Oil pressure prob ??

[jonnyd61]

Been having probs with my oil pressure droping has car warms up it starts off fine sits at 75psi then starts droping slowly to 0 ?. Was told it was pressure relise valve so i cleaned the valve half way throght warming the car up thinking the pressure would go bak to 75psi bt it didnt It carryed on droping slowly what could the prob be ???

[mowgli]

1. what engine?
2. what mileage
3. does the light go on too?

[meritlover]

Wrecked breaings
wrecked pump
wrecked head gasket
choked pickup pipe
terrible oil

[Andy]

whats to say the gauge is accurate?
Needs a proper pressure test for a start

[jonnyd61]

Its a 20xe had top end rebuild with millers 10-40..i tested the oil pressure with a with a mechanical gauge first it sat at 5 bar for a few seconds then droped to 4.5bar and stayed there. I didnt leave the car to warm up with this gauge so im not sure if it wud have droped lower than 4.5 ? It seems wen i take here for a run up and down the road wen i come to stand still (ideling) it drops faster
For example it would be at 50psi on my gauge take her up and down the road come back and it will haved droped to 35-25 psi if i do it again it drops even lower.could this be a weak oil pump ???

[jonnyd61]

i also have clean the sump and pick up pipe bt i have nt put it back together and tryd it becouse i cant see a dirty sump and pik up pipe cousing this prob plus if it is the pump im half way there to stripping it lol

[jimbob-mcgrew]

did you renew the rubber o-ring where the pickup pipe attaches ?

I hear you run into pressure problems if you don't replace it after pipe removal.

pump might be suspect otherwise. I dunno much about them, is there ways of checking / testing them to see if there shagged ?

[jonnyd61]

cheers for reply no I havnt renewed the o ring on pik up pipe. im just at wits end with it cant understand why its running proper pressure for first 10 mins then very slowly starts dropping if a rev it to 3-4000 the pressure goes up bt drops bak down to say 25-30 psi and then goes even lower after more reving ???? what the f*cks goin on

[tom reid]

It's most likely the clearances in the bearings opening up when the engine gets hot, check your bearings, especially as the sump is off.

[simonm]

Check it with a proper gauge again and run it on it. What kind of gauge and sender ate you using

[jonnyd61]

the gauge is off ebay must be working correctly cos wen it showed 0 pressure I undid the oil cap and there was no oil pissing out of it at all and the lifters got loud ?
the mechanical gauge I havnt drive with that one on cos its a short pipe plus think that's just for wen cars at a stand still idling rev ect ??