Low oil Presure - Replacing Bearings


#1

I posted about a month ago. 1997 F150, V6, 4.2L, 136K miles. Low oil pressure (confirmed) at idle speed. Every thing points to bad bearings. Is this something that can be fixed or prolonged by dropping the oil pan and replacing the bearings ? I was under the impression that I’d need to do more than that ??


#2

“Dropping the pan and replacing the bearings” is much, much, easier said than done. This is a MAJOR repair that has about 15 different ways to get sideways… It seldom goes like the book says…

I would drive it until you can HEAR a rod knocking, then scrap the vehicle or replace the entire engine with a factory long block or a low-mileage salvage yard engine…


#3

Are there any other symptoms such as knocking, smoking, oil consumption, or does it just read low oil pressure at idle? If that’s all you have, it probably is worn bearings, which, by the way, would include cam bearings. Replacing your main and rod bearings may improve your oil pressure at idle, or replacing them could cause other, more major problems if your journals are excessively worn or out of round. The latter could cause your new bearings to spin. Quite frankly, if it were my vehicle, and low oil pressure at idle is the only symptom, I would just keep on driving it, keep on checking the oil, keep the oil changed regularly, and try to ignore the condition until it shows more dire signs. It may very well run for years like that and never get worse. If it bothers you that much, and the truck is worth it, just replace the engine with a rebuilt one. Trying to repair that problem would likely be an exercise in futility, and could even make things worse. Much worse.