Low oil pressure at high rpm

[Xentro]

I was wondering if anyone can tell tell me if this is normal

I notice my oil pressure actually goes down as the rpms go up.

When it idles it's just above the red marker
when cruisin is almost at the middle marker but when i get above 3500 rpm it gradually drops to about 1/4th or less

By the way this is all with a warmed up engine
when it's cold the pressure is about 3/4 on the guage

I must add that a couple months ago the lower balance shaft had spun a bearing so I cut it off and blocked the hole with a long m6 bolt & locktite
I just left the other one in the block but removed the small belt

Apart from the low oil pressure the engine runs great.

[Cookiemonster]

My car did the exact same thing... until I fitted an aftermarket sender and oil pressure gauge.

[David]

Sounds like an aftermarket sender... Also, other Mitsubishi replacement senders also work the other way around.

David

[Xentro]

I think it's the orginal sender but you can never be sure with a car this age.

But the funny thing is.. when i start it in the morning the oil pressure is in between te normal levels

the pressure goes up as you rev it to about 3000-3500 and then it starts to drop off again..
But it only happens After the engine is warmed up.
I must add that a oil change is due and it might be because it was topped off a couple times with different oil then was in the engine..

[SpidersWeb]

My car used to run out of gas when the fuel guage read 1/4 of a tank. The fuel light came on at about 1/2 a tank. Oil guage wasn't very reliable either. I wouldn't have too much faith in the old guages.

Cookie's idea of an aftermarket setup is probably best, and not terribly expensive.

Using different oil combos wont make the guage read funny results, results may change, but they wont be perculiar like these.

[Xentro]

Hmm guess i'll swap the sender with the one from the spare engine i have next time i change the oil and see what happens

[Cookiemonster]

I think it's the orginal sender but you can never be sure with a car this age.

But the funny thing is.. when i start it in the morning the oil pressure is in between te normal levels

the pressure goes up as you rev it to about 3000-3500 and then it starts to drop off again..
But it only happens After the engine is warmed up.
I must add that a oil change is due and it might be because it was topped off a couple times with different oil then was in the engine..

Thats exactly what was happening with my factory sender and factory gauge. I think David misunderstood what I was saying.

After I replaced the factory sender and gauge with aftermarket types that sympton completely dissappeared. So I can only atttribute the fault to a bad factory sender or a bad factory gauge.

[TD05]

I had a similar problem, I took the sender apart and cleaned it, put it back together and it worked like a dream.. 1 hour tops.....

http://austarion.com/forums/view ... oil+sender

btw, these senders aren't fluid proof, so driving over a puddle or degreasing the engine with a high pressure hose might do it..... when fluid gets inside they stuff up

[Barney]

Check your oil pickup in the sump. Thats the same symptom my misses Honda had, I thought it was the sender, next thing you know i was rebuilding the engine. :(

ASHLY