. At that price I have no choice than to sell it for parts and start over.

rich · rich's Garage

What is the shop rate? I'm guessing $100.00 hr? Is that a New Engine from Porsche?
I would look for a small shop on the outshirts of town with a shop rate around 60-70.00. Then shop for a used long block. You could install a 05 or newer if Porsche actually corrected the problem. Otherwise.. You may be able to get a used engine for less through a smaller shop.

In any event, it sux.

Merk · Merk's Garage

Dealer Rate is 110 and the other shop is 90. I think I have a line on a used engine through a friend of a friend who has a parts yard/ body shop/ repair shop. He could maybe do it for less but a used engine with 30,000 miles is $6000. I am working with Porsche USA and they are reviewing my request for some consideration on the engine. I'm keeping my fingers crossed.