She's Alive but leaking oil

[Mike Nance]

After all the excitement of getting the 1974 Tii to start, it is leaking oil at the filter housing/oil filter gasket only while running. While setting the timing which went well I noticed a small puddle of oil on the ground underneath the oil filter, with lots of spray on the alternator. I filled the engine with 20W50 and new oil filter yesterday before setting the timming. I suspected the oil was to thick so I changed the oil to 10w30 and a new filter which did not help, still leaking at the oil filter/housing seal. I observed spray from the bottom of the filter housing/oil filter gasket which comes around 15-20 deconds after starting the motor. The motor was rebuilt a few years ago but it never ran until yesterday. Am I looking at a bad oil pump, pressure relief valve install, blocked oil passages? I'm stumped. The oil filter housing gasket isn't leaking, its bone dry,  the dip stick rubber hose connection is good.  I guess i will need a new oil pump. 

 

Any help or ideas identifying the problem would be great.

[Tommy]

Does it push out the filter seal or how is it leaking? If the ring is pushed out it's probably stuck pressure relief valve. If it's on place but still leaks the sealing surface on the filter head could be damaged.

[Mike Nance]

@Tommythere was a rough edge on the top of the filter housing. I sanded that smooth with 800 grit paper thinking that was the problem. No joy after that. Pressure relief valve is what I’m thinking. Does the engine really need to be pulled to remove the oil pan?

[Tommy]

10 minutes ago, Mike Nance said:

Pressure relief valve is what I’m thinking. Does the engine really need to be pulled to remove the oil pan?

No, not completely but you have to tilt it somehow or lift it a bit to get the pan past the oil pump pick-up. I think I've done it years ago but can't remember details.

I had a similar issue once when I did some work on a friends car. I assembled the relief tube wrong way and it prevented the piston movement. Oil pressure was high enough to bend the face of the filter and the seal got pushed out. It was easier fix as the car was e30 with 2 piece oil pan. I have heard the relief piston sticking even in brand new pumps. They just need some honing to move freely.

[Mike Nance]

@Tommylooks like a busy day for me. I have a spare oil pump from a 1976 non Tii engine, do you know if they are the same part number? Real OEM isnt clear on any differences between a Tii oil pump and standard oil pump.

[Tommy]

No there shouldn't be any difference. Over the years there were some changes in pumps so all the parts are not always interchangable but whole pump should fit.

[OldRoller]

Verify the actual pressure with a wet gauge at the sender by the distributor. At 100 psi + your relief valve isn't functioning.

Below 100 you might have a damaged filter housing, had one recently with the center threaded filter adapter bent, casuing uneven pressure to the filter seal....

[Mike Nance]

@oldroller which gauge should I get?

[Mike Nance]

@OldRollerI picked up an oil pressure gauge and I’m running at a low pressure at idle approximately 850rpm of 60psi at 3000rpm 80psi. If it isn’t the pressure relief valve, I guess it is an oil filter housing issue. I added a video to show the drips

 

 

[Tommy]

With cold oil those are reasonable firgures.

[Mike Nance]

@Tommyagreed. The leak starts quickly after startup. Around 20 seconds after it’s started. Very confusing. 

[TobyB]

So it's blowing past the oil filter rubber base seal?

 

Occam says it's the oil filter, and further diagnosis might condemn the filter base.

 

The pressures are good, and what you'd want with a fresh engine.

 

From experience with a stuck regulator, it doesn't cause trouble until you hit 4k,

and then you'll take several hundred PSI to blow that seal.  And it will extrude itself

from the channel in the filter housing.

 

Oh.

 

Have you made sure that the filter seal is firmly seated against the filter base?

Made sure the seal's not deformed?

Made sure the housing base isn't deformed, or has some debris in it?

 

t

 

[bergie33]

And make sure to oil the seal before installing the filter.

[Mike Nance]

@TobyBthe oil filter housing face is smooth no inclusions or debris. Same for the 3rd filter I’ve tried. We see oil blowing around the oil pan seal and it just below the oil filter and are thinking the oil just happens to be blowing into the oil filter making it look as though it’s leaking there. So we are just going to replace the gasket on the oil pan for now and test it again. 

[bergie33]

There shouldn't be enough pressure to blow out the side of the oil pan.  The oil pan is unpressurized.  Oil pan leaks are usually a result of sloshing oil, not pressure.  I had a similar problem with my Dodge Dakota, the old oil filter seal was stuck on the housing and I didn't realize it. Make sure you didn't have an old seal still in there.