22re off and on motor knock

[Souzy Souza]

So I just got a brand new Toyota(for me). It's an 1987 with 98k on the original motor. I'm trying to diagnose what's really causing my motor knock. It's off and on. When I accelerate it goes away but whenever I'm not it rattles a lil. Where should my oil pressure be at? I'm thinking it is a oil pump going bad. My oil pressure gauge never goes above a quarter.
I don't want to start tossing a bunch of money at the wrong things. I know these motors can take a beating but has anybody else experienced this problem with their old pickups? Any insight would be great.

 

[tbplus10]

First step should be to hook a mechanical oil pressure gauge to the system.
At idle if I remember correctly Toyota says anything above 18psi is good.
Also check the oil filter, some of the anti leakdown filters cause issues on these engines.
Whats your outside temps right now and what viscosity oil are you using?
I have seen the pump pick up and pump seals go on high mileage 22r engines, yours is low mileage but age may be the cause if its failing.
A replacemen oil pump is cheap enough, just a bit of a pain to drop the pan and replace.

 

[Souzy Souza]

I like the mechanical oil pressure reader. Thanks for that tip. I'm running 1030 currently. I'm thinking there's a clogged oil passage that's not letting the oil circulate like it should be. Oil filler tube or sending unit possibly. Im still gonna see how my oil pressure is doing thanks again and I'll probably just drop the pan and see if I see anything gunked up. Thanks mate.