Is there any solvent you would recommend for cleaning the top of the piston and valve? Should I attempts to scrape it off?

You have E-mail.

Enjoy.

.

Never any compression? I thought you got compression with oil in it?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

kerry,

Sorry, you are correct. When I squirted oil in the injector port, I did get a compression reading over 300 psi. If I waited 30 minuted and did it again, I got no compression.

That caked on gunk looks like there has been oil leaking into the combustion chambers - or perhaps this is how an engine looks after running WVO? I don't know...

Here are some pictures of my engine with a busted valve stem that caused a bit of problem!







So OK these picture show a much wetter combustion chamber but I hope they demonstrate my feelings of built up oil shown in your pictures

Attached Thumbnails

     

__________________
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!

Here are all the photos. I'd rather them be on the peachparts server.

Attached Thumbnails

         

more photos

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Comparison of sideways wiggle is the test once used. It can be measured. comparing it to other valves and guides on the head. Not really all that scientific but a general indicator. A dial indicator should be enough.

No way as accurate as a bore gauge. But if you do not have one laying around and use it ofen enough to trust the feel.

I have a hard time getting the right feel when using machine shop measuring tools. I like a micrometer with the click stop for example. It takes away some amount of judgement call. Since I suspect you are going to have an automotive machine shop do the seats and valves. Why not let them tell you?

Even if you where to drive in a new valve guide it would have to be reamed for the valve stem and the seat machined to match the orientation of it's bore. At one time a machine shops bill was quite reasonable for this. Times have changed but some shops still might have decent rates. Ask your local mechanics who is a good and reasonable shop to use at the same time. Ask at least couple to find out one they recommend.

This of course after finding out if everything else is okay or not. Well Hunter was also right on one of his expectations . There really is a tad of carbon buildup present there.

A piston crown as hammered as your can mushroom/expand (like the top of a chisel) to the point where it will contact the cylinder wall, and then the piston will seize.
Also the piston can cracks due to the damage.
If it was my engine, I would replace that piston.

__________________

76 240 D. Bought in 1998 for $25.
85 300D. Got it for free with a bad engine. ( Sold )
60 Unimog 404. What was left of it, was given to me. Now powerd by 617A.
88 560 SEL. Bought without engine and trans. Now powerd by 617A.
67 250 SE. Cuope. For resto or sale.
64 220SE. For resto.

Two points.
#1. In your picture, that is a broken valve GUIDE, not the valve.
#2. Your cylinder is drenched in engine oil, his is fuel coked from low compression/incomplete combustion.

Yes what a dope! I meant to say guide as in girl scout XXXXX book...

__________________
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!

Army, what caused your valve guide to break? That is very unusual.

petecooke, where are you located? I have a good head from my 83 240D, still in the engine, in CT. If you don't want to fix yours, my head is an option. My engine ran good. Did 0-60 in 17 seconds, documented in videos.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

I can only guess at what happened to the guide. I assume it was due to some Mercedes "expert" from whom I bought the car adjusting valves with straight spanners. You can read all about it here

http://www.peachparts.com/shopforum/diesel-discussion/276144-om-617-manifold-oil.html

And I did find later on that the "group of three" rocker arms were positioned incorrectly on the head. (Only applicable to the OM617 of course)

OM617 rocker arm problem?

__________________
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!

As I resurrect an old thread....how was that broken valve guide diagnosed (before the obvious physical evidence was found). I still have my smoking issue and I *know* I put aggressive side pressure on the valve keeper to try to keep it from turning since I didn't have the third special tool.

I would not be surprised to find I broke the guide, but how would I diagnose that....other than pulling rocker and spring off?

__________________
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.

And now that I've invested 10 minutes in reading 4 pages of forum, what was the end result on the 240d?