Riddle Me This? Random Overheat

[greencar]

The basics:

92 240sx with stock internal ka24de, 16,000 on rebuilt motorE-Fans with DIF controllerCX Racing Aftermarket radiatorAutometer Temp Gauge

The car has a new Nissan OEM thermostat, a relatively new H20 pump, and hoses.

I have bled this car many times when it was bone stock.. my radiator clutch fan popped the radiator and this is what warranted the new set-up i have now.

For the life of me, it would warm up but as soon as I drive it, the temp would shoot up instantly.

I decided to drill a hole in the thermostat (7/16) it ran fine after that but would only stay in the 120 degree range.

I put in a new thermostat with a 7/32 hole and it is now randomly overheating again..

I can drive around town, but if cruise at a constant speed, or I get on the freeway the temps start rising. If i turn on the heat.. it starts to go down. But sometimes with the heat on the temps dont lower.

I believe that the aftermarket cooling set-up is too efficient. the cold air in front of the thermostat is too extreme for the hot water behind it and it will not open up. Am I crazy here?

Any suggestions Niconaughts?

[Klits562]

Are you losing any coolant?I dont think the air is to cold for the thermostat seeing as no air should be hitting your thermostat as its in a thick housing.Have you made sure that your e fans are working? And are they wired to suck and not blow?

[OutToWinPAHC]

Not bashing, but those radiators are cheap with bad welds, so it sould be letting air in. I would also try an OEM / Nismo / greddy / koyo radiator cap.

Bleed with heat on for a long time and a very good incline. And try some good ole redline water wetter

[greencar]

I'm gonna revert it all back to OEM everything except for the fan set-up, gonna run the E-fans still.

I'm not loosing any coolant, and the Fans are wired correctly (to suck)

-Dan

[Cone Junky]

My buddy's car had the same symptoms for over a week after he did his water pump/t-stat. It would randomly overheat, especially on the freeway, and he had to keep adding coolant.We assumed head gasket and were just waiting for a good time to tear it down. But it finally bled itself and has been trouble free for a month now.

In other words, it probably just needs to be bled still.

[Duce40sx]

The basics:

92 240sx with stock internal ka24de, 16,000 on rebuilt motorE-Fans with DIF controllerCX Racing Aftermarket radiatorAutometer Temp Gauge

The car has a new Nissan OEM thermostat, a relatively new H20 pump, and hoses.

I have bled this car many times when it was bone stock.. my radiator clutch fan popped the radiator and this is what warranted the new set-up i have now.

For the life of me, it would warm up but as soon as I drive it, the temp would shoot up instantly.

I decided to drill a hole in the thermostat (7/16) it ran fine after that but would only stay in the 120 degree range.

I put in a new thermostat with a 7/32 hole and it is now randomly overheating again..

I can drive around town, but if cruise at a constant speed, or I get on the freeway the temps start rising. If i turn on the heat.. it starts to go down. But sometimes with the heat on the temps dont lower.

I believe that the aftermarket cooling set-up is too efficient. the cold air in front of the thermostat is too extreme for the hot water behind it and it will not open up. Am I crazy here?

Any suggestions Niconaughts?

Why would you drill a hole in the thermostat????GO BUY a factory nissan one, your new thermostat is probably defective.

A water pocket will not cause your car to overheat. A water pocked from not bleeding correctly will make your water temp sensor jiggle and vibrate.

There are a few factors why your car is overheating.

1. The CX radiator is defective. These China radiators have manufacturing defects in them. Common with Megans, Mishimoto, CX, XS, Circuit sport, griffin, etc.

2. Your thermostat has an issue. Your car usually overheats because the water in the block can't exit and the sensor on the block picks this up, and needle rises. Coolant stays in engine at optimum warm operating temperature, once it's is too hot, the thermostat will open and water circulates. So overheating usually has to deal with thermostat. (Maybe you could have installed it backwards?)

Those are the ony two major defects I would think of because 9/10 times, when I change to a new OEM Factory Nissan thermostat, it fixes the problem. At $15-20 bucks. If you changed it recently, make sure you didn't get RTV silicon all over the thermostat.

[sr20671]

Or your water pump/belt might be failing due to either the pumps slipping on the belt or it's losing it's ability to circulate the coolant effectively

[godzilladrift240]

may sound dumb but ive seen it before, make sure ur thermo isnt in backwards