Well, I want to really thank you guys for your help. I can't be happy about the cost to repair this problem, but I was sure I had a serious problem based on what was happening. My concern now is getting it about 10 miles from here to the shop to get the work started. It should be OK unless I bend a rod starting it!

At any rate, as I work through this, it could be that the Timing Chain replacement at 120,000 might have caused this development.
Long shot, but the numbskull that did the change@ 70K bent the valves developing into a top end repair and machining on the Head. We parted company after that and referring to my stupidity in previous posts, I'm wondering if the torque was checked on any subsequent repairs. Could be that it was and over time we have arrived here. Maybe not and that ultimately put me here. Also an overheat, but have never really experienced any overheating in the last 70K. I worked in DC and my commute was 120 miles per day until 2 years ago. Ergo 70K. All I 95 expressway if you can call it an Expressway.

Matters not. Gotta get it done and hope for the best. I guess its not how it happened but what you do about it after the fact. I've always wanted to know WHY. Guess its best to just let some things lie!

I guess my last question would be... after this job is complete, what should I look for and what would be recommended for follow up maintenance.

That question probably can't be answered until we know the extent of the damage. I'll keep you all posted!

Again, thanks. Special Thanks to Dpetryk. I'll never repay this sight for the help I have received over the years! I can always count on the folks @ Mercedes Shop.com

God bless all of you!

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1988 560SL
Black Pearl/Palamino