Fresh rebuild, no oil pressure and major leak

[paw140]

Hi All,

I'm a little bit puzzled and wanted to see if anyone had any thoughts. I'm just about wrapping up my engine rebuild in my '69 S4. Yesterday I tried to get oil pressure by cranking with the plugs removed but was unsuccessful. I've read on this forum from multiple folks that this can be an issue and several have suggested just starting the engine. So I did that this afternoon. It started right up and ran for about 10-15 seconds before I shut it down because I wasn't seeing any pressure on the gauge. Then I noticed a substantial oil puddle under the filter / pump area. I'd estimate maybe 4 to 6 ounces leaked onto the floor... it was a major leak. I put the car on jack stands and crawled underneath and it looks like it is coming from the sealing area between the filter and pump... like the filter wasn't tight enough. But it was pretty tight and I removed it to inspect it and I don't any issues with the gasket, pump housing surface, etc. It is a Fram PH2870A. I removed the oil pressure gauge fitting and there was definitely oil that made it's way into the galleries, so it must have had some pressure. I also have installed a pressure switch to drive my fuel pump and that was activated, so it generated at least enough pressure to trip the switch.

At this stage I'm a little unsure how to proceed, because I don't want to run the engine again unless I am sure I will get oil pressure. I'm wondering if it's maybe something as simple as a loose oil filter? It definitely wasn't 'loose' but maybe it was bottoming out on something other than the gasket? The oil filter and gasket look perfect. Is there any other reason why it would leak through the gasket area... overpressurizing? But there is a pressure relief valve to pump oil back into the sump, correct?

I'm contemplating buying a new filter (not a Fram! any recommendations?) and trying again. My guess is that it is something simple like a defective or ill-fitting oil filter, but wanted to see if anyone else had other thoughts.

Thanks!

Paul

[mbell]

Are you sure the gauge is operational? Have your another one you could test with?

I normally prime the system by pump oil in his the pressure take off connection.

But there is a pressure relief valve to pump oil back into the sump, correct?

Correct. It's a cylinder on the under side of the pump above the filter. Probably with checking it's operation by using screw driver to open it a bit and check it costs again.

not a Fram! any recommendations?

Mobil 1 m1 205a extended performance. If you can find one at Walmart they reasonably priced. A bit pricier from the car part stores. But well worth the extra imo.

[2cams70]

You are correct - don’t whatever you do attempt to restart the engine without identifying the cause of the problem. Don’t bother trying to crank it to get pressure either.

How did the filter feel when you tightened it? Did it stop turning suddenly or was half to three quarter turn still possible after the rubber gasket contacted the pump body?

[paw140]

mbell - my stock pressure gauge does tend to stick a little (it is not smooth), but today I removed the pressure line and applied 20 psi of air pressure to confirm that the needle moves, and it did move. I have considering buying a new gauge just for troubleshooting this issue to eliminate the possibility of a faulty gauge.

2cams - I just went to my garage and reinstalled the oil filter and it tightens up perfectly like you would expect... the once the gasket bottoms out you can easily get 1/2 turn to crush the gasket. I can't eliminate the possibility that I somehow messed this up the first time.

[2cams70]

The other possibility is that it has nothing to do with the filter. It may in fact be leaking at the pump to block gasket. In that location it is difficult to separate one from the other. I’d suggest removing the pump and checking the gasket. If it’s a new repro pump I’d be checking for cracks in the casting too. Did you tighten the pump bolts properly and did you use the correct length bolts?

[rgh0]

I would check the pump and filter to confirm no issues. I would fill the oil filter with oil and put some assembly lube on the pump rotor. I would then fill the engine passages with oil using a hand pump bottle or pressure bottle through the block pressure sensor port.

Once all this is done then crank the engine with the plugs out will get you pressure almost immediately in my experience

cheers
Rohan

[2cams70]

Don’t bother with random stab in the dark things like using assembly lube and filling galleries. That’s not the problem. You need to take apart and observe. You don’t need anything but standard engine oil on the pump rotors.

[rgh0]

Don’t bother with random stab in the dark things like using assembly lube and filling galleries. That’s not the problem. You need to take apart and observe. You don’t need anything but standard engine oil on the pump rotors.

I agree as I said that you need to dismantle and inspect the oil pump to ensure it is correctly assembled with no issues such as a jammed pressure releif valve or worn rotors. The use of assembly lube and filling the oil galleries etc I just consider best practice to minimise the period the engine runs without oil on the initial start up. It is not a random stab in the dark to try to solve a pump priming problem

cheers
Rohan

[paw140]

Thanks for the suggestions everyone. Here is my plan... I'm buying a new oil filter and will fill that and install it. I'll then hook up a pressurized oil bottle to the pressure gauge connection and pressurize the system with oil to check for leaks (as well as fill the oil galleries). This is the only way that I can think to check for leaks without starting the engine and risking damage.

The oil pump is new... if you have followed my saga, I bought this car from a friend 3 years ago and it was completely disassembled. Seats, dash, switches, engine, transmission, pretty much everything was taken apart. But he insisted on 'rebuilding' the engine and getting it put together before I took delivery of the car. I should have known better than to trust his work. I did get the car running but it smoked terribly and had really low compression (120 to 140 psi). Over the past few months I pulled the engine and discovered that he used a grinder to smooth out the cylinder walls where the pistons had seized from sitting for 30 years, so there was no way the rings could ever seal. I've had it bored out 40 thousandths, new pistons, bearings, etc. I had replaced the oil pump originally and it worked fine then. I did not take it apart during this last rebuild, and it's obviously pumping so i don't see any reason to take it apart.

[joe7]

Had the same problem after an oil change. I used Fram filters forever BUT for the new ones I bought the part number was changed. Filled filter, installed, started up no oil pressure. Took the other new one I bought and attempted to blow through to ensure the bypass valve was opening. It wasn't, so no oil was coming through the filter. Bought a NAPA GoldPro. Blew through it and could easily tell the valve was opening, you can actually hear it. Filled filter, installed, turned key, immediate oil pressure.

[USA64]

While we're on the subject, do filters have a shelf-life?

[david.g.chapman]

I'm sure you have checked this, but just in case.... sometimes a new oil filter has a clear film cap which has to be peeled off. If you didn't fill the filter and just screwed it on quickly (as I usually do)... maybe?

Dave Chapman.

[paw140]

Hi David,

No plastic film... it prefilled it before installing it. I'm still baffled as to what happened and cannot think of a scenario that would cause such a massive leak between the filter and pump housing. I've done many oil changes in my life and never had an issue like this.

I should have more info sometime this weekend when I get the new filter and have time to investigate... will update.

Thanks,

Paul

[david.g.chapman]

Good luck Paul....

Dave Chapman.

[h20hamelan]

you forgot the old oil ring
oil filters, canister have O rings on top, sometimes they stay lodged onto the housing.
I am sure this is the case here, do you have the old filter, or take the new one off and examine.