Valve Cover Leak - Zero Oil Pressure

Treachery · Dec 25, 2014

Will a valve cover leak cause almost oil pressure?

I have a valve cover leak that i was going to take care of in the coming weeks. But, I notice that my stock oil guage is at zero. I then hookup an oil pressure gauge to the engine and the pressire barely read above the first hash mark.

Thanks

A5literMan · Dec 25, 2014

I'm going to ask an obvious? Do you have oil in the pan? Your leak didn't run the engine low did it? Engine making any noise? Leaking oil anywhere else? Could have cracked the block? Just enough to be noticeable on the gauge. I know someone who didn't have any "noises" but was loosing pressure. Drove it for a few times and gave it a "spirited" trip and it blew. Pulled it to find the crack from the mains up to the cam bore. At least do a leak down and pull the pan to check the bearings if it has the proper amount of oil in it. Did you just loose pressure all of a sudden?

mikestang63 · Dec 27, 2014

Unless you leaked all of the oil out of the engine, then no- a leak will not cause zero oil pressure. . Did you hook up a mechanical guage or another electrical gauge to the stock sending unit?

Start with the basics

check the oil level
hook up a mechanical oil pressure gauge to the port where the sending unit is- disconnect the coil and crank the engine over or removce the distributor, take a 1/4" socket taped to a long extension and attach to a drill. Run it in reverse. With the valve cover removed, see if any oil comes to the top end and what the oil pressure reading is. You should have a minumum of 15 and 50-60 when running

Chances are the sending unit is bad. If not, it could be the following-

Collapsed oil filter
Sludged up motor
broken oil pump shaft
bad oil pump
Bad relief pressure spring in oil pump
cracked block

7991LXnSHO · Dec 29, 2014

Add to that list
Disconnected oil pump pick up
"Spun" bearing

Gearbanger 101 · Dec 29, 2014

Step 1 Check oil levels
Step 2 Check oil pump sending unit
Step 3 Check gauge cluster
Step 4 Check oil pump shaft

I had number 3 on the list this summer. Freaked me out, till I changed it.

7991LXnSHO · Dec 29, 2014

It is more common for Fox body car gauges to peg up, as in it looks like you have an Over full tank, gushing oil pressure and are over heating. That will get your attention! But #3 is an option.

SMOKUN · Dec 31, 2014

If u had zero oil pressure it would be knocking and making noise within minutes. Sending unit is cheap but if u r worried about accuracy 'as I would' put a mechanical el cheap guage in and check it out. Oil leaks will never cause no oil pressure. Only time is when u don't get the pickup tube and pump sealed as that would suck air

7991LXnSHO · Dec 31, 2014

I agree with what I think he said. Except if you let it run dry from the leak, then there is no pressure. But that is a lot of oil running down onto your exhaust and parking spot.

Treachery · Feb 1, 2015

Update: It turns out that the bearings are gone. This surprises me because the engine was rebuilt only 2 years ago and has no more than 5,000 on it which leads me to believe that the bearing problem soon started after the rebuild.

I think i made the mistake of changing the oil weight. I was running Redline 20-50 for my Mustang's entire life. I switched to 5-30 Mobile Synthetic after the rebuild thinking 20-50 is too thick.

Either way- live and learn.

mikestang63 · Feb 1, 2015

oil viscosity will not have anything to due with premature bearing life, unless the tolerances were initially wrong. Sounds to me like either the wrong/cheap bearings were used and/or improper tolerances/installation. Bearings don't wipe out in 5k miles. I would mic the crank, main and rod caps. Looks like you have a complete teardown and rebuild ahead of you.

2000xp8 · Feb 1, 2015

This is exactly why I don't like basic rebuilds and prefer junkyard factory engines when sticking with a 302.

mikestang63 · Feb 1, 2015

2000xp8 said:
This is exactly why I don't like basic rebuilds and prefer junkyard factory engines when sticking with a 302.

Yep- people poo poo me when I tell them to get a JY exlporer motor for a few hundred bucks unless you plan on building a stroker or high buck rebuild.

madspeed · Feb 1, 2015

people poo poo you? do explain

mikestang63 · Feb 1, 2015

madspeed said:
people poo poo you? do explain

Man, talk about walking into that one face first. lol No grown man should say poo poo and I did. Must be the jack n cokes.

madspeed · Feb 1, 2015

mikestang63 said:
Man, talk about walking into that one face first. lol No grown man should say poo poo and I did. Must be the jack n cokes.

I concur... to the Jack n Cokes !

Valve Cover Leak - Zero Oil Pressure

Treachery

A5literMan

At least it is lumpy...

mikestang63

7991LXnSHO

wanna catch the space herp

Gearbanger 101

Straight Outta Locash

7991LXnSHO

wanna catch the space herp

SMOKUN

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7991LXnSHO

wanna catch the space herp

Treachery

mikestang63

2000xp8

mikestang63

madspeed

Colonel Mustard

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