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!

Head's off..

I'm happy. Pistons look pretty good, cylinders show no signs of wear. As in, I can still see honing marks in the cylinders.

Intake looked pretty clogged.. lots of crud, particularly at the end of the manifold around #5.

Pictures in the morning, then the head goes to the shop Monday.

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'82 300SD 351k

Are you deliberately avoiding any statement about visible evidence of valve problems?

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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

Not particularly - my wife called me late for dinner as I was posting that.

It was about an hour after sunset by the time I got the head off, but I did get the valves out of #5.

Exhaust valve looked ok, but there was thick carbon all around the back side of the intake valve. I'll post up pictures in the morning, my camera does very poorly in low light.

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'82 300SD 351k

Sounds like a tight valve.

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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.

Pictures are up, full gallery is on picasa here:
Benz Head Removal

So, I've never seen a burnt exhaust valve, but I don't think this valve was burnt.



The intake valve, however.. had some large chunks of carbon which fell out when I removed it.

Hard to see in the pictures, but cylinders #2 & 3 still showed honing marks. I couldn't figure out a way to safely rotate the engine off TDC, so all I can see is the top third of the #5 cylinder, and none of #1. But I've seen scored cylinders, and these look pretty good.

I haven't a lot of experience with internal engine work. The only other time I had a head off a 617 was on a motor with a blown piston (#5 coincidently) that I was breaking up for pieces.

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'82 300SD 351k

I'm thinking there may have been a possible head gasket leak to the oil gallery.

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'82 300SD 351k

You're right. Something looks awry with the headgasket. Not sure how that would have shown up in a leakdown test.

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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

Pic 13, looks like it has been blowing at 6 o clock and 7 o clock

Pic 17, looks like liner damage at 12 o clock and 1 o clock, corresponds to above.. liner also appears to be low in the deck around 9.10.11 o clock

while it's off, mic all the bores (mid stroke, across the block and again along it) and do a measure oil soak test on all the bores, eg measured about of atf and time it, each piston in the same height in the bore.

pics aren't good enough to pick up glazing / polishing in the bores..

edit, one of the pictures also show what appears to be stick **** on the deck to beef up the head gasket around the liner problem, which means the PO was aware of this, possibly a badly fitted liner, tried to get away with it.... BUT, this is subjective, notoriously hard to tell from a pic.

#5 exhaust seat is also a goner.

Note: This engine has been in the family for 20 years - I'm pretty sure the last time this head gasket saw daylight was in Stuttgart. I have history going back to the dealer and there's no indication of anything more than valve adjustments and minor repairs.


Any suggestions about rotating the engine without dropping the timing chain?

An oil soak test is going to take all night. #5 still had oil in it from me mucking around with it last weekend.

Just finished cleaning up the block - it's wiped down with oil now too.

The head is going to get hot tanked then fully rebuilt by Metric Diesels, starting Monday. I'm going to ask them to do some kind of NDT on it, either dye penetrant or mag flux.

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'82 300SD 351k

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.

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

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.