My friend has an F-250 with a 5.0. with 250,000 miles. He looses oil pressure after the motor warms up at high rpms.( like when he passes someone on the highway). He had the pump, pick up tube and pan replaced new a year and a half ago. It did it back then before the replacement parts also. any ideas? bad pump? sludge? something else?
Jerry
sounds like somethings blocking the sending unit. that motor wouldn't last long with no oil pressure at 3500 rpms.
Time to hook up a true mechanical gauge and go for a drive......
The gauge is working properly. He has to shut it down because the engine isn't circulating oil and starts to tic.
The last of the 318's they put in Dodge trucks would do something similar. The lifters were usually the culprit. Those held good pressure though when warm though......
If the cold pressure is within specs, this is sign of worn bearings......what weight oil is on it now?
pull the sending unit off. then pull the distibutor and re-prime the pump. if you don't see any oil coming out where the sending unit was then you have a bad pump. if it does come out you have a bad sender.
BTW, my old dodge had an oil pressure issue, but was the reverse of your friends. I woul lose oil pressure at a warm idle. that was due to sludge. I did everything I could do to remove it, but the only remedy would be to have the block vatted.
He's probably running 10w-30
he may be pumping all the oil up on the heads, and the oil return holes are clogged with sludge and letting the oil pan run dry.... pop the VC off and se the oil returns clear ...
He's going to check that first.
Can the oil pick-up move in a 5.0? I had a small block chevy doing this once and the oil pick-up was pressed in and moved up highter (I think this happened when the pan was put on). So it was not down as low it it should have been and staving for oil when the oil moved back under higher RPM.
I can of feel bad not knowing about 5.0 engines and being on this forum.
TED
5.0/302 has a bolt on pick up, yes the bolts could shake loose, also there are gaskets between the the pick up and pump, and the pump and the block.
if the pick up was loose, or the gaskets failing, he would not have oil pressure at any time, for it is easier for it to pump air than oil.
High volume pump + stock size oil pan = potential for oil starvation. Make sure it's FULL.
I have an 8 quart pan & pickup awaiting install with Chucks mounts and some other goodies......
He does have a high volume pump that was put in last year.
then that's why he's losing pressure.
Might be a combination of both of these 2 things together with the mileage that truck has. Just my .02
:burnout:
I went back and re-read the original post. I'd pull the intake off as well and clean the oil drain back holes there also.
On Ford Modular motors, specs call for 6 quarts. You can run more than this without issue.......Guys run 6 1/2 even 7 in some cases for the very reasons cited, especially the 4v guys. Those motors like keeping oil up top and they have excellent flowback characteristics.....
Make sure it's at the absolute full mark on the dipstick and buy a GOOD oil filter for it. I've tested some different ones personally. A certain brand makes the warm idle pressure 4 PSI lower on my Cougar....It's a brand we all dislike here anyway....
It's not a mod motor. It's just a run-of-the-mill 302
I was citing the mod motors as an example.
May I ask which brand you're talking about?
FRAM huh???!!!
Wouldn't put one on a mower.
Correct answer stated above ;)
the only good thing about a fram filter is th "quick grip" so you can get it off your engine faster....
I personally think Wix or NAPA Gold are the best common filter out on the market.
Motorcraft FTW:D
better yet,,, dont risk sludge falling in places you dont want it....
transition a shop vac to a piece of 1/4'' copper tubing.
vac the oil return holes out.
the 1/4'' tubing will go all the way to the crank or pan.
250,000 miles, I would think it may have issues. I'm sure at idle the pressure is not so good either. It's tired!!
It may be just that... I think we'll have some sort of clue or direction this weekend.
Motorcraft filters are made by Purolater, aren't they?
My dad has an '89 F-150 with the exact same problem. It's been parked for 4 years now, so I don't know the cause, but I'd suspect high miles have a lot to do with it. 5.0's ARE notorious for this, especially those particular years. And, there's a reason they say not to use a high-volume pump on a stock engine ;)
Hope ya get it nailed down painlessly :D
Stock replacement pumps are more than sufficient for most street engines (do some research on Dick Landy's engines).
Fram = FAIL
Motorcraft FTW
However my old 5 Star International sales rep saved us a ton of $$$ on a Cat 930 that smoked an engine. The International Filters, FleetGuard offer a engine replacement guarantee if a engine goes tits due to an oil filter failure. I run a Fleetguard on my 03 F-250
5.4L and have noticed no difference in oil pressure.
HMMM now that i think about it, the Motorcraft/Wix/Fleetguard filters all look the same....wonder who really makes em....
Fleetguard makes good filters. My buddy uses them on his diesel F-series.
Fleetgaurd or Donaldson. Are high quality filters, Recommended by most oe manufacturing. But for cars it's tough to find normal part stores to stock them. Personally I use wix.
True, but you can always goto your local 5 Star International dealer and buy a couple of the filters.