Low Oil Pressure 2.25

[rbbailey]

Been driving this car, realizing that ignoring the problem is stupid. In doing so, I'm realizing that there really is a problem.

Oil is nice and full, running 20w50, if I remember right. When normal, it runs at about 40 psi, drops to 18 or so at idle. But after driving to full warm up, it drops to 10 or less, and no more than 38 while driving. The PSI indicator light actually came on at idle today.

I put this engine in last year because my last one lost oil pressure in same way, died.... one week after having put two years of work into it. I could see nothing wrong with the oil pump. But this engine pulls oil up into the rocker shaft area very well, so...

I'm going to pull the pan and check the screen. Nothing there, I will pull the pump. What else should I look for?

[chilidavid]

I was waiting to see if anyone replied to your questions. I'm not so good at engine issues, if that's what it ends up being.

I'm curious as to what kind of OP gauge you're running: Electrical, with a sending unit attached to your oil filter housing; or a mechanical gauge, with a direct oil line from the oil filter housing to the gauge?

NOTE: It only takes 8 lbs. of oil pressure to keep your OP light OFF. And that's pretty low. Also, the Blue Bible (Haynes Manual) states that you should not be alarmed if the OP light comes on at idle, and a normal idle can be as low as 650 rpms. But be VERY SCARED if the light comes on while driving at highway speeds!

My second electrical OP gauge (before the sender went out) read differently than the mechanical gauge I now have installed. My bet is that you are running an electrical gauge and that the sender is messing with you.

Also: My first and original OP gauge (electrical also) had something wrong with the needle. The needle would not go beyond, say, 20 lbs. or so, because something inside the gauge was getting in the way of its travel.

Good luck working it out. Sounds "electrically suspicious" to me! I hope I'm right!

David

[Les Parker]

To second the above post, I would suggest getting a calibrated oil pressure gauge and duoble check the one you have fitted.
Most autoparts stores have these for sale, I believe the thread pitch is 1/8" BSP.