Gsxr:

I went over to the get some miscellaneous parts for my engine at the machine shop/ engine rebuilder, and he showed me a brand new 603 cylinder head casting. It truly was in need of some rework. The bottom surface was not smooth the way it should be when it is surfaced properly. Instead, you could see & feel (!) the rough surface left by what appears to be a fly-cutting process from the factory. There were other rough areas as well - this can be a stress riser leading to cracking in the future. I couldn’t tell by looking at it, but I was told that they usually re-do the valve seats as well. All in all, not very impressive. It is obvious that whoever is doing the castings for MBZ is not using the same QC standards as MBZ used to have. Sad. Very Sad.

It would seem to be a prudent move on your part to have someone that is *really* knowledgeable about the particulars of these engines do the machine work for you. Using the head casting ‘as is’ does not seem like a good idea at all.


Dieselnation:

You may want to use the ‘search’ function (type my name in) to look at prior posts that I have made regarding the problems.

To answer your specific questions:
1. Fuel mileage was usually around 23-24 mpg when I first got the car, dropping down to around 22 as time went on. I have a heavy right foot.
2. I’m not sure about the nailing or thudding, as I don’t have a valid point of reference – this is my first diesel, so I don’t have anything to compare it to.
3. Morning starts became rough, with misfiring for 5-10 seconds, even with extended glow periods. Note that the coldest it’s been is in the 40’s (up until just the last week, at least). Strangely enough it was HOT starts that gave me the most problems, with extended cranking needed & then a cloud of gray smoke from partially burned fuel (not steam, as the cloud did not readily dissipate).
4. Affect performance? Again, I have no point of reference as to what a properly running diesel should be like.

Thanks again guys…

RTH