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#1
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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.
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84 300D, 82 Volvo 244Gl Diesel |
#2
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Quote:
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! ![]() Thanks for all the help and advice. |
#3
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Quote:
I also believey you would need to remove the Camshaft remove and install the Vlave Guide.
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84 300D, 82 Volvo 244Gl Diesel |
#4
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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. |
#5
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Quote:
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#6
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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. |
#7
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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.
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84 300D, 82 Volvo 244Gl Diesel |
#8
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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..... ![]()
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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 ![]() ![]() |
#9
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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. |
#10
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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. |
#11
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Recycled
for new owner.
.
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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/ |
#12
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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? |
#13
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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.
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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. |
#14
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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. |
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