G oil pressure

[FMM]

Question about the oil filtering system on the old G or U models with the old round filter element on the left side. These are a full flow filtering system I beleive so does that mean that a plugged filter element can drop oil pressure readings? It says in the manual that all oil must pass through the filter before going to the oil lines. I am having some problems and was wondering where to check. I removed the filter and turned the engine over once and oil flows freely from the verticle pipe in the bottom of the filter housing but am not getting much pressure. My local stores can't match the filter, otherwise I would just change it first. Does anyone know a NAPA or some other number that will match the origional? Thanks for any help.

 

[Bob]

IIRC, WIX 51111 = NAPA 1111

 

[Curt Cooke]

Low oil pressure is not caused by a filter problem. The first suspect is the spring and piston (regulator) that controls the oil pressure. That's adjustable by means of a screw underneath the oil filter body. If the guts of that regulator are there and operational you can increase pressure by turning the screw in. If you cannot affect the pressure then you my have a fatigued spring or a stuck and scored regulator piston. If you can get the desired pressure but lose it when things warm up, then you have other problems. As I recall, desired pressure is but 25 psi at operating temperature and rpm. If you can't get it, I would suspect too much main bearing clearance or an ineffective pump.