No Oil Pressure at start up 5.0L

[PAshooter]

So I have a ranger with a 99 mercury mountaineer 5.0 in it. Swap was completed a month ago but last week when I started it up the oil pressure gauge was below the L until it warmed up.

Im not sure what could cause this, Oil pump?

 

[IAmTodd]

I'd replace the pressure sender first. It went on my 2000 and did the same thing.

 

[deweyville65]

So I have a ranger with a 99 mercury mountaineer 5.0 in it. Swap was completed a month ago but last week when I started it up the oil pressure gauge was below the L until it warmed up.

Im not sure what could cause this, Oil pump?

If the engine doesn't make any strange noises, like valvetrain clatter, then I would say it is just a sending unit problem. But, maybe you should hook up a mechanical gage, if just temporarily, just to be surd.

 

[PAshooter]

Thanks for the replies, i forgot to say, it does have rocker knock when it the gauge reads no pressure.

 

[deweyville65]

When was the last time the oil was changed? If recently, try changing the oil filter. If that doesn't help, you are going to have to pull the pan and change the oil pump at least, before you loose the bearings. This is based purely on what you have posted.

 

[windsors03cobra]

I would look at the oil pump drive, are you using a dist. or using the DIS ?
Def. need to get a mech gauge on it and see what ya got, could be trashed mains, the pumps are very reliable. Does it knock upon cold start up ? Main bearing knock specifically.

 

[tregare]

also, what oil filter are you using? Fram filters have a bad habit of allowing the oil in the filter and engine to drain back into the pan. Wix, NAPA and several other brands of filters have good anti-drainback features.

 

[PAshooter]

Fram filter...what does main bearing knock sound like?

And it is always at a specific temp, once the knob hits the C line it jumps up. Im gonna drain oil and use a new filter.

 

[tregare]

Fram filter...what does main bearing knock sound like?

And it is always at a specific temp, once the knob hits the C line it jumps up. Im gonna drain oil and use a new filter.

friends don't let friends use FRAM get wix.

 

[wood1]

Put a proper gauge on it and check the pressure.

 

[SoNic67]

Doesn't need. He has no oil pressure, because of the audible knock.
Probably will damage the engine soon driving it like that, for minutes whithout lubrication.

 

[wood1]

Rocker tap or rod knock? You can get a pressure reading in a couple seconds.

I let a dealer change an oil pan seal on my old 5.0 back in the day, lazy #######'s dropped most of the gasket into the pan which plugged the oil pump pickup some 3 years later or so. I shut it off when it started tapping and pulled the engine, it was obvious.

If you have a tap life is still good. If you have a knock, you are going to spend some money.

Good luck.

 

[PAshooter]

Rod knock would constantly be there correct?

Ive only ever heard rocker tap(ive always called it knock), but it sounds like rocker tap. It goes away once I regain oil pressure. I just changed the oil and i will see tomorrow when i fire it up if it fixed it.

If not...I guess im pulling the engine.

 

[SoNic67]

Use oil that has 5W40: 5W is good for start-ups with cold engine.
40 for low pressure at operating temperature (if needle jumps at idle rpm while engine is warm).

 

[wood1]

Rod knock would constantly be there correct?

Ive only ever heard rocker tap(ive always called it knock), but it sounds like rocker tap. It goes away once I regain oil pressure. I just changed the oil and i will see tomorrow when i fire it up if it fixed it.

If not...I guess im pulling the engine.

Sounds like a tap to me. If you had a bad road bearing that wouldn't get quieter with higher pressure.

I would still get a proper pressure gauge and check your pressure. If your engine is sludged up a bit you can try a couple different things to free things up.