Cleaned up for the night.. here's the last new information for the weekend before I hear back from the head rebuilder.

I cleaned up the block some more - the liners all sit flush, no edge that would catch a pin could be felt.

Tried the ATF test.. 4 oz of ATF in each cylinder doesn't seem to be draining through (it's ~60 F outside, and cylinders are still sitting with #1 at TDC)

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'82 300SD 351k

You've got me very curious...

How do you deal with the timing chain / cam sprocket when removing the head of a 617? Is there a way to keep the chain on the IP? Do you carefully keep tension on the chain and feed it through the head as it's removed?

I heard that should the chain slip from the IP, essentially you have to pull the engine to set the timing right once more.

I am going through the same issue with my - new to me - 1980 300SD, with only 165,000. I did a compression check and found the #1 cylinder 100# low. Followed up with a quick leak down test and could hear air going out of the exhaust pipe. I turned the car over to the mechanic who does the stuff i don't feel up to snuff on. His comment was the same "rings or valves, the head needs to come off." He said you can do the rings from underneath without pulling the engine. But either way, the head has to come off.

Looks like i diagnosed correctly. He reported back today the exhaust port on #1 leaks badly. So off to the machine shop it goes. Who knows why it happened with such low miles and lots of service records.

I word to the future MB buyer, compression check, compression check, compression check!!!

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1985 300D, 250k
1980 300SD, 180K

Sure you can do the rings from below without pullng the engine....if you torch out the cross member.

Actually you cannot even pull the rods from below with the motor out of the car....I am pretty sure about that.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

why would you try to pull them down?

You drop the sump, pop the cap off the conrod and slide the whole thing up through the block, that is what matey's mechanic was talking about...

offhand I can't think of a single car engine you could get the pistons past the crank if you tried to pull rods from below...

I don't know what you guys are babbling on about but this is easily the post of the year!!!!!!!!

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

If you look carefully at the timing chain, you can see the piece of wire holding tension on it. I got a friend to work the engine hoist while I carefully fed the chain through the head then tied it off.



This is why I didn't want to rotate the engine off TDC if possible.. with only two hands, I'm afraid of dropping that chain down in the block.

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'82 300SD 351k

Someone made a mistake when adjusting the valves? Why did you do the compression check? Was it missing or running poorly?

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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

If sure he didn't mean that you can take the pistons out the bottom!

I agree it would be pretty foolish to try to do rings with the motor in the car. I think the head is about as much as you can remove before it makes more sense to pull the motor and work on a stand.

As it is, a head R&R is basically two steps:
1. Open hood.
2. Remove everything you can see.

I'm half wishing I had pulled the motor. Probably would have been only another 2 hrs more work.

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'82 300SD 351k

I learned, well after I did the head on the 617, that all the talk about holding tension on the chain so it won't fall off the IP and crank sprockets is just total fallacy.

One of the members here who knows way more than I do simply drops the chain down the abyss to China. He does the head rework and fishes the chain back up when he's done. No issues with the chain becoming disengaged from either sprocket.

Why not? I can understand the IP because it would rest on top of the sprocket, but why wouldn't it fall away from the bottom of the bottom sprocket?

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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

Apparently not..........but, I'm just the messenger on this one. I do have very high confidence in the source.

That makes me much less scared of dropping the chain, but I think I'm still going to check mechanical timing before I close it up.

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'82 300SD 351k

I would just take a metal coat hanger, wrap one end around the chain and leave the other end hanging over the engine... The alternative is to bungy cord it up (hood?)

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42