As a former marine repair shop owner, I recall one MerCruiser
sterndrive engine model that had a hard-to-figure head gasket
failure symptom.
The engine was a 4-cyl aluminum block, with a cast iron Ford 460
head. When a customer came in talking about coolant loss
through the overflow into the reservoir, in foamy surges (after
a high speed run), it indicates a faulty head gasket. The service
manual said that it could not be detected with a cooling system
pressure test or compression test, and it would not show up at
low speed.
I recall some customers who had been through a lot of things in
their attempts to fix the problem, and had trouble accepting our
diagnosis. Some people had already spent money elsewhere
without getting a successful repair job. At least once I let the
customer go run it afterwards himself to verify the repair before
paying.
Carl Wade
B395000858 LRX
|