engine and drivetrain Rebuild, Oil Pressure, Then None. Ideas?

[brendang2000]

Just freshened up an old 318 motor, swapped pickup for the 02 and primed on stand to 20psi with starter. Oil making it to the cam oil tube. Everything looked good. Installed in car, got it running, very low pressure at idle, getting lower, getting lower, zero pressure. Pulled valve cover, no oil to cam. Dropped oilpan in car to make sure pickup still attached and pump shaft spinning. I know the 2 O-rings were in there, I did not replace for new, but maybe I nicked one while installing? I read a post about the bypass valve sticking, but wouldn't that just bypass the filter and not drop pressure? Metal gasket was installed between pump and pickup. Any ideas, anything I'm missing? Looks like I'll be pulling this engine. Thanks.

[allbim]

I don't know what your problem is, but  you should be able to get 50 PSI plus, when cranking with the starter and the plugs removed. The bypass valve routes oil from the main delivery bore back to the intake of the pump and the pan, after it has passed through the filter. It does not bypass the filter. 

[brendang2000]

Thanks for the diagrams, it gave me a little more understanding.

So I did some testing. With the motor on a stand I was again able to get 30lbs by turning the pump with a drill, but oil started coming out of the pressure valve, 3a in the diagram. I pulled the pump and the piston was stuck down in the tube and I had to use a punch to remove it. I cleaned the bore as best as I could and got the piston to move freely again, but when I assembled it, it stuck again. It seems to be catching on the oil passasge about halfway down the tube. Done with that pump.

Next, I pulled the pickup and installed on an older style pump (3 bolt pully), and this one has no oil pressure at all, it's not even sucking up oil!!! I looked down the pickup, and there is no blockage, so I have no clue what is going on here. I'm very frustrated and hope someone has some insite as to what I should try next. Thanks

[Guest_anonymous]

did you install the pump dry or did you put it together with some vaseline to start the prime on the pump? Was the second pump rotor components within specification? It is expensive for a new pump but it is less expensive than starting over

[brendang2000]

I didn't check tolerances as it came out of a running car, and it's not a keeper as the rotor had some junk go through it at some point and scratched everything up. I just wanted to verify operation of the rest of the system with this pump. It's been cleaned to make sure there was no metal left to contaminate the system. The internals were covered in oil but not Vaseline on installation. I'll try some assembly lube to prime it.

Yea, the price of a new 02 pump is hard to swallow. I'd gladly pay the $200 for a new E30/318 pump, but I think they went to a newer design and I won't be able to swap pickups. Dreading selling a kidney for the 02 pump.

[brendang2000]

Daron, was that a re-grind cam?

[Guest_anonymous]

yes. before and after

might want to take a look into the oil filter and see if any high pressure started to collapse the element before the relief valve jammed. no sense in sending that through the engine. But it seems from your sequence that the pressure relief valve might have been jammed prior to assembly from the previous build.

Edited July 14, 2014 by daron_in_

[allbim]

You can by individual pump parts at http://www.penskeparts.com/DiagramsMain.aspx?vid=47140&rnd=03192010

Edited July 14, 2014 by allbim

[brendang2000]

yes. before and after

might want to take a look into the oil filter and see if any high pressure started to collapse the element before the relief valve jammed. no sense in sending that through the engine. But it seems from your sequence that the pressure relief valve might have been jammed prior to assembly from the previous build.

I did check and the filter looked fine, and I think the valve was jammed prior to my install, wish I would have noticed this before installing:/

[peterschop]

Just a thought but is the metal shim between the pump and block installed with the oil passage hole on the correct side?

[brendang2000]

Just a thought but is the metal shim between the pump and block installed with the oil passage hole on the correct side?

It was. At first I thought I screwed that up, but it was installed correctly. I was able to find a used pump in town, so hopefully I won't have any issues with this one. Thanks for everyone's help!