Have a weak exhaust spring #3, with rockers off about 1/16" lower than the intake side with no pressure on the valves. wishful thinking that it might not be bent valve although want the pro comp 910 springs anyway ( 130K miles). Would there be enough room to use a valve spring removal tool while running air to the cylinder to keep valve from dropping? Thought I'd try this approach before pulling head. Thank-Q once again, Ron

 

get the cylinder on compression stroke and feed a length of nylon rope into the glow plug hole (leave a tail obviously) and then bring the piston up to lock the valves in place using a socket on the crank. be sure the engine is cold)

I have done that on gas engines (via spark plug hole). the nylon rope is nice and soft and has limited compressibility so there is no damage. Just be sure both valves are closed when you bring the piston up or you will bend a valve.

Richard

 

Just bring the piston up to top.rope not needed.the limited combustion chamber size will not allow valve to move much at all.I never bother with the air.just a pain to deal with and not needed.

 

Valves drop down about a 1/4" mate less at TDC. Very possible to do, grab spring compressor or your tool of choice, lay down a few towels to catch a keeper incase you drop one. It's pretty easy, and a bit of advice is to smack the top with a rubber mallett to brake loose the keepers seat and when it's back together I like to smack it again to make sure they are seated.

 

Read an article in Dieselpower mag and I believe they had to jack up the motor a bit to get the passenger side rear spring out.

 

If you set the piston at TDC with a small amount of air added , you will be able to tell if the valve is bent depending on where you hear air leaking...

Then with high air pressure in the cylinder , you can safely remove the valve spring , if the valve is not bent ...

 

Thanks everyone for the insight, i feel confident now in this and sounds almost easier than I originally thought. When installing brand new springs , is therr any need to shim them for a 130K mile motor? Not from a performance approach, just from the pre- existing wear on the valves themselves. This is the only aspect yet to determine. Thanks again, Ron