Broken valve guide....what to do...
 

With the 240 done I finally got into the 300CD. New compression check is 305, 225, 400, 310, 305 (cold)

Checking timing chain with magnetic base dial indicator, negligible, can't even see a full degree.

Since #2 was so low, pulled rockers and half of #2 guide came out with the seal, valve is very loose, running it up and down by hand it feels bent.

Is the motor worth me pulling the head and getting repaired? Tossing on a used head??? Or should I just look for a motor?

If it's motor, anyone near Raleigh got a 617 turbo motor they wanna sell...or do I have to add that to the list for the Vstech visit? :).

If the short block is OK, replacing the head would be OK.

If you get the head repaired an oversized OD guide must be found by searching parts dimension catalogs. Also expect to replace the valve seat as it is probably hammered out of round.

All the other guides need removed and replaced as you don't know if one is cracked / ready to crack. The most direct route is to find another head, have it prepped then make the swap in one motion rather than taking apart, waiting a week or two or four then getting back in to the swing of things.

The other option would be to find another Engine and that mitght just be a new "Can of Worms".

Anyone reading this. What is the cause of the Valve Stem Guide cracking like that???

My first valve adjustment. Completely my fault. Read the DG how to so didn't realize there was a 'third' tool to hold the valve spring keeper from turning. #2 exhaust bottom nut was quite frozen to that keeper plate and I got in there with vice grips and everything else I could think of to try and keep it from turning.

Must have put too much side torque on it. Age doesn't always bring wisdom (pretty damn obvious with me). Later I got a copy of the FSM and 'ah hah'. Bought the proper tool and was able to adjust everything, but the smoking had started, and obviously it was what I did.

Probably why the 240 was such an easier resto job. I made my mistakes on the 300cd.

I have a hard time believing this was your fault....I have done many valve adjustments and have never needed the third tool.....I am really believing this issue was present before you did the adjustment....granted it may not have been completely broke but I imagine it was on its way or the valve was bent....you putting torque in it....to loosen the nut, was all it need to break at the fracture....

I was really thinking your issue was valve guide or seal related....I suppose I was thinking correctly....

Now let's look at the bright side, with a used head and hopefully you'll get it rebuilt.....you will have two very nice w123s on your hands...

As jammed as that nut was on there, you may be right about valve already being bent, but I sure didn't help it any playing gorilla. Good news is that I start a new job in two weeks that has quarterly incentive bonuses so if I do good then in 3 months I can get the CD painted....which gives me a couple of months to get a head and have it gone through. Of course wife knows about the incentive too and she's eyeing new tile for the bathroom.....

I've got two complets 85 Turbo heads, and one 83 complete low mileage turbo motor... I've also got an 83 turbo motor that needs a ton of work.

Don't want work :). With the new job startin and a long commute I'm goin for easy over cheap. I suspect time wise, swapping the motor is less hours than swapping head.

I don't think that is true.....its easy to r&r an engine but takes 2 days......and no telling what parts may get destroyed in the process.....I think my friend pulled the head off a 240d in like 2 hours.....then like someone else mentioned no telling what kind of worms you would get with the new engine......

Just read Army's how to on the motor pull, it's a bit more of a pain than the usual engine pulls I do (saabs, american, asian). OTOH the FSM on the head pull is a bit interesting as well.

I suspect this turbo head will take more than two hours, but I want to take some extra time to make sure the timing chain isn't going anywhere, cover the delivery valves and generally take the time to make sure nothing else breaks.

One thing is for sure you'll be quicker the second time you do the job!

I'm thinking you might be better off with the engine swap so long as you know it is a good running engine.

Taking stuff to pieces does come with the added danger that you find something else wrong with the block.

I had exactly the same problem with my non turbo OM617. A broken valve stem just like yours =>

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

I attribute my busted valve stem to some kipper using normal spanners when adjusting valves - the engine had suffered from a Mercedes "expert" before I bought it - rocker arm sets were installed incorrectly...

When I pulled the head off I found that the bores were pretty badly worn too and then with the added cost of getting the head repaired it turned into a full on rebuild.

After about 6 hours of wrench turning, I've discovered I can't comply with FSM requirement to pull turbocharger unit. The front lower bolt defies any angle of attack. It is disconnected from exhaust pipe so it'll be coming out with the head. Hopefully I won't have an issue with the oil return line, I think I can get it detached.

The odd compression numbers have me believing it'll end up needing a motor anyway, and the end play in this turbo is excessive, the vanes will be rubbing the bore soon.

I still need to get the odd socket for the head bolts, line up and paint the chain/sprocket. Get the guide and tensioner out.

Progress update, or, I break more parts :). finally got the turbo pushed aside, bought another flex socket that got on there, couldn't get to bottom oil line bolts but it had room to stretch.

Pin that holds upper chain guide...FSM says to use slide hammer. Saw a post on making something with a bolt and spacer so off I went. Promptly broke end off pin. Placed rags around chain guide, broke the plastic around pin, removed guide, then pried pin out as a V shape.

Just need a new guide and pin to go with my head and all. FSM says nothing about chain, I zip tied it together at the lowest point I could reach, and then hung it from a string in the overhead.

Hoping a trade deal comes through so I don't have to finish this, can't imagine reassembly going very well but who knows. The required triplesquare will be here tomorrow for rest of removal.

I am curious what you can get that guide pin for....I had the dealer price out a new one last year and they wanted over $75.00 for it and it had to come from Germany. We had a broken exh. guide on #2 cyl. Wagon head. had no choice. Swapping motor= way easier.

I'm thinking the motor swap would have been easier. I got all the guide pins and guides used for $30. I'm still lookin at either pickin up a motor from VS or buying a driving car locally and taking the engine and other bits.

If I could find someone to do the engine swap I'd pay for it but I dunno any pro wrenches in NC :(.