Coolant leak above drivers side turbo/Steam after driving

Nissan 300ZX technical discussion forum: Maintenance, performance, installations, modifications, how-to's and troubleshooting.
Blurr
Posts: 112
Joined: Fri Apr 23, 2010 2:48 am
Car: 1990 300zx Twin Turbo JDM Motor Swap

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k... so in an effort to find out where the mysterious leak is coming from, it looks like its coming from one line out of the firewall.

Whats strange is, it only happens sometimes. Not all the time. I drove to get gas just now, down the street and around the blocks, came home, popped the hood and nothing. No steam, no drip. The other day running it around down the street, same vicinity, I had steam once I parked.

I dont know what this line is, can you guys help identify? Id like to take it off and replace it seeing as its the only line thats showing signs of leaking. It is right under a bigger line on the drivers side. Where the drip is coming from its too far back to be the intake manifold, or valve cover gasket.

I suspect the hose thats leaking coming out from the firewall to a metal pipe.

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I do see oil on a screw back there, which is kinda where the valve cover gasket corner is so i know its possibly seeping some there but not horribly bad.

Since I put 20 bucks of 91 gas in it, bogging seems to have disappeared so its making me think maybe it was just low on gas. Do these cars have a warning light when the gas is low? I was running on E for a long time before pumping.

Im trying to rid the car of whatever old gas may be in it as I suspect 89 was used before cause of alot of problems prior.

Heres a look at some of the rework I did, cleaning up the engine. I took the balance bar off, and repainted it aluminum smoke, which is kind of a dark, titanium color. Motor looked 100000 times worse than this when I got it.

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evildky
Posts: 14225
Joined: Sat Jan 31, 2004 9:23 pm
Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW
Location: Louisville, KY
Contact:

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it's one of the plenum or turbo cooland lines leaking, this is why so many of us bypass the plenum hoses, there are a buch of tiny coolant hoses under the pllenum taht go to the TB's and turbo's, one of them is leaking, you now get to take it all apart to find which one ;)

and I like your timing ocver paint FWIW

Blurr
Posts: 112
Joined: Fri Apr 23, 2010 2:48 am
Car: 1990 300zx Twin Turbo JDM Motor Swap

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thanks evil. Ill take a look at it later today so I can get a better idea of which one it is. it does look like it goes to something inside the firewall, which is making me suspect that it may be a heater hose or something. But if the coolant lines are above the turbo, going to a metal pipe of some sort on the block then thats probably it also.

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evildky
Posts: 14225
Joined: Sat Jan 31, 2004 9:23 pm
Car: 71 Datsun 240ZT
87 Nissan 300ZX N/A-T
06 Nissan 350Z GT
Toyota Tundra TRD RW
Location: Louisville, KY
Contact:

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the 2 heater hoses are int he middle and wouldn't be dripping on the turbo's, the only hose going through the firewall ont he drivers side is the vac hose to the clutch master cylinder booster which is located inside the car

Blurr
Posts: 112
Joined: Fri Apr 23, 2010 2:48 am
Car: 1990 300zx Twin Turbo JDM Motor Swap

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So running tonight over to the local library, it was a bit chilly out, so I kicked on my heater to about 80. Got home, let the turbos cool and shut my car off. Wala, ala steam comes rising outta the same spot.

I ran the Z to SF last weekend, about 60 miles out, didnt turn on my heater, or vents, and no steam when I got home. So, looks like the coolant leak is definitely those two hoses.

Question: The heater hoses I see on Z1 are the ones im suspecting to be bad. Im thinking of getting the set, since Im replacing one, might as well replace the other right? How difficult is this going to be, if I don't have a lift, and the engine is still in? By the looks of the photo below, looks like the engine is out.

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Any idea on an estimate on how much a shop would charge for this job?


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