On the way back from a working trip to Florida, My engine suddenly sounded odd -- much louder, and much less power. Pulled over, nothing looked bad, still full of oil. Continued on -- would still get up to cruising speed, and the noise got no worse. Got home very late Sunday, tried to slide thru the week (no other transport to work) so I could explore Saturday. The engine lost more power Thursday, but sounded the same. Friday it died running at low speed, just quietly shut off.

Pulled the valve cover off -- the front cam tower is broken on both sides, and the cam is broken - the chunk to operate #2 cyl was cleanly broken off & lying there as a separate piece. The cam is now in 3 pieces.

The chain & sprocket look OK, though I have not yet tried to turn the engine to make sure the chain is not broken.

Can I just replace the cam, bearings, & towers and have a chance at a running engine, or is there more going on here (like a blown head gasket to start with)? I'm still trying to figure out why the engine would run, sounded much louder & bucket-of bolts-like, but still got me home without the sound getting worse. Would it do that if the cam broke & I lost the #2 cylinder? There is no water visible in the oil, and I could not feel any compression leaking out the side of the head at idle when it was still running.

My ability to work on this is limited, as I live in an apt at the moment.

Thanks for any help.

Ed

You had chain problems. The broken cam probably could have been avoided entirely if you had stopped the engine and towed it back when the noise started.

Check the chain tensioner and rails for damage.

At the least look into replacing the cam, all the cam towers, chain, and slider rails. If you have bent valves then the head has to come off.
It would be quicker and more realistic for an apartment dweller to look for a used engine to swap rather than repairing one with a broken cam.

If you decide to part it out, sell it or junk it, keep me in mind for that 5-speed transmission.

It sounds like you jumped timing, perhaps one tooth at first, losing power, then when it jumped another tooth you had valves hitting the pistons and breaking the cam. I don't actually know if you can jump one tooth and nothit valves so the first part of the problem could be something else.

Broken cam definately means cam timing off, a bad tensioner or a broken cam chain. There could be other causes too.

So as FI noted, you need to check everything to determine exactly what is damaged and make no assumptions before turning it over and possibly bending more valves or breaking your new cam.

If you are unsure of any of this you may need to get an expereinced Mercedes Diesel mechanic to come look at it with you.

Good luck.

Tom W

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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.

With thumb and forefinger, try to lift a link or two of the timing chain up off of the camshaft sprocket. If the chain will lift up more than the tiniest fraction of an inch, it has stretched/worn. You can do this even if the chain tensioner has the chain nice and tight. Also look at the sprocket, see if it is worn. That would explain why the chain has jumped a tooth (or teeth). How many miles on this car/engine/chain?

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

... 5 speed?
ya wanna trade an entire running car for it?

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thanks, everyone, for the good suggestions.

I will try them all out. I think I have found a good candidate to check the engine out -- someone with more room, tools, and experience.

If I decide to let it go, youse guys will know first.

The engine has about 255K, I assume chain is original.
It did run a little hot after the first change in performance, maybe 10 degrees steady. It blew a steady cloud of black smoke - not usual for this car.