I have a 1976 vette with about 120K miles on it.
Last year I had to do a fair amount of work on it (spring, shocks, rad support bracket, new rad, new water pump.).
It seems to have been developing a problem and I am not sure what it is.
I thought it started about the time I installed the new water pump, but that could be nothing more than sheer coincidence. It was making a sort of slight rubbing/banging/knocking noise, and I thought it was some minor machining discrepency causing a slight rubbing of the water and main pulleys. There was a rubbing sound that went away after a bit.
Yesterday I had to replace a motor mount and tightened a bit of exhaust on the manifold.
Today the noise is back. But now It sounds morelike a banging/knocking sound. The frequency increases with engine RPM. If I bring the engine up to a modest rpm and hold it there , it seems to go away. It seems worse when I first start it.
Now I am obviously not expecting a thorough diagnostic from this description, but I am not a very experienced mechanic. Does it sounds like the symptoms of a main/crank bearing or something terminal of that nature? If so, I'm afraid old Betsy is doomed because I do not have the facilities nor the resources to get it repaired ......
FWIW, it still seems to run ok, oil pressure is normal, battery charging, water temp, shifting etc.... I went around it with a crowbar and using it on my ear as a poor man's stethoscope and was unable to pinpoint the source of the problem (so far)... It definitely seems to be coming from the bottom part of the front/engine somewhere.....
Thanks for any input.