hi all.

i posted this question in the wrong area i think so i will repost here and see what you all say about my problem

my buddy has a f150 with a 5 ltr in it.
we were getting wood in the truck when it all of a sudden lost oil pressure and sounded like a diesel the way the lifters were knocking.
we shut it down and checked to make sure there was still oil in the engine. there was but it was over full and smelled like fuel.
when we started it back up there was no noise and oil pressure seemed fine, for about 5 min that is.all of a sudden we lost oil pressure on the guage and a few seconds after that the lifters started ticking again.
we shut it down and re started it and the oil pressure went back to normal, for about 5 min again.

then , bam , oil presure was gone and lifters were knocking.

every time we shut it off the oil pressure would return to normal for a while then suddenly drop to zero.

we got it home and he told me that the oil was changed but he forgot to buy a filter and that was quite a bit ago.
we put a new filter in it. the old one was really dirty,

no change except the guage read a little higher then usual and it took longer to loose pressure but it eventually did and started rattling.

now there was a lot of crap in the old filter and i was wondering if the fuel in the oil (still dont know were it came from, leaky injector?) acted as a solvent and loosend all the sludge and crap up and then plugged up the filter and oil pick up.
anyways any input is awesome. thanks guys.

 

Yup, the oil pump pick up screen is clogged with sludge.
If he really likes the truck, it's time to open up the motor and start finding out what else is going on in there.

 

Completely agree with old93junk. There's something going on, and opening it up is the best diagnosis at this point.

 

Taking a close look at the bottom end is a good idea, but I wouldn't forget about the fuel in the oil problem also. I'm betting there are a couple of injectors that are atleast partially stuck open. I'd do a dry and then a wet compression test to see if the rings may have been wiped out in any of the cylinders. Good luck

 

In my experience, SBF's seem to be more susceptible to oil pump pick-up restrictions, than some motors, but I have also never seen one that did not recover after having the restriction problem fixed. (unless they were badly abused during the restriction)

And, as stated above there is most likely a EFI problem introducing fuel into the crankcase.

 

ok thanks guys,
the truck is a mid 90s f150 4x4.
any tips on dropping the oil pan?

also how would i go about checking for leaky injectors?
if i run then shut off engine for how long should i have pressure at the schrader valve if there is no leaks?
i do not have access to a fuel guage.

 

If the Fuel has loosen sludge and clogged the oil filter i suggest another oil change.

But to me it sounds like the oil pump is worn out.
Probably it pumps the oil as long as it is cold and thick, but loosens pressure when the oil heats up and gets thinner.

I don't know about the F150, but on the E150 you have to lift the engine to remove the oil pan.

 

its not that i dont think. as i said as soon as we shut it off and wait for the count of say ten and refire it the truck has pressure again. when it looses it all we have to do is shut it off, count to ten, refire and we have pressure again. no letting it cool

 

what is the reading with a mechanical gauge? If debris were floating around, flying around then they could have scored the gear in the oil pump. I'm with others as to dropping the oil pan or pulling the engine. Either way, you will have some sense of what has and is happening.

 

Heres my 2¢... The cheapest way to go about this is drop the pan as others have advised. When this is off, replace the oil pump and clean up your pickup tube. Could be a combo of dirt and/or a failing oil pump.

I just found a brand new Ford racing oil pump on amazon for $17 w/ shipping. They are cheap.

Put her all back together and see what happens. Unless you see a bunch of shít torn to hell when you drop the pan, you've got a good chance that there was no damage. Spending the hour or two to do this fix is way better than pulling the motor out looking for issues that dont exist. If the issue still persists after this then its only an hour or two down the drain.

 

I agree with crazy.

 

well my buddie got another truck and just gave me this one. i will be pulling the pan but not so urgent now.
hopefully get it done next weekend.
i hope the motor will be ok because the drive train of this truck is going in my hunting truck. a 1994 explorer
should be fun.
thanks for all of your advice guys. i will post what i find when i pull the pan

 

If there's that kind of crap in the oilpump, and it's making that kind of racket, then the bearings and crank are going to be toast. Time to pull the engine and either rebuild it or replace the shortblock with a new (rebuilt)one. Pulling the pan and replacing the oilpump is going to be a complete waste of time and money.