Porsche Enthusiasts Club Forum

Hi I have a 2004 cayenne s with 88,000mls engine is ticking I have inspected the bores and all are scored in some way.
I am thinking of boring the engine to accept top hat liners & forged pistons has anyone heard of anyone else doing this as it,s a lot more economical than re,plating or a short motor.
please feel free to tell me your thoughts.
cheers Paul

These engines should be good for over 500,000 miles with a good quality oil.
Have you carried out a compression a leaking down test yet ?

Not really a lot of point in a leakage test with cylinders as badly scored as this its only a matter of time before a partial seizure or total piston destruction occurs.
I agree these engines should be good for plenty more miles but with inferior products used in the production process & the combination of super scrimpers doing the servicing on a budget or just using the wrong grade of oil it shortens the life by a vast amount.

When I was looking at a Cayenne I was told that a few engines have failed in this way. Normally starts as a light tapping noise, which is piston slap then gets worse. The 911 & PW buying guide alluded to this as well. The costs of rebuild would be horrific personally I'd get another engine from a write off.

I have looked round at engines out of write off,s but you are taking a big chance it may go the same way sooner or later with the dreaded tap. I think better the devil you know so I will probably rebuild this one.

Engine now removed & stripped cyls 2 & 3 6 & 7 all very badly scored & significant play causing a tapping sound contacted Porsche uk about the problem was advised they would consider goodwill if I pay the labour for my local OPC to fit new block.
the price was more than the vehicle is worth.
So engine is having top hat liners fitted & bored to original size, new custom made pistons to suit the liners & a full rebuild the story continues.......

A year after the project started
Top hat ductile liners fitted to block & decked.
8 new custom pistons manufactured in america
engine rebuilt new shells chains guides & gaskets all valves ground & heads rebuilt.

Engine fitted last weekend runs & drives like clockwork now done 110 miles running in is boring cant wait to open it up.