300D in yard with dead cylinder

[engatwork]

Beautiful original owner 307k mile '85 300D in the yard with a dead cylinder. Will get the head off over the next few days to see what happened. Hopefully, it is just a cylinder head or gasket issue. Blows the wrong color smoke on start up.

[Ken300D]

Well, the "wrong" color could be white, cloudy smoke or thick blue clouds. Since you mention the head gasket first I'm guessing you've got white smoke. I hope it is only the head gasket. Is it your car or a repair job for someone else?

Ken300D

[engatwork]

It is white smoke.
It is a "customer" car out of North Carolina. It was brought down on a trailer. Really good looking car in/out. It has one of the very few blue dashes that I have seen that does not have any cracks in it. Even if it takes an engine rebuild the car looks like it is worth it.

[mespe]

Whatever might be wrong with it (head, valve, piston etc) I probably can get you the part really cheap, as I've torn apart a M617 engine and have the parts handy.

Marty

[1983/300CD]

How much is involved in changing a head gasket in a 617?

I'm about to change out my valve stem seals because of a white/blue smoke issue, but I suspect that the head gasket might be bad too. I will do a compression test tonight to see if I have a low cylinder which would further point to a bad gasket.

Just wondering if I can do the head gasket myself or if I should let a professional do it. It's just that there is nobody around that I would trust to do it. I can screw up just as bad as the locals can.

[dieseldiehard]

Originally Posted by 1983/300CD

How much is involved in changing a head gasket in a 617?

I'm about to change out my valve stem seals because of a white/blue smoke issue, but I suspect that the head gasket might be bad too. I will do a compression test tonight to see if I have a low cylinder which would further point to a bad gasket.

Just wondering if I can do the head gasket myself or if I should let a professional do it. It's just that there is nobody around that I would trust to do it. I can screw up just as bad as the locals can.

a 617 head gasket job is not too difficult, the head is a heavy thing to hoist in and out.
You may want to use a new timing chain if yours is the original.
If the smoke is blue and smells of burning oil, check to see if the vac pump diaphragm is allowing oil back into the intake manifold, that has been known to be the reason for burning oil and is obviously much easier and cheaper than a head gasket.
If the white exhaust is sweet smelling Glycol stuff then its probably a head gasket. As long as you remove the head to replace the gasket its worth having the head checked for cracks and flatness as well as a skim cut to assure its flat as wells as new guides and seals.

[dieseldiehard]

Originally Posted by engatwork

It is white smoke.
It is a "customer" car out of North Carolina. It was brought down on a trailer. Really good looking car in/out. It has one of the very few blue dashes that I have seen that does not have any cracks in it. Even if it takes an engine rebuild the car looks like it is worth it.

Nice! I think the '85s are the best of the 617 turbodiesels and worth keeping running especially if in nice shape.
A car with a dash that hasn't cracked a lot is indicative it was garaged so hopefully the paint on it hasn't weathered like it did on my '85 300TD. MB switched to a different type of application or material in 84/85 and many cars lost clearcoat in a hurry.
Check the vac pump, I had mine start making a clicking sound (like the 603's they can ruin the engine if they come apart)

[engatwork]

Started getting into it this afternoon. Should have the head off by this time tomorrow. I've got the fuel injectors and glow plugs out. Only thing that looks not right is the #5 cylinder hole where the fuel injector screws in. There is oil in there that is not in the others.

[engatwork]

Got the head off this evening and found the gasket had a bad section in it on the #5 cyl. Plans are to strip the head down and have the local diesel machine shop go through it while it is off. For 307k miles the tops of the pistons and cylinder walls look good and the chain is only showing around 3 degrees of stretch doing it the quick and simple way.

[blueranger]

at 307 not only would i have the head reworked... but I would also replace the rings... and if its a 617 you might also replace the sleves....

[dieseldiehard]

glad to hear its just the headgasket. A rebuilt head will perk up the car I'm sure.

I would agree with new rings at the least and Deves are great. If there is still crosshatch on the cyl walls your probably OK to go without new liners. The PO must have performed regular oil changes

[engatwork]

Probably a good idea. I will get in touch with the owner and see where he wants to go with it. Heck, with the head off pulling the engine/tranny is a piece of cake.

[t walgamuth]

good chance getting into the bottom end is not needed.

did you do a compression test before taking the head off?

on the turbo motors, the head gaskets seem to go around 275 to 300k.

tom w

[engatwork]

The ring land on the #5 piston is trashed. If you look real closely you can see where the moving ring material has kinda eaten away at the ring land section. Thankfully the other pistons look good.

Note all the missing ring land section shown on the pic on the left. There is a big chunk of it missing. The rings were broken on this piston.

[engatwork]

In tearing down this engine I confirmed what I have been suspecting for awhile. The chain guide rail that seems to wear the most is the one for the oil pump chain. This car is at 307k miles and it was definitely time for new guides/bearings.