Posted by Alan Bowes on March 07, 1998 at 10:27:40:
In Reply to: synthetic oil posted by Pete Vernon on March 06, 1998 at 21:10:26:
Hi,
While it is true that worn cam bearings could lower your idle oil pressure, worn main or con rod bearings are a more common cause of low oil pressure. Also keep in mind that as Steve mentioned, oil pressure gauges are seldom very accurate, especially at low pressures. Also as Steve mentioned, a worn oil pump could be a cause.
However, there should be a noticeable increase in hot idle oil pressure if you switch to synthetic oil. I have seen it happen on every vehicle on which I've switched to a synthetic oil. This includes new cars as well as high-mileage vehicles. There have been some other discussion threads on this topic. You might want to read through this forum as well as the archives.
Another factor is idle speed. Is it set to specs?
Can you hear any bearing knocks at idle? Any thudding when heavily lugging the engine? Any clattering sounds when lightly accelerating? These could be symptoms of worn main or con rod bearings.
Alan