Something wrong with???

[It's a 5_0 HO]

when i start my car my oil pressure is a little high but when i rev it up to like 1500 rpms my oil pressure falls to zero and the shoots up to where it was before and when im driving it, the oil pressure sits at zero with my foot on the gas till i let off. and i can hear some tapping in the motor

 

[It's a 5_0 HO]

bump

 

[GearHd6]

Did this just start? Did you just rebuild the engine? Did you just buy the car? Give us a little more information.

 

[wicked84gt350]

Well I would check a few things First I would get a mechnical oil pressure gauge and hook it to the front oil pressure port and then drive it down the road and see if you still have the problem. If so either the oil pump is going or its cavatiting which means time to pull the motor. And it possible the pick up is causing the problem either its clogged sucking to the pan if thats possible.

 

[It's a 5_0 HO]

Did this just start? Did you just rebuild the engine? Did you just buy the car? Give us a little more information.

Sorry bout that, I just bought it bout a week ago. Its a 1990 5.0ho, T-5. I just noticed it the other day right before i changed the oil pan gasket. I figured that might have cause it. Not to good at some of this stuff.

 

[GearHd6]

Did you mess with anything on the pump itself, like pull off the pick up tube thats attached to the pump to get the pan out?

 

[It's a 5_0 HO]

Did you mess with anything on the pump itself, like pull off the pick up tube thats attached to the pump to get the pan out?

yeah i cleaned it out and then before i put it back in i primed the oil pump.

 

[GearHd6]

yeah i cleaned it out and then before i put it back in i primed the oil pump.

Hmmm.... Are you sure everything got put back correctly there? All the bolts got tightened that hold the pickup tube to the pump? If that pickup tube loosened up or fell off that could be the problem. Then the pump is trying to just suck oil from the top of the pan rather than the bottom. So when you rev the engine its dropping the oil in the pan and then starving the pump.

 

[It's a 5_0 HO]

Hmmm.... Are you sure everything got put back correctly there? All the bolts got tightened that hold the pickup tube to the pump? If that pickup tube loosened up or fell off that could be the problem. Then the pump is trying to just suck oil from the top of the pan rather than the bottom. So when you rev the engine its dropping the oil in the pan and then starving the pump.

i double checked that before i put the pan on. that is what my dad thought. are oil pumps suppose to be easy to turn cause mine was kinda hard. it might be going out. but i posted a thread bout a cylinder being out so i dont know if this is the cause of that or not. i pulled codes on the cylinder test.

 

[GearHd6]

Well if you're sure that the pickup tube is attached well then i'd move on to something easy like the oil pressure sending unit or put on a mechanical gauge like was mentioned above.

The oil pump will get real hard to turn once its pumping oil while you're manually priming it, thats normal. It'll start off easy to turn until its primed and actually moving oil through the engine, then it turns into a work out real fast.