Oil Pressure Dilemma

[FLSTSS]

Here's the problem: When I start the truck cold the OP is 50psi after the warm up I drive about a mile the OP goes to 40psi and 30psi @ idle, after another mile while driving OP is 35psi and 20 @ idle. After another 10 mins of driving water temp is 195, and max OP is 30psi and 10 @ idle It was never that low. A few more mins same WT driving pressure is around 25-30psi but the idle pressure ia near 0 causing the check gage light to come on. If I let it sit in the driveway at idle it stays a 8-10 psi no lower. It just started doing this. I had a stalling- starting problem the truck stalled around 10 times before I had it towed home. I changed the batteries, OPS, oil and filter, the fuel filter (the cause of the stalling I think DUH!) cleaned connections, check voltages. It now starts right up and runs, but now the new problem. I put a tee in the turbo oil feed line with a mech OP gage and the pressure is the same as the factory gage. changed the oil and filter again, still same thing. Pulled the filter housing off, oil cooler line pressure spring moves freely as I pushed it up, a bit of oil ran out. I don't hear any odd noises I checked the engine with my stethoscope still nothing. Any thoughts?

97 1500 6.5LTD 157000mi 4WD

Thanks so much in advance!!

[Robyn]

Maybe someone else here can hit on something I have missed in our Pm's

Hope so as I am at a dead end at this point.

Good luck :)

Robyn

[FLSTSS]

Me Too! Thanks Robyn

[Slim shady]

Sounds like you lost one of the oil galley plugs in the front of the engine. These are pressed in and have been known to come lose and cause the exact problem you are describing.

The only way to tell for sure is to pull the front timing cover off and see if it is missing. Unless you have a scope and can go down the oil fill tube AND LOOK.

GOOD LUCK SOUNDS LIKE YOU COVERED EVERYTHING ELSE.

[FLSTSS]

Hey Thanks for the insite Slim, We were also toying with the idea of the oil pump pressure spring going south.

[john8662]

My idle pressure is the same as yours w/ my '97 oil spray block, but reved up I still see 50 psi (3k RPM tho).

Could be a failed or failing oil pressure regulator valve, they do stick on some pumps, causing abnormal pressure all of a sudden.

J

[rjwest]

Try a new oil filter, easy things first.....

Usually when a new problem, last thing fixed is the problem...

[Robyn]

The 97 should have threaded oil galley plugs.
I have a 506 block in the shop on a stand and it has threaded plugs on the passages.
Could still come out but not as likey as they are put in with some type of goop.

Still possible a spray nozzle could have dislodged leaving a huge hole wide open to dump large amounts of oil rather than a fine stream.
The oil pressure regulator is certainly a good shot too.

With the miles on the clock, If it were mine I would just yank the sucker out and crawl through it carefully.
Good time to replace head gaskets and have a look at the innards of the little beast.

It just may be that you might find some issues that are just ready to go away and be able to fix them before they become bigger issues that could leave you and your family stranded. :eek:

Doing and engine R&R is not that big of a deal and you can clean things up and generally police things up while your in there.

Doing an inframe on these is a PITA. its can be done BUTTTTTTTT.
With the engine out you can get intimate with everything and see things soo much better than in the rig.

I know that pulling the engine sounds like a pain but it's not that big of a job.
I did my 94 by myself in about 8 hours and I dont work fast or hard.

(Had a quicky helper to get the hood off is all)

Good luck

Robyn

[FLSTSS]

Still possible a spray nozzle could have dislodged leaving a huge hole wide open to dump large amounts of oil rather than a fine stream.
The oil pressure regulator is certainly a good shot too.


Robyn

John Thanks, I'm leaning towards the pump.

Hey RJ thanks for the info, Thats was the 1st thing I did "great minds think alike"

Robyn,

"Beyond great minds" what is the spray block or nozzle? And if it fell out can it easly be put back in and done while the pan is down? I think the first thing I'll do is drop the pan and change the pump and see what it looks like down there, if that works yea! if not then I'll yank it.

What is a good oil pump to use?

Thanks Everyone

[Robyn]

Get a factory pump, they come with the screen already on them. :)

If a nozzle fell out it could be still rattling around in the pan unless it got flushed out on the last oil change.
I dont think you could get up in there to do anything as the nozzles are on the upper side of the main webs and spray oil up into the piston as it rolls past BDC
The area in these engine is tight with the crank and rods all installed.
You may or may not be able to see the nozzles.

Good luck

let us know

Robyn