80,000 miles is not that much for a M127 engine. Maybe it just needs some head work or something else less drastic than a full rebuild. Having an experienced mechanic who can properly diagnose the engine is important. You can inquire at Metric Motors for rebuild work (see
www.mercedesengines.net and
http://www.mercedesengines.net/200s.htm - found here:
http://www.sl113.org/data/show_table.asp?table_name=usr_parts_and_service_suppliers.
For a long block rebuild you will note a price of $5,700 and an 18-month warranty. To that you will have to add shipping cost and the cost of pulling and re-installing the engine (figure about a day each) plus I imagine the usual extras like fluids etc. and maybe when the engine is out, you will want things like subframe, engine and transmission mounts replaced, have the engine compartment cleaned up etc.
I think there is a real advantage to using a shop that is specialized in these period engines. As Dan Caron points out in another of today's active posts, there are so many little things to watch out for that many mechanics not familiar with these engines may gloss over, which can be costly down the road (literally!).
Good luck! At the rate your car has been racking up miles, a rebuild should last you another 80 years!
Cees Klumper in Amsterdam
'69 white 280 SL automatic
