Built Engine - Mysterious Oil Leak? Front Of Motor

braydo25 · 07-04-2018, 01:06 PM

Hey guys, I have a twin turbo 370z with a built motor that has about 2,000 miles on it or so.

I'm starting to get a decent oil leak from the front of the engine somewhere - it's enough where after 50 to 100 miles of driving there's oil residues all down the bottom / underside of the car.

I can't seem to see where it's coming from as the timing cover is painted black.

I thought it was the front main seal, but it seems it's maybe coming from higher than that, as there's dirt / grit build up on the cover above it which I presume is also from the oil - it's also possible that the pulley is slinging oil up if it is that..

My skid plate looks like it has a spray of oil film on it, so it's possible oil is somehow hitting either radiator fan and getting thrown around, or dripping onto crank pulley and being thrown around.

I was able to look at the valve cover gaskets and those seem fine. Is there anything else on the front timing cover between the front main seal and the valve cover gaskets it could be that I should check?

Spooler · 07-04-2018, 01:22 PM

Yes, there are seals between the back of the front cover and the block and heads. One goes in between the block and supplies oil to the front cover oil galley areas. You also have the oil filter area on the passenger side of the motor. You will need to clean it all up extremely well and then see if you can find it.

Quicksilvers · 07-04-2018, 11:33 PM

Yes it is possible your mysterious oil leak may be coming from somewhere in the oil gallery area. You will need to clean the whole area as best as possible and then let it leak and then try to diagnose the oil leak that would be best.

braydo25 · 05-05-2019, 03:48 PM

Ended up being a loose A/N fitting that was a quick fix for anyone curious.

07-04-2018, 01:06 PM	#1 (permalink)
braydo25 Base Member Join Date: Apr 2012 Location: Tacoma Posts: 67 Drives: Nismo z34 Rep Power: 13	Built Engine - Mysterious Oil Leak? Front Of Motor Hey guys, I have a twin turbo 370z with a built motor that has about 2,000 miles on it or so. I'm starting to get a decent oil leak from the front of the engine somewhere - it's enough where after 50 to 100 miles of driving there's oil residues all down the bottom / underside of the car. I can't seem to see where it's coming from as the timing cover is painted black. I thought it was the front main seal, but it seems it's maybe coming from higher than that, as there's dirt / grit build up on the cover above it which I presume is also from the oil - it's also possible that the pulley is slinging oil up if it is that.. My skid plate looks like it has a spray of oil film on it, so it's possible oil is somehow hitting either radiator fan and getting thrown around, or dripping onto crank pulley and being thrown around. I was able to look at the valve cover gaskets and those seem fine. Is there anything else on the front timing cover between the front main seal and the valve cover gaskets it could be that I should check?

05-05-2019, 03:48 PM	#4 (permalink)
braydo25 Base Member Join Date: Apr 2012 Location: Tacoma Posts: 67 Drives: Nismo z34 Rep Power: 13	Ended up being a loose A/N fitting that was a quick fix for anyone curious. elhombre likes this.

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07-04-2018, 01:22 PM	#2 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,834 Drives: 2013 Nismo 370z Rep Power: 2684392	Yes, there are seals between the back of the front cover and the block and heads. One goes in between the block and supplies oil to the front cover oil galley areas. You also have the oil filter area on the passenger side of the motor. You will need to clean it all up extremely well and then see if you can find it.

07-04-2018, 11:33 PM	#3 (permalink)
Quicksilvers A True Z Fanatic Join Date: May 2017 Location: Atlanta, GA Posts: 2,039 Drives: 2017 370z Rep Power: 25463	Yes it is possible your mysterious oil leak may be coming from somewhere in the oil gallery area. You will need to clean the whole area as best as possible and then let it leak and then try to diagnose the oil leak that would be best.