Valve Guide Seals For a Diesel - PeachParts Mercedes-Benz Forum

sublettd · #1 01-27-2003, 03:10 PM

Just replaced valve guide seals on the SL and noticed my 300D is putting out smoke on start-up, which it never did before. At least not this much. Engine has 277,000 miles on it and never had any work done to it. Still going strong, but wondering if valve guide seals is a repair that is done on diesel engines, or is solely for gasoline ones??? Thanks.

#2 01-27-2003, 03:24 PM

Yes, it is done on diesels as well. Some engines respond to this and some don't. You just don't know 'til you try.

Assuming the engine has never been apart, if the compression is still good on this engine, it would be a worthwhile project to remove the head, and have a valve job done with new valve guides.

Good luck,

leathermang · #3 01-27-2003, 03:31 PM

I think it is worth a shot by itself... just the seals... you may get another 100 k out of it before the guides would have to be done..It is not too bad a job to do the seals... just be sure to follow the directions and use the plastic protective (throw away) sleeves to protect the lips of the seals... and be sure they are as far down as they should be .... they are very inexpensive ,, just the trouble of taking the springs off the valve tops....used to be there were one color for exhaust and one for intake... but I think they all are the same color now....

sublettd · #4 01-27-2003, 06:22 PM

Guys,

Appreciate the suggestions. Will talk to my mechanic about what he suggests. For sure, it's not something I would attempt. Learned my lesson(s) a long time ago and have figured out I save money by knowing my limitations. ha!

Jeremy5848 · #5 07-27-2007, 12:24 PM

Are there any snake oil products (with "miracle" in the name, as Click and Clack say

) that might swell the valve guide seals temporarily? Our '87 300D-T smokes a little at startup and under acceleration and uses about 1 quart of oil per thousand miles. There is no evidence of a cracked head. The compression (rings and valves) would seem to be good -- the engine starts easily. Even with no pre-glow, it will start at 60F after about 5 seconds of cranking. The turbo is new (found bad by dealer and replaced as part of trap ox recall). We plan to get rid of the car when we have found a better one and I don't want to put any more money into it, such as by replacing the seals.

#6 07-27-2007, 01:54 PM

Quote:

Originally Posted by Jeremy5848

Are there any snake oil products (with "miracle" in the name, as Click and Clack say

) that might swell the valve guide seals temporarily?

Think about what you are asking for. If you put something in the engine to swell the valve stem seals, those aren't the only seals that are going to swell from it.

Jeremy5848 · #7 07-27-2007, 02:42 PM

Quote:

Originally Posted by ForcedInduction

Think about what you are asking for. If you put something in the engine to swell the valve stem seals, those aren't the only seals that are going to swell from it.

Your point is well made, but.....the risk is....?

#8 07-27-2007, 03:02 PM

Swelling also softens gaskets and o-rings. What other gaskets could swell? The oil pan gasket, oil filter housing gasket, valve cover gasket, front main seal, rear main seal, injection pump mount gasket, shall I go on?