Oil Pressure Quest...replacing main bearings, rod bearings, and rebuilding pump.

[RED-85-Z51]

Well Ive got all the parts in my basket at Team Grand Wagoneer.

Complete main bearing set.
complete rod bearing set
Rod cap bolt set
Oil pump kit (2 rotors, spring, gasket, and the thing on the spring)

i think that's all I ll need, ordering the pan gasket from work.

Looks like the oil pump is a cinch, not worried about that part at all, looks like a 45 minute job at best.

But the bottom end bearings, could pose a problem.

MY issue is oil pressure, or a lack there-of. 10psi at idle, 20psi running 60. So far no engine knocks, and the lifters arent collapsing, doesnt burn any oil at all, but leaks it like mad. I know the front main is gone, and probably the oil pump housing is leaking now as well.

I trust the electric gauge, and the new sender I installed, PRessure is high cold, but after about 3-4 miles of driving it starts to slip down.

Not pulling the engine or trans...doing it all under the vehicle itself.

It's my ride to and from work, and Im only at work for 8 hours, do you think this is doable? We have a full time auto tech at work, so I can get him to help if need be, and my boss is fully ASE certified so he can help as well.

Picking up a Haynes manual next time im in town, but Im HOPING to do this job next week...Im going to drain a little oil out and put in some 15-W50 to bump the pressure for the time being so it doesnt hurt anything.

I dont feel like it is worth replacing the cam and cam bearings due to the labor involved..and the fact the cam spins half the speed of any other part.

Any suggestions are greatly appreciated, this will be the biggest mechanical undertaking ive attempted on an automobile...

[shackwrrr]

For the first thing dont get your engine parts there we have all heard horror stories of shipping and whatnot

Go to www.fastengineparts.com

call them and order your parts.

I still wouldnt really trust that guage do yourself a favor and get yourself a 6 dollar oil pressure guage and check it. you may end up only being out 6 bucks but if after that it still isnt good keep on reading

Im sorry to say but your problem may be more than a few things, The oil pump gears are hardened and they sit in an aluminum case so the gears arent usually the problem. the timing cover where they sit gets all scored and they dont seal anymore.

Next your mains may be worn but I dont think thats as much as a problem as your think. Cam bearings seem to be where usually you loose your oil pressure. Im sure if you took your pan off that you probably have some nice flakes in there from the cam bearings. once you start loosing that much oil pressure usually the engine ends up coming out. but I would try the cheapest thing first and thats the guage. Then what helped my oil pressure was that my pressure relief spring got weak I shimmed it up and now its compleatly normal.

[RED-85-Z51]

I can replace the oil filter housing as well, it's only about 35 bucks more...

[RED-85-Z51]

Also, when I changed the oil I ran it through a paint strainer and there was no metal flakes I could see, some gunk chunks, but no obvious metal, even in sunlight I couldnt pickup an abnormal glisten in the oil.

This thing has probably been running pressure this low for a while now...

[Hammer]

The END clearance is the biggest issue with low oil pressure. Trust me on that one. The grooves in the side have to be pretty bad to make a difference.
If the gears have worn a figure eight into the oil filter housing, you need a new housing, and to set the end clearance properly.
www.bulltear.com for the gaskets with different thicknesses. Makes the job very easy with those!
I would work the oil pump over before digging into the bearings.
And I also agree, a cheapo mechanical gauge is a cheap investment, and well worth it.

[hcm]

Do you have a plan for the rod bolts that doesn't involve removing the rods from the engine? Removing and replacing these bolts changes the shape of the big end bore enough to require resizing on a rod machine. I would save them for the day when the engine comes out for a complete rebuild.

[Ristow]

correct. leave the rod bolts for now. they have to be pressed in and out as well. and get AR bolts when you do.

summit will likely be cheaper and faster on getting the parts to you.

Do you have a plan for the rod bolts that doesn't involve removing the rods from the engine? Removing and replacing these bolts changes the shape of the big end bore enough to require resizing on a rod machine. I would save them for the day when the engine comes out for a complete rebuild.

[smearig]

I'm with the others on starting with the oil pump and getting a mechanical gauge. Somebody put the midplate on mine and it cranks out a ton of pressure. Even when the front cam bearing looked like this it would put out 20 psi at hot idle.

[82 Widetrac]

Hey that looks like mine!



Russ

[RED-85-Z51]

So new pump kit, and new filter housing, gotcha Ill order those first/right now. Glad I held off until hearing back from you guys.

Am I hurting the 360 by driving it with these kinds of pressures, even using good oil?

cold idle is around 40psi
Cold cruise is 55psi

Hot idle is 8-10
Hot crusie is 20-25


SO that's what a bad oil pump does?

[Hammer]

That isn't enough pressure to be driving it.
It's enough to move it around, etc. But it is NOT enough to put any kind of load on the motor.

One thing to check, look for movement of the balancer.
Can you pull it out and push it back in?
Seems like the thrust is the first crank bearing to have wear.

[RED-85-Z51]

That isn't enough pressure to be driving it.
It's enough to move it around, etc. But it is NOT enough to put any kind of load on the motor.

One thing to check, look for movement of the balancer.
Can you pull it out and push it back in?
Seems like the thrust is the first crank bearing to have wear.

Ive been putting 45 miles a day on it, 22.5 to work, and 22.5 back, with a 7 mile stint in both directions at 65mph sustained.

Now, While im crusing at 65 the pressure holds steady at 25psi, sometimes creeps up to 30psi...I dont have to stop all the way to work, once I leave the house I have one light about a halfmile down the road and then its' smooth sailing.

If I slow down to 35, the pressure drops down to the 20 range and holds there.

[RED-85-Z51]

As for crank thrust movement, Ive seen it on other vehicles, the crank wiggles in and out when you crack the throttle, mine isnt doing that at all, but I havent tried to force it myself either.

Think some Lucas oil Stabilizer would help?

[duncanstives]

I am no expert but heres my thinking: Low pressure is caused by either A: bad pump (not moving oil enough) or B: too large a passages for the oil to go through (worn bearing, etc) meaning that the VOLUME of oil going through the system is ectually HIGHER then normal because there is not a great deal of restriction on the flow of oil... So assuming an oil pressure failure is a result of "B" and not "A" and that the oil pressure is not so low that it is literally not getting forced into all the little crevices in the engine (as in like... Below 1 or 2 PSI) what is the problem?

I know I am wrong somewhere since everyone tells you that low oil pressure will damage your engine... So... Can someone correct my thinking on this?

[/hijack]

[RED-85-Z51]

My boss told me the same thing bascially today at work..."Dummy lights dont even come on until 6-7psi as it is, if you are getting 10psi, you're above the warning level at idle"

Im going to dump in a quart of 15W50 and see how the pressure reacts...