300SD OM617 Valve Seal Replacement Help - Page 2 - PeachParts Mercedes-Benz Forum

Diesel911 · #16 06-23-2014, 05:21 PM

Quote:

Originally Posted by BillGrissom

Good info. I never thought about changing them. What symptoms tell you they need changing, other than cracked rubber pieces sitting on the head? In a gas engine, a bad seal will suck oil into the intake and cause blue smoke after sitting long at a stop light. In a diesel, there is almost no intake vacuum to suck oil, plus it would likely burn just like diesel, so are the valve stem seals essential?

In My case I believed that it was exhaust gasses getting past the Exhaust Valve stem Seal contributing to the Blow-by gasses.

If chainging them helped reduce Blow-by it was not enough for Me to tell.

When I did it many years ago the Miestersatz (spelling?) seal kit was about $17 with no shipping as I bought enough other stuff to get free shipping.
So it was cheap to see if the Seals were the cause of some Blow-by.

MSGGrunt · #17 06-23-2014, 10:10 PM

Well, I was able to get all the other valve stem seals on other than the one with the messed up nut. I'm going to try using a dremel with a small cutoff wheel to cut a split in the nut where the groove is in the valve stem. Hopefully this will be enough to allow me to twist off the nut without damaging the valve stem threads or without taking the cam off.

MSGGrunt · #18 06-23-2014, 10:19 PM

I'm not sure what a bad valve stem seal looks like, but all of mine looked to be in pretty good shape.

MSGGrunt · #19 06-24-2014, 10:09 PM

I was able to cut a "relief" slot in the adjuster nut and with very little force was able to get it off. I tried to protect everything as much as possible and when done cleaned everything up as much as I could.

MSGGrunt · #20 06-24-2014, 10:20 PM

Now the question is, do I need a special nut to replace this jam nut? Will any metric nut work or is this special, like hardened or something? I don't have a larger order to place to justify shipping and my nearest MB dealer is an hour away.

Diesel911 · #21 06-24-2014, 11:41 PM

Quote:

Originally Posted by MSGGrunt

Now the question is, do I need a special nut to replace this jam nut? Will any metric nut work or is this special, like hardened or something? I don't have a larger order to place to justify shipping and my nearest MB dealer is an hour away.

I would not take a chance on not using Nuts made for the Job.
The Upper large Nut has a handed tip on it and the lower one is thinner that a regular Nut.
Also on My Year and Model the Valve Rotates. So you don't want anything giving because it is too soft and then having the Valve Rotation turn the Nuts.