PeachParts Mercedes-Benz Forum - View Single Post

Jeremy5848 · #9 10-09-2011, 08:24 PM

OK, misunderstood what you meant by "adjustment." Your compression and leakdown tests are pointing you in the right direction. I don't believe there is anything to adjust as on your airplane engines. If the 606 is similar to the 603 in this respect (and I am not sure) then there is a range over which the hydraulic element in the valve cap will compensate, after which you have to rebuild the head. Do you know if others have done work on the head in the past?

In the 60x engines, the cam sits over the follower, which presses down on the valve stem to open the valve. A hydraulic element in the follower takes up the slack and keeps everything tight. The 606 has two cams while the 603 has only one but I think the mechanism is the same. Burned valves and/or valve seats would be my first guess based upon your tests. I have not heard of valve problems being "common" with this engine; it certainly has not been discussed frequently on this forum or I would have seen it. My 606 has only 280,000 miles but it is as tight as new or so it seems although I have not had the head off.

The factory published a DVD on the W210 cars that included the OM606 engine. It is no longer offered but should be available used somewhere. The OM606 engine in the 1995 E300D is very similar (you still haven't told us the year of the car). The factory offered a 2-CD manual for the W124 including the OM606 engine. It also is no longer available new but again should be available used and maybe even on-line somewhere.

One thing I just learned is that Mercedes no longer recommends use of a magnet to lift the cam followers out because the followers tend to become magnetized and they attract tiny iron particles that damage the cam and follower. Instead, they now recommend a suction cup.

Based on the miles on this engine, I recommend pulling the head and having a valve job done (or doing it yourself if you have the necessary tools). Try Books4cars.com for either the 124 or 210 manual. Even a Haynes manual is better than nothing.

Jeremy