Oil Leaks After Rebuild, Normal?

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ThisIsSparTTa
Posts: 738
Joined: Wed Sep 26, 2012 6:02 pm
Car: 91 300ZX TT 2+0

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I recently completed my rebuild on my TT with all new gaskets, etc, and have about an hour of idling on it now troubleshooting some issues, and about 60 miles on it. It has probably been heat cycled 8-10 times now. If anyone followed my previous post, I didn't get it set up with the hard break-in in time for the event, so instead I am going for the slow break-in, although I have taken her out and run up and down 2-5k RPM in different gears, been doing lots of engine braking, etc.

So, I have oil, and possibly coolant leaking from a few places, and am wondering if this is normal. The reason I say possibly coolant is that I swear some of the liquids have a green-ish tint to them, but then they feel oily, so it may be coolant dripping onto oil leaking. My theory (and hope) is that it takes some time for the gaskets and RTV to really set in, and they need to get lubricated/wet and go through some heat cycles, especially the front/rear main seal rubber gaskets.

The places I suspect to be leaking from:
1) Oil: Front main seal or oil pump: Slight leak
2) Oil: Rear Main Seal: A good bit of leaking down and then onto transmission/exhaust when moving
3) Oil: Both Turbo Oil Return Lines into turbo: Very small
4) Oil: Oil return for turbo on side of girdle: Small from either side of copper crush washers: Image
5) Coolant: Rear hard coolant lines: Small

Is this somewhat normal? Should I wait it out a bit, or should I be concerned?


J30tChumpCar
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Concerned

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t.mcginley.jr
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Joined: Fri Jun 01, 2012 5:50 am
Car: 2002 Nissan Altima SE 3.5
1990 Nissan 300ZX NA 2+0
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Easiest way to tell what fluid it is, put white paper towels underneath the engine bay while it's idling and while its just sitting and then see what color the fluid is. And/or how it smells (coolant will be sweet smelling)

Is there oil running down the back of the engine from up top and down onto the trans/exhaust? Like is everything kind of coated?

ThisIsSparTTa
Posts: 738
Joined: Wed Sep 26, 2012 6:02 pm
Car: 91 300ZX TT 2+0

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Everything is coated from driving, but I don't really see any oil where I would consider "up top" which is around the hard coolant pipes. It seems to start around the bell housing and turbos. I've tried smelling it, but its tough to discern.

It's not leaking fast enough that idling would necessarily make it produce enough, but I do get a piddle on the floor after driving, and at that point its on the transmission and exhaust and other places.

J30tChumpCar
Posts: 487
Joined: Sat Jan 23, 2010 1:34 pm
Car: 1995 J30t Totaled @ Charlotte motor speedway
1994 J30 gutted caged road racer Now with VH45DE!
1966 Chevy Corvair V8 mid-ship conversion
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Contact:

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Clean and take for a shorter slower drive,reinspect before it gets everywhere, for tough leaks there is UV dye technique.

ThisIsSparTTa
Posts: 738
Joined: Wed Sep 26, 2012 6:02 pm
Car: 91 300ZX TT 2+0

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Yea, I may have to resort to dye soon. I've been cleaning up, but its still tough to locate. I've replaced my "short" oil cooler lines at the front, they were the brittle old rubber kind. I tightened the nut on the turbo oil return thing going into the girdle last night. I also think I found the source of one of my big leaks. I kept finding green liquid down the drivers side, finally I looked at it closer from the top of the engine and noticed my VTC was wet. I think somehow the coolant hose going from the heater core to the drivers side turbo was leaking right there (this is the routing after a plenum water line delete). I checked the hose itself, and it looked fine, but it was running kind of weird, so I moved it. I attached it back on with a screw-type clamp instead of the springy ones. If that fails, theres a chance the VTC may be leaking oil too which means removing that valve cover again. For the front of the engine, I have a slow leak near the front main seal or oil pump, but I think I know why. It's certainly not a problem like the stuff at the rear. I think I'm getting on the road to clear all these up.

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t.mcginley.jr
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Joined: Fri Jun 01, 2012 5:50 am
Car: 2002 Nissan Altima SE 3.5
1990 Nissan 300ZX NA 2+0
1966 Ford Mustang
Location: New Jersey, USA

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I had a similar problem on mine, that's why I asked if it was leaking from "up top" but I haven't checked the forum in a while. I did a full rebuild and ended up with oil all over the back of my engine and leaking onto the bellhousing and my exhaust. I didn't tighten the intake valve covers nearly as tight as they should have been and so it was leaking past the gasket and also past the silicone I put around the VTC solenoids. This time around I resealed the VTC solenoids with the copper RTF and made the intake valve covers good & tight. Some of the slow leaks aren't a huge deal, it only takes a few drops of oil spread over a big area to make it look like the engine is gushing oil.


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