Discussion Starter · #21 ·
Hmm. I couldn't get the generic valve spring compressor to work on the shrouded valve springs so have to wait for the specialist tool to arrive. If I get the spring off and find the valve seals are good I am all out of ideas. Probably should pop the valve cover back on and proceed with the compression tests. I am trying to order some factory seals but they are confused themselves about which ones fit. I have only ever seen bad stem seals on cars that were abused i.e. no oil changes, no servicing, overheated etc. but that just doesn't look like what I'm seeing on top of the cylinder head which looks about as clean as anything I've looked at over the years.No preference really. The ones in the picture look more "high end" than the ones on both of mine. Mine look the same but don't have the little spring tensioner on the top where it seals the valve stem. The factory ones are like the ones I have on mine. FWIW, when I pulled my 6.1 heads with 165K on it, the valve seals were all still good, pliable and no oil getting past them.