Sudden loss of oil pressure.

Topic: Sudden loss of oil pressure. (Read 9129 times) previous topic - next topic

Sudden loss of oil pressure.

October 10, 2013, 07:23:09 AM

This year I've put 2 oil pressure senders on already, and I had my indicated oil pressure drop to nothing last light after a 3 to 4 second WOT sprint. I don't have any lifter noise, but I do have a faint hint of the rattle noise you'd expect from loose rods. I'm going to bring a sending unit home from work today and maybe a manual oil pressure gauge to test with. Anybody think it's something else? I had a friend with a 333 blow his lifter/cam oiling plug out (back of the valley near the rear sealing rail) but he immediately had lifter noise. I just don't want to have to tear down. My engine had 120k last year before I put it in, but I can't think of anything that would cause a sudden pressure loss without being accompanied by audible evidence of catastrophe. Thoughts?

Sudden loss of oil pressure.

Reply #1 – October 10, 2013, 09:59:05 AM

your doing what i would,, and i agree with what you said...
but you may want to install a fitting that keeps the sender that reports to the dash, and..... install the manual gauge.

this way when your dash says one thing, you have the manual gauge to compare to.

almost restorted to this but found my issue.

the long tube oil sender adaptor could be drilled / tapped i suppose so its provisioned for both items.. its an easy work around to monitor things for a while.

if you see the dash say low but your manual gauge says good, then you know right off the bat its cluster / wiring related.

btw, you should do that high wattage resistor mod to your cluster anyway,,, that resistor gets very hot. .. place a piece of soap stone underneath it.... i have a link to the thread in my diy section. if you end up with the cluster as the issue then you might as well do this mod to.

Sudden loss of oil pressure.

Reply #2 – October 10, 2013, 10:14:32 AM

i have no idea if you took the time to take the oil pan off and "bend up" slightly the oil sump. I was warned about the clearnace of the sump to the bottom of the pan and the fact the oil pump could scavage or empty itself out because the sump is clearing the bottom of the pan with very little clearance. this really makes no sense to me but my boy and I just ever so slightly bend the tube so the profile of the screen is up abot another 1/8'' or so.

anther thing, if you didnt take the pan of that explorer motor, you may not know for sure if the screen as enough clogging to introduce scavaging.

I think once upon a time i tried to fish in a spray tube like the little red ones that come on carb cleaner and attemped to guesstimate and spray off the sump screen using the oil fill plug hole as my entry point.

if it is the screen partially clogged,,,
you may want to risk taking out the dizzy,, drain half your oil, put in a could qts of paint thinner or MEK, run your oil pump shaft with a drill to prime / wash stuff, perhaps even do this with the oil sender out so the galleys get cleaned, then run your drill in reverse to to push thing back out into the pan,,,,

then,,
fill drain all the old stuff and add new, run your drill to reprime the motor then put the dizzy back in and monitor things for a while.

Sudden loss of oil pressure.

Reply #3 – October 10, 2013, 10:18:49 AM

siri does me no justice when im speaking my messages... some of my posts lately look retarded! lol

Sudden loss of oil pressure.

Reply #4 – October 10, 2013, 10:58:15 AM

I had the Explorer motor open last when I installed a Ford Racing standard oil pump, non-hardened shaft and Fox pickup and new Fox oil pan (during the Fox chassis conversion). That was more than a year ago. I've got 3/8" clearance to the pan bottom, I think that should be enough.
I would suspect the cluster resistor if the problem went away after sitting over night, but this unhappiness was still there this morning. I think I may get an electronic oil pressure gauge for my clock mount and swap the stock sender for the autometer one, then leave the wire for the cluster oil press gauge grounded somewhere. I don't want to listen to that ed chime.

Sudden loss of oil pressure.

Reply #5 – October 10, 2013, 01:06:24 PM

When I had my 87 with it's original 5.0, the oil pressure did drop enough to beep all the time with no engine noise. I installed a manual gage in the little panel to the lower-right of the steering wheel (where the turbocoupes have the premium/ride switches). The manual gage showed like 12psi when cold, and about 4psi when warm. It ran fine though. I eventually replaced the motor with a fresh HO, then it read 50-70psi. Low oil pressure is common on windsor blocks, especially high-mileage ones (I don't know how old yours is).

Sudden loss of oil pressure.

