Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-16-2010, 12:07 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 57,010
I think I have figured out a way to change the Valve Guide without removing the Cylinder Head.

But, please remember I am not there to see it and I have not had a Mercedes Cylinder Head off or changed any Valve Guides on a Mercedes.

Remove from the Head what ever parts are needed so that you can get at and remove the Valve springs just as it is in picture in the original post.

Rotate the Engine by hand and let the Valve drop down enough so that you can use a Tap to thread the inside of the Valve Stem Guide.
Use a Slide Hammer and pull out the Valve Stem Guide.

Do what ever is needed to clean out the Valve Stem Guide hole.

Rotate the Engine by hand to TDC so that the Valve is all the way up.

You will need some sort of Tube that will allow you to drive in the new Valve Stem Guild and not mess with the Valve.

Slide the new Valve Stem Guide over the Valve Stem and drive it in.

Put on the new seal and assemble the Head.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #2  
Old 06-16-2010, 01:47 AM
Registered User
 
Join Date: Aug 2009
Posts: 17
Quote:
Originally Posted by Diesel911 View Post
I think I have figured out a way to change the Valve Guide without removing the Cylinder Head.

But, please remember I am not there to see it and I have not had a Mercedes Cylinder Head off or changed any Valve Guides on a Mercedes.

Remove from the Head what ever parts are needed so that you can get at and remove the Valve springs just as it is in picture in the original post.

Rotate the Engine by hand and let the Valve drop down enough so that you can use a Tap to thread the inside of the Valve Stem Guide.
Use a Slide Hammer and pull out the Valve Stem Guide.

Do what ever is needed to clean out the Valve Stem Guide hole.

Rotate the Engine by hand to TDC so that the Valve is all the way up.

You will need some sort of Tube that will allow you to drive in the new Valve Stem Guild and not mess with the Valve.

Slide the new Valve Stem Guide over the Valve Stem and drive it in.

Put on the new seal and assemble the Head.
Isn't that more or less what i said in the fist post minus the removing the bad one part?
I think you would probably lose the valve when you tried to pull the sleeve. There isn't really much clearance between the cam and the valve guide hole. You'd have to get teh vavle way down and even then you'd probably need to pull the cam in order to apply any significant pressure to the new guide. But I've heard people say that one can fish out a valve with a magnet (sounds like almost as much fun as pulling the head :-P)
I also get the feeling that that guide is not a Mercedes one. It's machined flat on top and the valve closes all the way (the car runs well except the oil smoke on start). The mercedes ones are slightly beveled and so long that the valve wouldn't close with it shoved way down in there. I suspect its a machined bronze or brass ring that was put in there with some force (do they do this on other cars?). I wish someone could give me an answer that sat right with me. But I'm the first to admit that I'm an amateur and probably don't know what I'm talking about.

Anyhow doing that and risking making an engine that works with its head onl into one that doesn't work without pulling the head to fix it right (or replace it!)doesn't really seem worth it when the only issue i have is oil smoke on start and moderate oil consumption in a car I paid 1000 for.

Thanks for all the help and advice.
Reply With Quote
  #3  
Old 06-16-2010, 02:44 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 57,010
Quote:
Originally Posted by soulbandaid View Post
Isn't that more or less what i said in the fist post minus the removing the bad one part?
I think you would probably lose the valve when you tried to pull the sleeve. There isn't really much clearance between the cam and the valve guide hole. You'd have to get teh vavle way down and even then you'd probably need to pull the cam in order to apply any significant pressure to the new guide. But I've heard people say that one can fish out a valve with a magnet (sounds like almost as much fun as pulling the head :-P)
I also get the feeling that that guide is not a Mercedes one. It's machined flat on top and the valve closes all the way (the car runs well except the oil smoke on start). The mercedes ones are slightly beveled and so long that the valve wouldn't close with it shoved way down in there. I suspect its a machined bronze or brass ring that was put in there with some force (do they do this on other cars?). I wish someone could give me an answer that sat right with me. But I'm the first to admit that I'm an amateur and probably don't know what I'm talking about.

