PeachParts Mercedes-Benz Forum - View Single Post - om617 952 idle wobble, compression test results, oil in coolant

Diseasel300 · #4 09-25-2017, 11:09 AM

As said above, the head gasket does need changing. Oil in coolant (or vice versa) is not a good thing. You'll need to do a thorough flush of the cooling system to get rid of the oil contamination as well (don't skip this!).

Compression testing on the OM617 is iffy if you haven't done the valve adjustment first. The valve seats and faces tend to wear and then the valves get tight against the cam causing compression leaks. If you have a blown head gasket, the compression will often be low due to compression leakage through the head gasket breach.

If I were in your shoes, I'd do exactly what I did with my OM603's head. Take it to a machine shop, have it inspected for cracks, warpage, etc and have them machine the valves and replace valve guides. When you get it back, it'll be like a new head.

The bottom end of these engines tends to be very strong, most of their issues happen in the heads and are relatively easily solved. Unless you were blowing big smoke, having great difficulty starting, or have large amounts of blowby gasses coming out the valve cover, I wouldn't worry too much about the bottom end.