Need Help with VIN# for Gasketed 3.6L Heads

[SeaDweller]

I understand that one of the issues with the 964 3.6L engines was the lack of head gaskets in the first year or two. Evidently, they relied on the perfection of machined surfaces to provide a leak-free seal. I also understand that in mid-'91, Porsche started installing gaskets on the 3.6L engines.

Regarding a '91 car, can you tell by the VIN# of the vehicle if it has the updated engine, or do you need the engine #? If you can determine this by VIN#, does anyone know which number was the first car to have the update?

Thanks!

[Eric Coffey]

All I could find were references to engine numbers, not VIN's. It looks like the first engine with the update (new pistons, cylinders, and machined heads for gaskets) was: 62 M06836, M64.01 (manual transmission).

[Britwrench]

A fair few of those cars were updated by either Porsche or the owner so earlier cars may already be done. Of course, dependant on condition, they can still leak oil from several other places....

[Eric Coffey]

Yeah, Porsche basically fixed what wasn't broken, and it ended up costing them millions.

[JeremyD]

Yeah, but plenty didn't show up till later either - especially in warm climates when they had the engine pan on - sitting in traffic - etc.

Engine number on the right side by the fan if I remember correctly.