Probe valve stem seals - head on or off?

[Kestas]

Can the valve stem seals on a Probe be replaced without removing the head? The car is a 94 Probe 2.0L-16V. I have a hand-held valve spring compressor.

 

[TheLoneRanger]

Kestas, I can't give you a definitive answer, but I would think the head could stay on. You just need to find a way to keep the valves from falling into the cylinders. The accepted way is to use compressed air. Another way is to stuff a piece of rope into the cylinder, with the piston at TDC.

 

[Kestas]

Thanks, that's what I told my buddy with the Probe. He was told the head has to come off... something to do with the cam seals or that it can't be done with the head on.

 

[ChrisW]

From what I remember on reading about replacing valve stem seals, you can do it w/o taking the head off.

You'll need an adapter to put in compressed air through the spark plug hole. And you'll need to make sure the cylinder you are working on is at TDC.

If air pressure doesn't hold the valve closed, then there is no other way to do it than to take off the head, as this means there is most likely valve seat damage.

You'll want to check the valve for eccentric wear; make sure the piston is at TDC, and then release the pressure once you have removed the keeper, seal, retainer and valve spring. Rotate the valve to check for wear, and up and down to make sure it doesn't bind in its travel path.