Can / how do you replace valve stem seals in an assembled engine?
 

Is it possible to replace the valve stem oil seals in an assembled engine?

If I had the Porsche valve spring compressors, which bolt to the cam tower studs. I could remove the springs.

But would I have enough room to pull off the seals and install new ones?

Any special technique? Any special tool to remove and install the seals?

Look for Scott98's post.........
 

Exactly what you need to do is this post.
HTH.

Tony

? Was there a link that didn't copy over ?

Or did I describe exactly what to do ?

I'd bring this over to the engine rebuild forum.

You decided it's definitely valve stem seals huh? That sucks.

BTW, I think I'd strongly consider Henry's suggestion of polishing the valves if they have the radial grooves as you mentioned. I'd hate to go through the work of replacing the valve stem seals only to have them damaged by the valves again if that's what caused it.

Here's a thread I found and it looks like it certainly is possible
http://forums.pelicanparts.com/porsche-911-technical-forum/490990-replacing-valve-stem-seal.html

Another;
http://forums.pelicanparts.com/porsche-911-technical-forum/30765-replacing-valve-stem-seals-engine-car.html

I was debating engine rebuild vs general tech audience. Pelican discourages cross posts, so I am stuck for now. You are right. Better in the rebuild section.

Can the moderator move it???

My thought is to attempt to replace the seals. But, I can check the guides for looseness. If the valve guides are worn, then a full teardown. If not, fix the seals and go on with life.

Being your top end is new IIRC I'd have to be concerned about what took out the seals in the first place. IDK if I wouldn't drive it through the season as a mosquito fogger and do a tear down during the off season and try to find what took out the seals.

No link attached......
 

Just search for Scott98's posts and you will find a very nice thread for your need. It got pictures and all the information you will need to do to replace valve stems seals in situ.

Tony

I think this is the thread boyt911sc is mentioning.

http://forums.pelicanparts.com/porsche-911-technical-forum/376231-installing-new-valve-stem-seals.html