I changed to 5W-40 synthetic and am now leaking from what appears to be rear main seal. For the sake of my question, let's assume it is (and is not the oil filter to block housing or cooler lines) and assume I take the engine out to fix it. BESIDES the items listed in the transplant guide, are there any "may as well do's" while the engine that has 190Kmiles is out anyway? Compression is 320/320/310/290/300psi COLD and oil pressure at 1.75 bar at 85 degrees C after a hard highway run....is a ring job/crankshaft bearing "cheap rebuild" worth it with those numbers?
I did a "may as well do" rebuild of crankshaft bearings, rings (no oversize), cylinder honing and timing chain on my '77 BMW and escaped w/only $200 worth of parts after it blew its head gasket. (It's compression was 140psi [low end for that gasser], burned 1qt/700mi and very low oil pressure, less than .25 bar, now over 190psi, burns none and oil pressure restored w/o a new pump. Crank bearings were worn to copper due to fuel in oil.)
This is totally hypothetical...when I change to 15w-40 in spring and it stops leaking, it may be a moot point but I, and possibly others, want to know what to do with an existing "good engine" while it's out anyway should I choose that path.
Thanks.