Fitts07, if the PO had this vehicle serviced at a MB dealer then their recommended maintenance was ignored ... likely to save money. No MB Service Department would use other than MB coolant (now blue, instead of the previous amber color), nor would they ignore weeping freeze plug. It's likely the timing chain cover is leaking oil which coats the front of the engine and the oil pan. If the engine isn't burning oil outright, the burning oil smell is due to leaking oil on the hot engine. It's likely that new valve stem seals are needed. As you mentioned in your first post the engine likely needs new fuel injectors. Very few owners are selling well-maintained vehicles with absolutely no problems. A pending major repair encourages a sale. Check a local salvage yard for a sound encapsulation panel that belongs under the engine compartment. The former one was probably a mess from dripping oil and the PO tossed it. Recommend buying a rebuilt water pump from your local MB dealer.

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Fred Hoelzle