I posted 5-6 weeks ago with a sudden loss of power on my '89 740 GL.
The car still ran but sounded like some thing mechanical was amiss - like valves clacking that was not present at idle but rather loud with the engine rpm increased even in park and worse as the car warmed up.

The car did not overheat and there was no evidence of antifreeze in the oil.

Compression tested only ~25# on cylinders 1 and 2.

The head gasket failed in between cylinders 1 and 2 where the gasket is about 3/8" wide. Bought a new Elrig head gasket kit from FCP Groton and had it professionally installed for $500 labor. Also took the head to a machine shop and had it pressure tested - ok, resurfaced 8/1000, cleaned, intake valves ground and exhaust valves reseated or slightly cleaned up = lapped for an additional $200.

So for $750 the old tank has a new top end at 140K and runs fine again.

What I still don't understand is the sound the engine was making after the failure happened. Why did it make a mechanical sound that got louder with increase rpm at idle. Was that valve noise from the cylinders that had no compression??

Any ideas??

Thanks for all the help!!

The old brick lives rust free in Maui

maui Paul