617.952 vs. 617.951 Valve Stem Seals
 

I had an old set of Meistersatz valve stem seals, part number 617 050 00 67.
The intake seals are metal with only a black rubber top.
I looked up the part number, and the site said it was for a 617.951, though it fit a 617.952. I got them on, but the seals were very tight. Pressing them on by hand was impossible for most, and I had to help them over the stem groove by hammering on the tool.

The valve stems slip in the seals okay, and I don't think the seals are going anywhere.

Has anyone else installed the 617 050 00 67 kit in their 617.952, instead of the 617 586 04 05 kit? Do I have anything to worry about?

Valve Stem Oil Seals
 

? Is there a pictorial how to do this job ? .

I was bombing down a steep incline in second gear to day and noticed a blue cloud behind me......:rolleyes:

https://www.startekinfo.com/StarTek/outside/12265/disc_2/program/Engine/617/05-270.pdf

I've found that a bent Hazet valve adjustment wrench will slip under the old seal to help you pry them up and pop them off with a screwdriver.

Just know that the engine needs to be pushing the piston you are working on to the top. That means the relevant cam lobes need to be in the "five-'till-three" position, with the intake being the minute hand, and the exhaust being the hour hand. Do one cylinder at a time, and watch the firing sequence (Zündfolge) on the cam cover. Printing out a map of the valves is also a good idea.

The FSM mentions being sure to get the newer valve stem seals... ' newer gas lip ' design..
and that ' seal assembler' shown in the startek reference above is the standard method for applying enough pressure in the correct direction..
NOTE... plastic sleeves are used to protect the valve during this procedure... and should come with your seals...

I hate second-guessing myself, especially after getting the fan an rockers back on and the valves adjusted. Working on those fan screws is like breaking out of prison. It's bothering me, though. Those seals went on a lot harder than they should have.

I would not be particularily concerned. On our diesels for a few reasons the valve seals are not as important as on the gas engines anyways. As you are probably aware the intake valve guide on a gas engine has a vacuum present to draw any oil down the guide.

Our diesels actually apply pressure from the turbo to push oil back up the valve guide if any ventures down. Even a non turbo diesel has no intake vacuum.

The best valve seals you can buy for a Mercedes gas engine are good value. For their diesels not so much. There is constant exhaust pressure against the exhaust valve guides on both types of engines. So they are not a signifigant issue usually.

Some diesel engines with a lot of crankcase blowby. Can be partially attributed to worn valve guides and shot valve seals. Most assume a lot of blowby out the oil filler cap present is always just leakage past the piston rings. Never considering some of it might be created by pressures getting out of the very worn valve guides. When the valve guides are badly worn the valve seals have difficulty dealing with the situation. They can wear fast. The original seals must have been very good as well. Many engines probably still have them after all these years. It may be there is less heat in the valve guide with a diesel . Most gas engines would have made them totally rotten after this much time and average accumulated milage.

.951 and .952 share the same valve train and cylinder head casting....

So, what's with the different valve stem seals?
Here's a picture of an intake seal as far as I could get it by just pushing it down.
I've ordered a new 617 586 0405 set and will install that as soon as it arrives.
http://i1376.photobucket.com/albums/...psp7fguysx.jpg

What did the original look like? Do you have a pic to show the difference?

I opened it back up and removed the seals from cylinder one's valves. I guess I should have noticed this earlier, but the insides of the seals are not even complimentary to the features of the parts they are slipping onto. Both seem to have female-side indentations to fit ridges or lips from the other side. An O-ring fit into that gap would be a stunt.http://i1376.photobucket.com/albums/...ps0isvh23x.jpg

The originals were the typical hard rubber that we're all familiar with. Here's a picture of one being pried up using a valve adjustment wrench. http://i1376.photobucket.com/albums/...psenelaqas.jpg

Any oil present cannot flow up through the base of the valve stem seal on one of our diesel engines. So any seal there would be without purpose in general. The internal blowby pressure would have to be higher than both the exhaust stream and turbo pressures.


Perhaps that is why the design of the injection pump shutoff was designed to shut down if that kind of pressure was built up in the crankcase. Anyways it would be expected for a metal set to be a very tight fit. There is no way they can easily expand to hold on tight otherwise. Like the all rubber ones do.

Your choice to change them out or not. At the same time they might have been just an alternative seal for your engine. Great pictures as well.


These seals might have troubled me on a gas engines intake valves. Especially if they were not a really tight fit.

Yes, he did not mention the sleeves. The Meistersatz kit I got for the 617-952 came with 3 or 4 of the mentioned sleeves and I don't recall any odd issues installing them.

The attached pic shows the one that I bought over 5 years ago for my 617.952.

The pic is one of the ones that came up when I did a image.googel search = Meistersatz valve stem seals, part number 617 050 00 67

The I guess newer one has the same part number.

The pictures of the ones at this site look like the ones the OP used. I know the part number is different but the seals have the steel outer sleeve on them. Valve Stem Seal Kit 6150500067 - D P H - Mercedes-Benz - 615-050-00-67 | Pelican Parts
But, there is 8 in the set making me think it is for a 4 cylinder.u

I used a pipe bushing similar to the one in the last pic to push down on the Valve Stem Seals. Don't remember what size.

Valve Stem Seals of the same construction are shown at ******** AZ the pic shows a different part number with enough for a 4 cylinder but notice the maker. 6150500067 VictorReinz - Valve Stem Seal Set