Re: Broke down.

Posted by BH On 2008/9/21 10:15:33

mikec -

It's difficult to describe a sound with words, but if it's coming from a single lifter, I suspect it would be making noise at half the rate of the engine RPM. Bottom end noise would be at the same rate as the RPM (faster), but rod bearing noise can be twice that (because of the up-down stroke).

I'm no master motor builder, but I've found that when these cars have spent a long time (years/decades) unused, they will exhibit some lifter noise that can be cleared up after a couple of oil changes, each with a dose of STP. That hints at a build up of varnish in the lifters.

If you are concerned for catastrophic failure, you should remove and inspect the lifters. Then, drop and clean the oil pan (and pump strainer) and check the main and rod bearing clearances. Report back with your findings.

Yet, if you have good oil pressure, I doubt if those bearings are the issue.