04-20-2012, 10:07 PM
No, I really don't know when it ocurred in cars. I'd think at the same time. I noticed on my 92 968 that seals like the oil cooler o-rings all appear to be Viton, and I believe them to be original. Key is to make sure if you are replacing seals to use a fluoroelastomer if you are going to use a synthetic oil.
Also, I'd suggest as I think you are planning to wait until the belt retighten time frame before you do the seals. There is some chance it will burnish a surface if it just a surface finish problem and the leak may go away. And, be real careful when installing new seals to have everything as clean as you can get it, and lube the seal with some grease of the like that is compatible with the engine oil. It helps avoid cutting or maring the surface of the seal which could lead to leaks.
I'm personally of a mind if a seal isn't leaking to at least consider leaving it alone. It's too easy to just mass change seals, even functional ones when you are working on an area of an engine, just to end up with worse results. Just my 2 cents.
Also, I'd suggest as I think you are planning to wait until the belt retighten time frame before you do the seals. There is some chance it will burnish a surface if it just a surface finish problem and the leak may go away. And, be real careful when installing new seals to have everything as clean as you can get it, and lube the seal with some grease of the like that is compatible with the engine oil. It helps avoid cutting or maring the surface of the seal which could lead to leaks.
I'm personally of a mind if a seal isn't leaking to at least consider leaving it alone. It's too easy to just mass change seals, even functional ones when you are working on an area of an engine, just to end up with worse results. Just my 2 cents.

