Low oil pressure

[Skeew]

I got a d9g with a d353 engine, serial number 66a12365. We just rebuilt the engine and on startup we had low oil pressure from 8 psi to 22 psi. We put a brand new oil pump in and the oil pressure is still the same. Can the turbo oiler be the problem? The turbo oiler wasn't in the greatest shape when we put it back on the engine because it had been seized up When we took it apart. Turbo oiler is the only thing on the engine that we didn't replace cuz we have a hard time getting parts here in hawaii sometimes.

 

[Bls repair]

Check oil pressure with a different gauge?

 

[Skeew]

Yes we got another gauge and checked the pressure from a different oil port and both gauges agree with eachother

 

[Check Break]

Are the oil pumps CAT or aftermarket. If aftermarket, where were they made. I assume you traded the second pump for the first and no longer have the first. You'll have to measure up one of those pumps to determine if the pump was made to CAT spec-s, then work your way up looking for leaks.

 

[Skeew]

Are the oil pumps CAT or aftermarket. If aftermarket, where were they made. I assume you traded the second pump for the first and no longer have the first.

They are cat pumps. We still have the original and they are identical. Do you know if the turbo oiler got stuck, could it prevent the oil pressure from rising?

 

[Check Break]

I do not know the answer to your question. My knowledge base is limited to the D342, which is one size smaller, and inside which I would be looking for a leak long before the oil advanced to the turbo. If I were you I would go over to ACMOC.org (Bulletin Board Discussion Forum) and ask edb or Old Magnet for some help. Very smart guys with very good advice.

 

[Skeew]

So we plugged the lines going to the turbo oiler and made no difference with the oil pressure. We took the valve covers off and almost no oil getting to the rockers and lifters. We are thinking maybe it's the wrong oil filters or the tube from the pump to the filter assembly has a leak. That's the next thing we will check

 

[Delmer]

Unless you got fuel filters to fit, I can't see how an oil filter would make a difference. not too bad to check though.

What kind of pressure relief valve(s) does this have? that would be the first thing I'd check.

 

[DMiller]

You have excessive internal leakage going on such as Too much Mains clearance. Did you plastigage the bearings when overhauled? Were Cam Bearings replaced during OH? Did you put in what came out or just buy a basic kit? Sounds similar to a previous post that if do not stop running it will ruin it. An oil pump will not make up for Large Volume release pathways.

 

[DMiller]

IIRC the Head is lubrication fed off the Cam Gallery, if this is NOT getting oil to the head it may have a Spun or destroyed cam bearing or a covered passage in a cam bearing bore.

 

[56wrench]

check for leaks in any internal oil lines and fittings. if it was a bare block rebuild, is it possible there is a plug missing from an oil gallery somewhere inside or part of a relief valve is missing or stuck?

 

[DB2]

Pull the pan and put air pressure in the oil gallery to help find the leak. You don’t want to run it like that.
Anytime my dad rebuilt an engine one of the first things he did was check for oil at the top end.

 

[56wrench]

Ya, me too. I once checked out a top end noise in a little Ford 4000 tractor and found that previously someone had got the rocker shaft oil holes and rocker arms all out of whack and the rocker arms were running dry. It had been like that for years but not used much so no real damage. Just took it all apart and reassembled it correctly and made sure everything was getting oil, adjusted the lash and it was good to go. The top end was getting oil but it wasn't lubing anything

 

[Truck Shop]

Best way to find internal oil loss is to use a clean five gallon air tank and rig with one large npt bung for fill, a pressure gauge, hose and fittings. Plumb into main oil rifle
and check with pan off. If bearings are a problem you will see it gushing around journals or anywhere else. About 45 psi. Can make a big mess but the problem is visible.

 

[56wrench]

or use the fancy CAT or similar prelube can if you have access to one

 

[Old Magnet]

Get the side cover off the pan and check the suction bell screen.
If the oil pump comes from the "land of almost right" check gear to housing clearance and make sure the non-adjustable pressure control valve plunger is not sticking and the spring rating is correct. Should produce 45 psi
operating pressure.
Even if the oil filters are wrong or clogged it should run on by-pass and still give full pressure.
What have you got for bearing clearances?

 

[Skeew]

So we took off the oil filter housing and the tube from the oil pump to the filter housing was empty of oil along with the filter housing itself. Does the pump normally allow the oil in the oil galleys to flow backward through it and back into the oil pan when the engine isnt running? It seems like it should hold the oil and keep the filter housing and oil cooler full so it wouldn't have to re fill all that every time it starts?

 

[Old Magnet]

There are no check valves in the oil supply system. Back flow would be resisted by pump clearances to limit drain back but eventually over time the oil would drain back while the engine is idle. I would be checking pump gear to housing clearances.

 

[D6c10K]

On my 3306 the low pressure problem ended up being a combination of two things. The suction tube from the pan wasn't secured quite right and that allowed the tube to wiggle resulting in part of the gasket to fall out and suck air.
Secondly, the pressure relief on the pump was quite weak. The new one was way tighter. This was a belville washer stack type relief valve.

 

[kshansen]

or use the fancy CAT or similar prelube can if you have access to one

Do you have an air powered pump that you use to dispense oil? You could hook it to some point on the main oil galley and push oil in that way.