PeachParts Mercedes-Benz Forum - View Single Post - Thoughts On Overhauling 200D (OM621) Engine

Squiggle Dog · #12 02-26-2011, 07:21 PM

Today I took off the valve cover to look at the cam and timing chain. I lined up the factory notch marks on the cam and then looked down at the pointer on the crank pulley. It read about 6 degrees BTDC. I turned the crank around again and double checked. It is suprisingly easy to turn the engine with a a 27mm socket on the crank pulley. I could hear a whoosh coming from each valve as I turned the engine.

When the #1 piston is at 6 degrees BTDC the marks on the cam line up. I thought that when the cam marks were lined up the pointer on the crank pulley was supposed to point to an ATDC reading? Does this mean the timing chain is off one tooth? You can also see the extra notches marked in the cam.

I noticed that the cam lobes are scored and have flat spots. The valve cover breather elbow and tube were also full of oil and lots of oil leaks out of them and drips onto the manifolds.

When I had it back together I decided to start the engine and then take off the filler cap to see if I had blowby smoke coming out. As soon as I took off the cap it popped off and the engine started squirting out oil all over the place. The oil shot out on my face and the fenders of the car and started shooting out at high pressure from where the oil filler cap used to be so I quickly put it back in place. Is it supposed to squirt out oil from the filler cap hole in the valve cover like a geyser?

I haven't checked compression because I haven't been able to get the compression tester fittings in there with the heater pipes and injection pump in the way.