Just for the record, electric fans have a long history of not working well on Z32s. Get a proper clutch-operated fan and shroud. Then, if it's still overheating, we'll talk about other sources of overheating.

The turbos are, as you suspected, water cooled, by the way. But I doubt that overheating turbos would cause the motor to overheat. The problem is clearly airflow, as is evidence by the fact that turning the heat on will help. The heater core acts as a second radiator when it's on... so clearly, if the car is overheating when the heat is off, the radiator isn't doing its job... and based on the electric fan, I'll bet that's because it's not getting proper airflow.

 

I swear I said before. the oem engine fan is still in place, but the aftermarket radiator they put in wont let me use the shroud. even if I had one. And dont all Z32 have an electric pusher fan to start with? I just put a fan where one should have been to start with.

And it was still overheating before I put the pusher fan on. Maybe I should take a picture of what is under the nose cover.

 

On this last pic you can see the small oil puddle under the Ic boot.

And this is this annoying 300ZXTT I've been working on.

 

There is a fan in front of the radiator/condenser that operates almost exclusively when the AC is on. It is not relied upon for maintaining engine temps.

You absolutely need to figure out how to get a shroud on there. A fan without a shroud will draw air from the wrong places... i.e. not past the radiator.

And from the pics, that car is ****ed. Burn it, file an insurance claim, move on. lol

 

Ok thats news to me.

And I'd love to. if I could. I know it wont fit behind that radiator. that fan scares me with how close it flexes to the radiator to start with.


thats what I wish I could do lol Er take the seats out first for my 280Zx tho

 

You know, one of the little tricks we do in the racing world is drill a small hole into the rim of the thermostat to increase coolant flow through the system. Even when the thermostat is closed, it'll flow a little more than it naturally does (it has a small flapper to allow some flow to begin with), thus lowering the temps. If you want to dig in, you can try that. It won't solve the problem, but it couldn't hurt and might help.

But I do think the issue is not getting air through the radiator. If everything else is new and installed properly, the lack of a shroud is the only thing that stands out to me. Search twinturbo.net to see what people have done about upgraded radiators - I've only ever needed a stock one, so I don't know what they do about their shrouds.

 

I'll try that then.

And I'll look. Hmm did the TT have a 1 core radiator? My friend gave me the "spare" one and its a tiny thing compared to this monster.

 

Ok well theres no T stat at all.

I know the pump is new, radiator is clean, caps is new, lines are new, and I think theres no clogs.

Hmm anyone got a set up upper radiator mounts and the fan shroud? I'm gonna put the 1 core back in. If it shouldn't overheat with that. then theres no way this like 3 or 4 core radiator should even been getting this hot. Even with both fans on it.

On the off chance it ISNT the fan shroud or air flow. What else could do this? blown headgasket?

 

Well is it maintaining the fluid level or are you losing fluid? The only way blown head gaskets would cause it is if the fluid is entering the cylinders and being burned off, thus reducing the amount of liquid available for cooling purposes.

And you need a thermostat. You said it had a new thermostat... were you lying or were you trusting what the previous owners told you?

 

I remember putting one in when I had the engine pulled. I'm guessing the owner thought otherwise and took it out afterwords....

And no its not loosing coolant or anything.

 

I thought of putting my shop fan right into the air box cover so a ton of air would be blowing though the rad. An I put a brand new T stat in and tested that beforehand to make sure it worked. Still overheats to 3/4 the gauge. I'm at a total loss now. And I looked inside the rad to make sure the water was flowing and it is.

Fresh Coolant with that royal purple additive, Flushed out and cleaned radiator, all new lines, new cap, new Water pump, and Tstat. Good pressure, no visible leaks and with good airflow as well.

And the timing and fuel pressure is good as well. along with it being at the right level for oil

 

... if it goes up to 3/4 of the gauge, I have to ask... are you properly burping the cooling system? (i.e. Lift the front end of the car, remove radiator cap, run engine and allow air that would otherwise sit inside the engine to escape, adding fluid until it overflows.)

 

Yes. I took both the cap and that bolt off so all the air would get out.

I find it weird I can let it idle for pretty much ever and it will never overheat but as soon as i start driving it it goes all the way up to 3/4 then if I let it idle again it will climb much further past that.

 

... bolt?

And once again, are you doing this with the front end of the car elevated?


How is the airflow to the radiator? Is the AC condenser all backed up, maybe, blocking airflow to the radiator?

 

Look at the pics on the top of the rad on the passenger side. And yes

AC is all long gone. That was done around the time of the engine swap. An the fins of the rad are all clean.

 

I'm gonna take a shot in the dark and say theres a clog somewhere inside the block. thats the only thing I can think of

 

Don't forget to turn the heater on to the highest setting so that coolant can flow thru the heater core too.

 

I didn't even think about that, I'll try that tomorrow and see what happens.

 

K I burped it again and only had to add a little bit. but it still wants to overheat.

But I forgot to mention that when I put the new T-stat in, everything has a dark rusty red color on the inside. I wonder what life this JDM engine had before it was pulled and put into this US car. The radiator never had this red color in it I remember.

 

... did you never flush the system? You talked about all the work you did (most of which requires coolant replacement), but all the sudden there's unknown fluid in the system...

I'm sorry, but I'm beginning to question your mechanical knowledge, now... lol Most different coolants aren't compatible, so you may have caused a blockage by not flushing the old crap out... that's why flushing is necessary with motors of unknown origin.

 

I drained it, flushed with water a few times, drained it entirely and refilled with a 50/50 mix of green coolant and water then the Royal purple additive on top of that. I'm not an idiot. Mind you this thing as always been overheating according to the owner, and I'm sure I've said this before.

I never said there was unknown fluid. I just said all the walls on the inside of the T-stat housing has a rusty red stain all over the inside.

 

Well it doesn't matter now. I burped it again and while I was going so the coolant dropped, the engine started stumbling and there was a sickly sweet smell in the air, along will bubbles coming up out of the radiator. All that heat finally blew a head gasket.

 

It might've been having HG problems the whole time... that motor needs a refresh BAD anyway, from the sounds of it.

 

I'd agree with you. Well its a good excuse to fix this motor right for once, but I think the owner is just gonna scrap the car. We'll see what happens.

 

How is the body?

If they are literally thinking about taking the car to a junkyard, let me know... I might be in a position to offer them more than a junk yard will.