'95 F150 5.0 oil issue

Figure someone might have some suggestions as I’m not getting a ton of response on FB groups.

Bought a '95 F150 right before Covid to use for hauling projects and home stuff. Odometer says 247k but prev owners says only has about 4k on after the motor was rebuilt. Seemed to run fine, starts up with no excessive noise. Haven’t put a ton of miles on it since we’ve been in lockdown/working from home but been to Pick-n-Pull in S. Dallas and back from Plano and several trips to HD/Lowes.

Decided to change the oil yesterday for the first time and now it appears as though I’m not getting any oil pressure. I find it hard to believe that the oil pump would go out exactly at the moment I change the oil. Hooked up a mechanical oil pressure gauge that I just bought at Autozone and nothing. I can’t recall how much oil was drained but could it be the previous owners put excessive amounts in to create enough pressure? Not sure what weight they used but I’m assuming stock as there was a quart of 5w30 in the floorboard.

1 Like

As long as the oil pick-up is in oil, if pump is working you’ll get pressure. If really really low on oil, if pick-up it is just barely in oil, pressure may fluctuate wildly as it sucks up some oil and the level drops and it is now sucking air and drops till oil filters back down into pan.

I assumed you put 5+ qts back in (or whatever it takes), if an external gage shows zero psi and crankcase has oil, it should show pressure.

Not sure why you aren’t getting pressure - but I’d guess pump or pump shaft is not working.

Is it possible that the pump got clogged by draining the oil? It’s just super odd as I ran the truck a few min to heat up before draining. Emptied it, changed filter, put in 5qts and started it back up and it sounded like loud lifter noise. Initially I put 10w40 in as many others recommended for the summer months but after the noise I drained it again and put back in 5w30. Not even seeing oil in the external gauge line.

Just trying to think of things I can do/check because I’m order to even check out the oil pump I have to either pull the engine completely or at best unmount and jack up to make room. Thanks Ford!

@TLAR It could be a clogged oil pump, IMO not real likely unless the oil you took out was sludge - but I can’t say for sure.

Curious: when you changed the oil and filter,has the filter refilled with oil? If zero oil pressure due to totally trashed oil pump it wouldn’t refill. But if working at very low pressure it still could fill slowly.

Tom: is there some other test he can do to check? What is likely cause of problem - your expertise is much greater than mine. Running slightly heavier oil I would think would have a tendency to increase oil line pressure. But the manufacturers weight is designed for overall system performance including film flow and thickness around bearings. The range of 5-30 vs 10-40 they have a wide overlap and at current temps I would think is a problem. I know that flippin’ Rabbit i have calls for straight 40W unless you live in Greenland or Iceland.

Not getting any oil pressure reading is a good reason to exercise causation before running.

1 Like

No, I’ve changed the filter with each time I changed it (once to begin with, again when I went to 5w30) and each time its sucked out the initial oil I prime it with but not getting any in return. I’ve not really run the vehicle long…maybe max 10 min total (over the course of many starts and stops while troubleshooting) from the time I dumped the initial oil.

Once upon a time I drained the oil on a new car and mistakenly drained the transmission instead. Stupid mistake on my part. Just make sure you are putting the new oil in the engine and not the automatic transmission. In some cars the filler cap is next to each other.

1 Like

Oh its definitely possible for me to screw up simple things but oil changes and shade tree mechanical work isn’t new to me. My first job was at a tire shop where I worked for 4 years doing oil changes on pretty much every type of vehicle. Most of my work now is on motorcycles.

On this truck I’ve already replaced all the shocks and front coils and rebuilt the entire steering column. Was getting ready to replace the axle pivot arm and radius arm bushings until this bullshit happened.

& David
Is your 95 F150 the 6cylinder(4.9) or 8cyl?(5.0 & 5.8)?

Folks buy “motor honey” the super thick additive (found in many parts stores) to try to “band aid” aging engines to “mask” noises, smoke, low oil pressure & before selling.
Did you get any documentation showing the engine was “rebuilt”?

My suggestion would be to try a heavier oil like a 15w40 - Rotella is great and inexpensive. No need for synthetic for this troubleshooting test.
The straight 6 cyl engines at 250k or so tend to shred the teeth off the timing sprockets (similar to old GM engines from long ago that used incredibly piss poor engineering with plastic teeth) the debris blocks the oil pickup and the rest is catastrophic…
Typically oil pumps don’t fail - something else causes the problem first.
Clogged oil pickup screen = drop oil pan (not a fun task)

1 Like

Its the 302, 5.0 8cyl engine.

No documentation other than the listing and what was discussed during the sale so I’m not sure how much or what of it was ‘rebuilt’. My daily drivers are motorcycles so I didn’t plan on this truck being a hard daily driver or anything other than a hauler so the rebuilt didn’t bother me. Just as an example of how little miles I put on my cars, I’ve had an 02 Mustang for 12 years and only put 70k on it.

The oil didn’t appear to be any thicker or more viscous than normal nor did I see any metal/chucks/debris in the catch pan. I can try a thicker oil. Does Rotella make a gas oil in 15w40? All I see online is diesel oil?

1 Like

just use the “diesel” rated one - most 15w40 oil will have the word “diesel” in the description - or “heavy duty”

1 Like

Are you sure the new filter isn’t defective? Get a new one and swap it out. Easy $4 debugging tool.

Swapped the filter each time I drained the oil (once with the initial change, another with the 10w40 to 5w30). Both Motorcraft FL-1A filters.

Or put the old one back on, if you still have it…

If you want to be certain the oil pump is turning but not pumping for some reason without dropping the pan, there is always the ol’ “pull the dizzy and run it with a drill” trick - the same as used for priming after a new oil pump is put in for some reason…of course, is it easier to pull the diz and put it back without fubaring the timing or some other menial little thing than to drop the pan? Opinions differ…


Just got done throwing some 15w40 in. Also swapped to an STP S8A filter as that’s what I took off during the first change. Still no f’ing pressure! Confirmed the mechanical gauge works by using my air compressor on it.

I’m out of ideas. Apparently I’m going to have to pull the engine

Did you drop the oil pan and see that nothing is blocking the intake?

[Edit: you said “catch pan” above… I assume that’s what I call an oil drain pan/bucket.]

In Ford’s infinite wisdom, in order to pull the oil pan you have to either completely pull the engine or at the minimum jack it up enough to clear the cross member. I’ve read of ppl replacing the oil pan gasket without moving the motor but I’m not sure you can see the oil pump/pick up that way

1 Like

So, here is a thought. What if you drained the oil real good, then stick a bore scope through the drain plug to inspect it.


That’s an idea, although I don’t have a bore scope. Does DMS have one that they would be willing to loan? I know tools generally aren’t allowed off site

1 Like

Check with Auto Zone or O’Reilly Auto for a tool loan.


I have one I bought on amazon, its kinda finicky, but I’ll get you borrow it if youd like. they are not too terribly expensive, like 50$ if that.