ford3251

So I've got yet another problem with this truck. I was driving home from work yesterday, got off of the interstate and oil pressure dropped from the o or normal to completely zero. I pulled over immediately and checked the dipstick ance smoke came out of the tube and was barely showing anything. Fired it back up and pressure went to just below the n and drove it home another mile. Checked oil again and it was full. Motor runs fine with no noise, drove it around another 40 miles last night and it was fine. Just pressure never goes above the n. So I'm wondering if anyone may have any ideas to what the problem could be? Clogged pump maybe? Also I want to put an aftermarket pressure gauge on it, where do I tap it on this block. It's an 86 5.0 efi. Thanks guys

GhostriderI

You can use the current oil pressure sensor port to install the aftermarket gauge. You may want to check the PCV valve for freedom of movement anf the hose/tube to ensure it is not pluged. But remember after driving at highway speed to give the oil time to drain back to the oilpan. Sometimes my oil pressure will drop to 0 comming off the interstate on exit ramp (oil moves away from the pickup tube) a few seconds later it return. You could have a pressure sensor going out (need to replace mine reads low then high on next drive). Hope this helps

ford3251

Well I just replaced the pcv, the hose should be good but ill check it. I'm gonna get a gauge tomorrow and put 10-w40 in it and see if it'll get any better

cfarmer

Have you replaced the sending unit? mine was doing the same thing until I replaced it. $10 bucks and ten minutes might fix the problem...

ford3251

Well I work at advance and I can get a gauge for 12 bucks and I can tell exactly where its at so I think I'm just gonna go that route

ford3251

Ok so I changed the oil. Put it 20w50 with Lucas stabalizer. Put in the gauge and it has 40psi on cold startup. 20 warm idleing and around 25 cruising which I thought was decent and I could live with..until it started knocking..its kind of a dull knock. A guy at work said it sounded like a piston skirt hitting a rod. We took the belts off to rule out the water pump and it actually got louder. The weird part about it is when you Rev it up to anything over a 1000 rpm you cant hear it anymore and when you put it in gear it goes away??? Pressure is still good and it runs fine otherwise. Drove it 40 miles on the interstate and it was fine. Does anyone know what it could be? Dad was thinking a bent pushrod but wouldn't that get worse with rpm? I really don't wanna tear into it without at least an idea of where to start.

Good old Bill

Have never been a big fan of heavy oils and additives. Thank you Gods for the 5W20. Contrary to the usual opinion, I like to see oil pumps do their thing and bearing clearances maintain pressure. I have pulled to many oil pans only to find the pick up screen restricted with stuff.

Engine noises are very difficult to describe and the interpretation varies. First off make sure the torque converter is tight to the flywheel, it wouldn't the first time an engine knock was misdiagnosed. Tell us again what you are doing to the engine to make it knock, eg fluctuation RPM, under load, what ever.

ford3251

The knock mainly happens on cold startup at idle. It's a dull knock, not like a valve noise. It goes away above a 1000 rpm and at idle when put in gear it goes away. Once the motor warms up it gets quieter but is still there at idle and again goes away when above 1000 rpm and in gear.

ford3251

Also since it started doing this Friday the engine at times turns over very slow and the starter clicks at times and then she will.crank up and run. The battery and starter are both good

ford3251

so after getting a scope and listening to the motor its definately in the bottom end and since i dont think it is the oil pump im guessing its probably a crank bearing, i am gonna pull the pan off tomorrow to get a better look at it but i was wondering if there was a way to replace crank and rod bearings without pulling the engine?