I had a 95 F-150 5.0

I have a problem with oil pressure constantly fluctuating. There are days when the oil pressure is solid all day, and then there is days when it would be normal and then drop to nothing, shut it off for an hour turn it back on and its back up there. The only crazy thing is when the oil pressure drops it never ticked or knocked once, Untill today. I started it this morning and it had no oil pressure and it ticked like crazy.

Four hours later , I fired it up. It had 3/4 oil pressure after 5 minutes the ticking stopped.

What do you think would cause such an odd problem?


Thanks for any help.

 

Welcome to F150 Online. Be sure to check around and use the search button - there is an enormous amount of good info available here.

As far as your oil pressure problem, here are some ideas:

1. Low oil level.

2. Bad oil pump.

3. Damaged oil pan.

4. Damaged oil pump pickup (sump).

5. Sludge on oil pump sump screen.

If you have eliminated #'s 1-3 by visual inspection, I'd drop the pan and check for #'s 4 & 5.

# 5 is pretty common, especially on higher mileage engines without regular oil / filter changes.

DON'T run the engine for 5 minutes when it is "ticking" or exhibiting signs of oil starvation. Serious engine damage is almost certain to occur.

Good luck and let us know what you find...

 

Thanks , I do know that I shouldnt run the motor but I wanted to see when it would start feeding oil.

Im sorry for not really using the search. But I thought maybe this was alittle beyond a common problem.

Im sorry I did not mention that
1- oil is clean
2- oil is at correct level
3- this is a 75,000 engine

But your ideas 4-5 are ones im thinking maybe the problem.

I dont see how the oil pump would flex pressure on me just occasionaly. Ive been around 5.0s for a long time and never seem to have a problem with oil. Either the pump is broke or its not.

Im about to pop off the pan and get a look but I just wanted to see if you had any ideas on something I could be missing. But I really think the sump could be the problem.

 

Pinzonie -

Please accept my apology if I came across as harsh. I was not ridiculing you for the search button - rather just pointing out that it is there. Many new members don't notice it until after a while, so I thought I would just let you know it's there...

Anyways, I agree - oil pumps usually work or they don't. However, the day I rule it out would be the day Mr. Murphy shows up...

Anyway, I read on this board once that someone had the exact same problem you are having and it turned out to be a bunch of sludge in the oil pan getting caught in the sump screen.

Good luck and keep us posted.

 

Thanks man, Sorry if I came off as a know it all.

I wasnt trying to make a first post like that. I understand the search feature. I just noticed how many posts are on this site. I will do some digging.

Any memorys of that thread you speak of? Title? lol


I'll look.

 

With 75,000 miles and fluctuating oil levels...i would venture to guess that you rengine is just fine. Its most likely just the sending unit. Ford has a funny oil unit...pretty much anything above 7psi, and the gauge reads "OK". So for that gauge to register a fluctuation is almost impossible. If i remember correctly it is nothing more than a switch type of guage.....in that you might have 40psi, 60psi, 80psi, or 10psi.......the guage doesnt know or care......it knows that you either have pressure or you don't, yes or no, on or off. If you are not hearing any noise and you change your oil regularly, then you are most likely just fine. However, when it comes to oil, it is always best to check it out for yourself. Since this is somewhat of an intermediate problem, you may look in to putting a mechanical oil gauge in your truck, somewhere inconspicuous so that when your dash gauge goes nutty, you can peek down and see what the pressure is really doing.
The reason i say all of this is because I had an oil pressure problem too. My oil gauge in my truck does actually read pressure, but not really all that well, it says i have 40psi, as long as i am between 45-80psi.....which is fine. But my gauge started doing wierd things, and i placed a mech gauge on it, and now found out that when the dash gauge was going crazy, the mechanical gauge was rock steady at plenty of pressure.....so that answered my question. The sending unit was replaced to no avail.....so its just something with the gauge that doesnt work quite right.....but it doesnt matter cause the oil pressure is fine. More importantly, i can see EXACTLY what the pressure is at any given time.

Hope this helps!

 

I also believe I would suspect the sender. The wire is probably loose on it. On my 4x4 it is quite easy to loosen the wire when changing the oil filter.


tom