Question about an engine that's got extremely low oil pressure. It's a 1987 TBI 350, and I've run a can of Seafoam through the oil, tried different weight oils, but I still have the same problem. At hot idle, it sits at about 6psi, and at hot cruising, at 23-24psi. It's around 40 on a cold start, but just nosedives after that. When I'm driving, as soon as I take my foot off the gas, the pressure drops immediately down to 6-7psi.

Short of a full rebuild, is there anything I can do to try and get the pressure back to at least a decent level?

 

new oil pump

 

That's not exactly a 10 minute job.

 

If my memory serves me correctly it's a hell of alot easier doing it on your truck than a 99-up. I know it for damn sure couldn't be any worse.

 

Have you checked it with a mechanical guage, are you sure it's not just a bad guage or sender? If so, I'd suspect either an oil pump/pickup problem or a worn engine.

 

What's involved in doing it?

 

The engine's only got about 87,000 miles on it, but going by the state it was in when I bought it, it very well could just be tired. It'll be rebuilt in 2 months or so, just wanted to try and get the pressure up a bit until then, so it doesn't decide to spin a bearing or something.

Haven't used a mechanical gauge, and the dash gauge currently doesn't work (guy decided to hook up LED gauges and he "disabled" the dash ones, evidently), so the number could be off. I'd almost suspect it is off some, because I've never known of an engine running very long at a 3psi oil pressure at hot idle.

 

Well a Cummins is good with 7psi at idle so as long as you motor is just worn out than you should be ok for a few months. If you pressure was fluctuating high and low then I would be worried. As long as its constant just put in some Royal Purple 20/50 to fill in the bearing gaps you have and let that 400% stronger film strength do its work the next few months. I ran my silverado for months with a spun cam bearing and very low oil pressure and it never quit. Then again I didnt give a **** if it blew because I had other plans for it. lol

 

If it changes pressure based on you being on the gas or not, it sounds like it might be the crank shifting, possibly a bad thrust bearing? That's what my 6.0 did when the thrust bearing was on it's way out, except opposite. When I would roll into the throttle oil pressure would drop, and when I let off it would come back up.