Reply #6 – October 10, 2013, 01:53:59 PM

Confirmed. No oil pressure.

Will proceed with standard base engine diagnostics. Currently I am planning to reinstall the manual gauge, pull the distributor and visually verify pump shaft. If it's still there and intact, I'll spin the pump and observe pressure. Depending how the gauge reads, I'll pull the intake next and verify the cam and lifter oil feed channel plug. If I'm still good at that point, I'll have to drag it to the shop and pull the engine.

There are no external leaks, BTW.

Sudden loss of oil pressure.

Reply #7 – October 10, 2013, 05:30:54 PM

Ok, primary diagnostic is complete. This pic isn't of MY pump shaft because I couldn't get mine out through the dist hole, but here's what's up.

So, we pull the engine, flip it over and go after the oil pump which will no doubt be jammed/siezed or otherwise FUBAR'd. I'll have to get the pump apart to find out why this happened. As far as I know, the Ford Racing standard oil pump is a high quality unit, but whatever. I'll be switching to a hardened drive, recommendations for a standard pressure/volume pump?

Sudden loss of oil pressure.

Reply #8 – October 10, 2013, 07:37:38 PM

Melling 68

Sudden loss of oil pressure.

Reply #9 – October 12, 2013, 10:36:35 AM

i have a recommendation,,
home make a gasket that matches the exterior profile of the housing that holds the gears on the oil pump.

i have no clue why it bugs me but evey time (and this isnt very often but...) every time i take a cover off an oil pump, there are signs of the gears rubbing the cover and you have to wonder if its not because of the clearances being too tight.
i make a simple gasket around the exterior profile of the pump then assemble to add about .020 more gear to cover clearance.

your not actually saying your pump shaft is broken,, your saying the pump is jammed but the pic shows a broke shaft.

"if the clip were slipped up too high" on the pump shaft, that would certanly put downward force on the drive gear and cause it to be under constant friction.
can you remember if you were just piddling around moved it a little?

what you want is to have the clip positioned in such a manner that when installed, it does not rub the block,, its just a part that says put, it should have at least enough gap betweent he clip and the block such that when the distributor is extracted, the shaft iteself is still seated in the hexagon shape of the oil pump.

with no dissy installed, the shaft can have at least 1/4 inch or less up and down motion.

when i put my sons oil pump in,, i used the shaft from teh explorer motor and i noticed that when i snuged down the pump mounting bolts, the pump drive shaft clip was all the way up againt the block. i took stuff out again and lowered the clip a little bit and that solve the bind.

im pretty sure it would have eventually loosened up ,, Maybe? but doing what i did made darn sure it wastn an issue.

Sudden loss of oil pressure.

Reply #10 – October 12, 2013, 10:37:05 AM

Sudden loss of oil pressure.

Reply #11 – October 12, 2013, 11:15:35 AM

The pic isn't mine. Mine is still in the engine, broke off right above the pump. I didn't have a clip on mine, when I pulled the distributor the long Parr of the broken shaft fell. Next week when I pull it I'll put up pics.

Sudden loss of oil pressure.

Reply #12 – October 12, 2013, 03:47:10 PM

Jay the gear to cover clearance is .005-.008 If you install a gasket under the cover you are making a very bad mistake. The reason there is no gasket is because it can blow out. To my knowledge i do not know any oil pump that i can say has a gasket. Adding .020 is extremely Dangerous and gasket blow out is going to happen if you do this. Those gears are designed to rub on the cover that is how it works. Normally i set the cover clearance to .003 - .005 . Anything more can cause the pump to loose PRIME. DO NOT DO THAT JAY. Trust me on this!!

Sudden loss of oil pressure.

Reply #13 – October 12, 2013, 05:42:37 PM

Melling 10687 and ARP 154-7904. That's what I've settled on. The 10687 has adjustable output pressure, which I plan to increase to somewhere between the pressure of the M68 pump and that of the M68hv. It also has gear shafts that are supported into the cover (which itself is thicker to reduce deflection).

Sudden loss of oil pressure.

Reply #14 – October 12, 2013, 07:03:13 PM

Interesting Tom

The paper I use is called fish paper and I think it measures out at 20,000 but when you tighten down the bolts I'm sure it smashes down

You learn something new every day but lucky for us his oil pressure is just fine for now