Overheating wont be fixed!!!

[chargerucd]

Hello guys, having an overheating problem.
11/2 years ago, I changed my radiator to mishimoto performance aluminum, the water pump, the thermostat, the hoses.

It ran fine until a month ago where it stared overheating.
Initially I thought it was the fan clutch because that was the one thing I didn't change before. So I changed it. Still overheats. This weekend I changed the thermostat and still overheats.
I notice that while I drive it is oveheats, but if I drive in lower gear and the car runs in high revs, it kinda cools down, but cannot figure out whatsoever happening.
Any ideas?
Thanks

[AZhitman]

Simple stuff first: Did you put the fan on backwards?

That'll create the problem you describe. Start the car, see if the fan is pulling through the radiator or pushing air forward.


Beyond that, check for:
Correct water pump?
Thermostat tested in a pan of water on the stove with a thermometer?
Thermostat installed in the correct orientation? (pointy end up, with the jiggle valve clocked correctly)?

However, I think the fan is reversed.

[Warren39]

You may have a head gasket problem or you water pump is not good
But, you changed radiator 11 years ago and that is a long time

[chargerucd]

Actually it was 1 and a half years ago,
But in the morning the starts up fine and goes up to temperature ok the thermostat opens fine, but then after about 10 minutes of driving THEN the temperature goes up, but it takes it about a minute to reach the max setting in the needle, then it just drops all the way back to normal temp. Them again it slowly goes up then drops fast ?!?!?!

I was thinking about hanging the water pump, but don't want to just keep changing parts without knowing.

Anybody seen this !?!?!?

Thanks

[chargerucd]

Ok,
So which water pump would be best for 240sx????

Any suggestions??

Thanks

[AZhitman]

Did you check the fan?

[chargerucd]

Hello,
Yes, fan is pointing the right way..
The car worked fine for almost 2 years then this happened.
But to add to my observations, if I go down the rodar at a lower gear, at higher revs, the car cools off but if I take a higher gear at lower revs, then the car heats up.
I got a new water pump and that is going in next. Well see.
Thanks

[chargerucd]

In a mad operation I changed the pump and removed the thermostat. Now, as expected, it takes a lot of time to warm up!
Choose, overheating too quick or long warmup? I ll choose long warmup.