Anyhow doing that and risking making an engine that works with its head onl into one that doesn't work without pulling the head to fix it right (or replace it!)doesn't really seem worth it when the only issue i have is oil smoke on start and moderate oil consumption in a car I paid 1000 for.

Thanks for all the help and advice.
I figured that ounce the Old Valve Guide is out there would be plenty of room to "find the Valve"; and a Magnet would work.
I also believey you would need to remove the Camshaft remove and install the Vlave Guide.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #4  
Old 06-16-2010, 01:53 AM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,642
if you are really upset by the smoke [which you assume is oil] , you could modify a valve stem seal to lay under the 'bearing' or 'rotocap' that sits under the valve spring.

the only thing you can do is wipe the oil off the stem before it reaches the guide.

Another thought is a large rubber washer , maybe viton. Regular black rubber will not last long under those conditions.
__________________

Reply With Quote
  #5  
Old 06-16-2010, 02:49 PM
Registered User
 
Join Date: Aug 2009
Posts: 17
Quote:
Originally Posted by jt20 View Post
if you are really upset by the smoke [which you assume is oil] , you could modify a valve stem seal to lay under the 'bearing' or 'rotocap' that sits under the valve spring.

the only thing you can do is wipe the oil off the stem before it reaches the guide.

Another thought is a large rubber washer , maybe viton. Regular black rubber will not last long under those conditions.
You know I had the same exact thought after I put the valve cover back on. The oil smoke bugs me, mostly because i want to sell the car and it looks tacky when a cloud of smoke comes out as you start it. Oh well, after spending three days with it apart (i work slow cause its hot here) and stripping the oil filter lid stud )DOH(. I'm not all that motivated to take the vavle cover/valve spring off again.
Reply With Quote
  #6  
Old 06-16-2010, 02:54 PM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,642
Quote:
Originally Posted by soulbandaid View Post
You know I had the same exact thought after I put the valve cover back on. The oil smoke bugs me, mostly because i want to sell the car and it looks tacky when a cloud of smoke comes out as you start it. Oh well, after spending three days with it apart (i work slow cause its hot here) and stripping the oil filter lid stud )DOH(. I'm not all that motivated to take the vavle cover/valve spring off again.

honestly,

it probably is not worth your time. The whole point of having the valve stem rise above the rotocap is because that area fills with oil.

Having a valve guide cut off flush with that surface severely limits your options to making an effective seal... ever... without removing the head.
__________________

Reply With Quote
  #7  
Old 06-16-2010, 03:07 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 57,010
This is going to be hard to describe.

You take a shortened piece of a Valve Guide; the part with the lip that holds the Valve Stem Seal on; you would have to figure the length.

you Braze that piece of Valve Guide to the thin washer (the washer needs to be like sheetmetal thin so the Valve Springs sitting on top of the washer do not become coil bound) about the outside diameter of the hole that the Valve Springs goes in.

When you install it you put a coating of Silicone Sealant on the Bottom of the washer and slide it over the Valve Stem. Followed by the Valve Stem Seal.

The Valve Spring will sit on the top of the Washer pushing it down and the Silicone will prevent Oil from getting under the Washer. Since the section of Valve Guide is Brazed to the Washer it will not leak there.

The Valve Stem Seal should seal the Valve Stem itself.

The main rub is that the new Brazed on section of Valve Guide is going to have a tigher ID than the old piece of Valve Guide that is still in the Head; so there would be some side ways force exerted on it when the Valve goes up and down.
It would work best if the hole in the Brazed on section of Valve guide was enlarged so it would not touch the Valve Stem so no sideways force could break it off at the Brazed joint.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #8  
Old 06-16-2010, 09:38 AM
Alastair's Avatar
Registered User
 
Join Date: Mar 2002
Location: South Wales U.K.
Posts: 1,064
Might be easier to pull the Pre-Chamber, bang the valve-guide out into cylinder, and fish it out with a Magnet on a stick!

--All depends on whether the Valve will drop outta the guide with the Piston at BDC--If it wont, then this idea wont work....

