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  #1  
Old 11-20-2015, 06:24 PM
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Valve Stem Seal Replacement Question

Hey all,

I'm in the process of replacing my valve stem seals on my OM617. So far so good, but I noticed that when I replaced the first two intake seals, the valves seem to slide down to the piston without any pressure, while the exhaust valves did not. Does this indicate worn valves? Should the valve stay in place unless forced downward? The previous owner/mechanic mixed up the seals (they put green for intake and black for exhaust). Also, are there torque settings for the rocker arms? Didn't see them in the FSM.

The car smokes pretty badly and has quite a bit of blowby. I'm excited to see if this is the cause. When I'm stopped at a light for a while and then accelerate, the car bellows smoke so this should improve that.
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  #2  
Old 11-20-2015, 06:41 PM
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Should help oil burning on acceleration. I would not worry about valves sliding down at various velocities. Probably just a little more worn guides on exhaust.
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  #3  
Old 11-21-2015, 05:48 AM
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A general rule of thumb =>

Pull the valve slightly out of the stem. If you can feel axial wiggle movement then the fit is not good.

I hope you realise that after installing new stems / guides you should have the valve seats re-cut and faced with the valves.
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Last edited by Stretch; 11-21-2015 at 01:33 PM. Reason: Made it a bit clearer
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Old 11-21-2015, 01:26 PM
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Wait a minute; I thought it was perfectly reasonable to install new valve seals in the valve wear was tolerable- looks like you are saying you have to rebuild the head instead...?
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Old 11-21-2015, 01:32 PM
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Quote:
Originally Posted by fahrvergnugen View Post
Wait a minute; I thought it was perfectly reasonable to install new valve seals in the valve wear was tolerable- looks like you are saying you have to rebuild the head instead...?
Well I'm saying if there's feelable wiggle then the stems / guides are probably done and a rebuild is probably in order.

Replacing the seals on worn parts isn't going to help.
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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!
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  #6  
Old 11-21-2015, 02:27 PM
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Ah, gotcha. Thanks for the clarification. I need to do this too; mine smokes a little.
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  #7  
Old 11-24-2015, 09:02 AM
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I just did my seals a couple days ago. I think vertical play is fine as the spring holds the valves up. Lateral play is what's important. I had zero, and the new seals almost completely eliminated the smoke in the valve cover.
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  #8  
Old 04-11-2016, 03:15 PM
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Quote:
Originally Posted by 300SD90 View Post
Hey all,

I'm in the process of replacing my valve stem seals on my OM617. So far so good, but I noticed that when I replaced the first two intake seals, the valves seem to slide down to the piston without any pressure, while the exhaust valves did not. Does this indicate worn valves? Should the valve stay in place unless forced downward? The previous owner/mechanic mixed up the seals (they put green for intake and black for exhaust). Also, are there torque settings for the rocker arms? Didn't see them in the FSM.

The car smokes pretty badly and has quite a bit of blowby. I'm excited to see if this is the cause. When I'm stopped at a light for a while and then accelerate, the car bellows smoke so this should improve that.
What companies Valve Stem Seals did you use?
Changing the Valve Stem Seals on mine did not have a obvious effect on the idle blow by.

Maybe you have another thread some where on what color the smoke is and if it smells like Oil or Fuel.
Also do you have Oil consumption issues?

Soaking the Cylinders with Marvel Mystrey Oil for over a Week cured the hazy gray smoke that I had all of the time on my Volvo Diesel.

However, doing the same with the Mercedes (no smoke but but has blow by) did not change the blow by.

The Water Pump leaked on the Mercedes while my Wife was driving and while she stopped and let it cool off she did not add more Water/Coolant and drove it to here destination and back.
While there is no catastrophic damage the blow by at idle is the same but it uses more Oil then it did.
I suspect the Cylinders got glazed and or the Piston Rings sofetend from the extra heat.

I mention the above because there is a few factors concerning smoke and Oil usage and fixes work only if you happen to target the problem.
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Old 05-03-2016, 09:11 AM
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Quote:
Originally Posted by Diesel911 View Post
What companies Valve Stem Seals did you use?
Changing the Valve Stem Seals on mine did not have a obvious effect on the idle blow by.

Maybe you have another thread some where on what color the smoke is and if it smells like Oil or Fuel.
Also do you have Oil consumption issues?

Soaking the Cylinders with Marvel Mystrey Oil for over a Week cured the hazy gray smoke that I had all of the time on my Volvo Diesel.

However, doing the same with the Mercedes (no smoke but but has blow by) did not change the blow by.

The Water Pump leaked on the Mercedes while my Wife was driving and while she stopped and let it cool off she did not add more Water/Coolant and drove it to here destination and back.
While there is no catastrophic damage the blow by at idle is the same but it uses more Oil then it did.
I suspect the Cylinders got glazed and or the Piston Rings sofetend from the extra heat.

I mention the above because there is a few factors concerning smoke and Oil usage and fixes work only if you happen to target the problem.
I apologize for my late reply. I used the Meistersatz valve stem seal set. I do have some blowby but unfortunately it did not seem to improve after the valve seal replacement. I'm assuming I have stuck or cracked rings, but it's not so bad that the car is not drivable.

Let me know if you have anymore questions.

Sent from my Nexus 6P using Tapatalk
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1978 Corvette Pace Car - 21k miles

2006 Mazdaspeed 6 - 56k miles
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  #10  
Old 05-21-2016, 11:39 AM
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Quote:
Originally Posted by 300SD90 View Post
...I do have some blowby but unfortunately it did not seem to improve after the valve seal replacement.
Have you fully seated those valve guide seals? Did you use the mandrel, or an alternative good enough approach (as I did?!)
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  #11  
Old 08-29-2016, 08:10 PM
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Quote:
Originally Posted by 300SD90 View Post
I apologize for my late reply. I used the Meistersatz valve stem seal set. I do have some blowby but unfortunately it did not seem to improve after the valve seal replacement. I'm assuming I have stuck or cracked rings, but it's not so bad that the car is not drivable.

Let me know if you have anymore questions.

Sent from my Nexus 6P using Tapatalk
Marvel Mystery Oil Soak Raises compression
http://www.peachparts.com/shopforum/diesel-discussion/355947-crankcase-pressure.html
Results of Marvel Mystery Oil soak by another member.
http://www.peachparts.com/shopforum/diesel-discussion/325761-i-didnt-kill-my-motor-after-all-maybe.html

The above only works if your got some sticking piston rings.

My Water Pump leaked while the Wife was driving and while she pulled over and let the Engine cool off she did not add more coolent and continued to drive after it cooled off till it got hot again and so on till she got home.

Luckly with a new Water Pump the Engine runs OK but I have slightly more blow by and it buns more oil then it previously did. I believe the overheating glazed the Cylinders and the resut is more blow by and oil buring.
I guess what I am saying is the blow by issue can be caused by at least a few individual things or a combination of them.
The main thing is if the Car runs OK and is functional in your daily driving.

There is threads on dealing with the blow by like piping it to another location.
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