year old engine... low oil pressure.

This is so depressing... i have a engine that is about a year old, and im losing pressure. at start up, i was getting 50, then as it heated, it cruised at 45ish, and at idle it was at about 25psi.

I replaced the relief spring, which was pretty worn, and raised the cool pressure to 65-75, but once hot and idling, back to 25 psi.

i noticed, it goes up sharply at about 2000 rpm, then drops back to the standard pressure, and raises back up with the rpm's.

so, im hoping this can be the oil pump. or anything else thats not bearings, as bearings are the last straw.

can anyone help me?

I'm no expert here, but I don't think you have a problem.
Attached is the page from the Owners Manual.
Chris

I think 25 idle is fine. IIRC, that's the spec.

My MG mechanic says 50 psi at idle as a benchmark for a good engine. Most that I have seen have been 50 at idle, 70 at road speed. Maybe you should check that the guage is reading correctly before doing anything else. FB

What brand of oil filter are you using? Weight of oil?

After you do the oil filter (PureOne) check/replacement as Kimberly notes and stick in some 20-50 Castrol and check the actual pressure with a known good mechanical gauge you might start looking for a mechanical problem. I am not so much concerned about the idle pressure as I am about the pressure at full tilt. I used to be a believer in the necessity of a full 75PSI at speed under all but the hottest conditions but now I feel comfortable with anything over 65 hot with significant fluctuation as the revs change. This holds true especially with cars not equipped with oil coolers.

The first place I would start looking is in the rocker arm/shaft/bushing department. It is probably the easiest to get to and certainly not as expensive to deal with as going into the bottom end.

Jack

Did you change the oil pressure spring with the engine in the car? That had to be a bugger. More info on filter and oil please. The numbers after the spring change sound good.

Year old engine with worn spring? What are the specs of the rebuild?

Ok, i run a K&N filter (the same huge one that moss sells, i cant remeber the P/N) and Castrol 20-50.

I replaced the spring at rebuild, and heard from... someone on this site that the springs are not tempered correctly. Apperently they are not. i have the numbers at work, but i used the spring tester there, and the old (1 year old) spring was a good 5 lbs short of the new regular tension spring. i also bought a uprated just to see the diffrence, they are a coupla lbs harder then the std spring as well...

Doin that spring isnt that hard really... buti have tubular headers and a webber that keeps mostly outta the way.


Now, Jack, are you saying that the rocker bushes can affect oil pressure? I was not able to ovhl that part of the head with the engine ovhl, as i had some money constraints.

but! i have a like new flowed head and new valve train pieces wating to go on the car... it thought it wasnt worth the work, with the oil PSI drop...

bump