Driving in the new guide after the old is out is easy, and getting valve back up isnt hard with long-nose through manifold tract in head after you have the manifolds off....

Problem may be that with the New Guide fitted, the Valve wont seal properly without re-lapping/facing it in, as it may not be in Exactly the Same position as the Old, Worn guide,--With the small side-force on the valve-stem imparted by the follower, the valve seat after a few hundred K miles wears slightly eccentric.....
__________________
http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....
Reply With Quote
  #9  
Old 06-16-2010, 11:21 AM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,642
I agree with Alastair, except that pulling the prechamber will not help you remove the valve guide, really.

and that guides usually need a good reaming before the valve slides easily.


you cannot (properly) install a new valve guide without removing the head.

work with what you have.
__________________

Reply With Quote
  #10  
Old 06-16-2010, 03:06 PM
Registered Hack
 
Join Date: Mar 2008
Posts: 4,642
actually, post #22 by D911 is the only fix worth trying.

it is rife with potential failures and you will need some very precise work done... but it is the quickest / least invasive solution.
__________________

Reply With Quote
  #11  
Old 12-02-2013, 02:47 PM
whunter's Avatar
Moderator
 
Join Date: Dec 2003
Location: Metro Detroit, Michigan
Posts: 17,432
Recycled

for new owner.

.
__________________
ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
2003 Volvo V70

https://www.boldegoist.com/
Reply With Quote
  #12  
Old 12-03-2013, 03:54 AM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
Link to the same discovery

Check this posting out...specifically post #53 on page 4. I found the exact same thing. White smoke and all. The seat was wallowed out pretty good and needed a full valve job. I think we drove this car for a long time like this, maybe even since we got it until the headgasket let oil into the coolant. The car ran good, up to that point.
85 300TD blown headgasket?
Reply With Quote
  #13  
Old 12-03-2013, 03:19 PM
Smoker's Avatar
Fast Attack Submarines
 
Join Date: Aug 2013
Location: South Central Florida
Posts: 473
And here I was thinking I was unique....seems the broken guide is not uncommon. I sure wish Roy lived near North Carolina though, even having done it once now I believe I'd still rather hire a pro to do that job.... Although I'm planning on a full 617 rebuild just because I'm crazy....and Stretch needs competition from this side of the pond.
__________________
Eric, CPO, Submarines, retired.
Here's a sig line...
Mine: '68 Corvette LS1/4L65E, 83 240D, 2000 GMC 4x4, 08 FLSTC Anniv
Hers: '72 Corvette 454/4spd, '99 MB SLK, '93 Metro vert, 78 240D, '92 Silverado, '65 Fjord Rustang, '59 Fjord Fairlane, '17 Slingshot.
Reply With Quote
  #14  
Old 12-03-2013, 03:55 PM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
Yea stretch is the man to consult for the finer details. I just got through reading some of this thread:

OM617 manifold oil = broken valve guide

Best check this one out when you do this job. After reading this thread I found myself asking myself these questions....Why did'nt I check to make sure the valve springs were installed correctly?....and would valve lapping be considered something I should have expected the machinist to do when he rebuilt my cyl. head last summer? He did charge me for a complete valve job....and I did'nt do it...d-oh

In hindsight I really wished I had access to that thread at the time. I have also wondered if I should be consulting Stretch for everything from now on....man, that guy pays attention to the small details. Forgive me for saying that Stretch should have his own site, for all the documentation he has done here. That in itself is alot of work. If I have'nt mentioned it before, Thanks, Stretch for all your contributions to this site...and everyone else for that matter. Stretch seems to stretch the extra bit on the details...I appreciate it. He is valuable part of this site, and he takes awesome pictures. Roy too, He has always been here and sometimes gets left out and taken for granted cause thats what happens to old faithful. He's gone to great lengths to be there for some of us including taking personal phone calls, wow.

Without guys like these, to offer (free) their knowledge, some of us could'nt afford to own one of these vehicles. They go above and beyond, and are inspiration. Oh new thread idea.

Last edited by macdoe; 12-03-2013 at 04:10 PM.
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 12:44 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page