troubleshooting a 1991 350sdl
 

ok guys,join me in this journey,just went to michigan to retrive #93 car,now keep in mind that it probably will take me a month to get this thing apart and report all findings.
here is what i am told,car threw a serpentine belt,red lined on heat,new belt was installed and everything looked normal,car was driven 100 miles and lost oil pressure,smoked heavy out the exhaust.towed to mb dealer and got price for 8-10k engine,then towed home.
here is what i see,radiator is out of coolant,oil is full(stinks like burnt oil)engine will crank over and cranks like one with all glow plugs or injectors removed,no oil leaking from the engine. when cranking the cam shaft it turning.
i did add one gallon coolant to radiator and tried to pump pressure up on the coolant system, arm got tired and no pressure, there is coolant now leaking from the bottom center of the radiator.
ok lets take a shot at this one.
larry perkins lou ky

I cracked a 603 head. And yes it makes a horrible sound like there is zero compression and the starter is under no load. Check turbo compressor and see if coolant is in there. Depending on if/where the head is cracked the strokes will cough coolant back into turbo. (ask me how I know :eek: )

Head probably warped/cracked on first overheat, then operating heat took it the rest of the way after serpentine belt was replaced.

Given the fact that it ran after the belt replacement I would guess that the rest of the engine internals, etc. suffered much and therefore a head replacement (if that is what it is) should do the trick.

js
 

i just havent seen a head so bad that all compression is gone, course i am just listening to the starter and assuming no compression. i suppose if i had have been the owner i would have tried to restart the thing a few times and now the cyl walls have to be clear of oil and mostly diesel fuel there.
my experience with blown head gaskets was one 603.96 and it looked like old faithfull but would start right up, head was cracked and gasket was blown. second was a 92 300d 2.5 and it pumped oil out the exhaust, was a mess.
will be interesting, thanks for any suggestions
larry perkins lou ky

id keep that crankshaft from the engine if its ok (the crankshaft)...

The downside is you probably will not be able to save the head at that level of compression loss. Mine cracked around cylinder 3 and from the outside there was no leak of coolant or oil. On the inside coolant was going right into the cyclinder. There is probably sufficient warping to cause the head to leak air in several places though perhaps not oil or coolant.

I managed to pick up a complete head for $1200 from a wrecker on Long Island that was rebuildable (complete meaning cam, injectors, the whole nine yards). The first one I picked up from Potomac German was no good so I had to send that one back. There's two on car-part.com right now both off of later model meaning you'll get a good revision (better than #17..mine was a #22 off a 94 S300D)

Don't know what you paid for the ride, but if you do all the work yourself minus the machine shop, you should have something where the sum is greater than the parts.