Close to overheating problem!

V

vbgambini

Member
This is for my 1998 240sx 1JZGTE (Chaser). My car starts to get close to the H on the thermostat when im on the highway. When im city driving it seems to be fine but still running a little hot. I have a FM and also a condenser for my AC so im guessing my Mishimoto radiator is not getting enough air. I also have two fans pulling on the radiator. Any ideas for better flow? Or get my car to run cooler?? Any help would be appreciated. Thanks guys!
 
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Have you ever seen in person a I6 swap in a S chasis before?


To the OP what fans are you using?
 
Did I come to a good conclusion of why it is close to overheating? Fans are definitely working. A shroud would be tough due to the amount of space available. Cooling plates? Air ducts? SMIC an idea??

Mishimoto Radiator/Cap
Murrays dual electric fans
 
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make sure you have a good seal around between the condenser and radiator. the air could be dispersing around the radiator instead of through it at high speeds. also how are you fans hooked up. behind radiator pulling air or in front of condenser and pushing. are fans wired low speed only, high speed only, etc
 
yes i have seen it but im not saying to put a big ass shroud in. but there are shroud that are thin enough to get the job done. something like this [ame="http://www.amazon.com/Mishimoto-MMFS-WRX-01-Fan-Shroud-Kit/dp/B002CXGBH4"]Amazon.com: Mishimoto MMFS-WRX-01 Fan Shroud Kit: Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41beVml535L.@@AMEPARAM@@41beVml535L[/ame]
 
I mean it is a stock condenser, how would the seal not be as good? Fans are located behind the radiator pulling to the motor. Fan speeds are unknown, seems like one speed. Would a colder thermostat help? Not sure whats in there now.
 
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All wrong fans are not needed at any highway speed. PERIOD!! Are you overflowing the catch tank or bottle? I would look towards a bad waterpump, t-stat or headgasket issue.
 
Sounds like weak water pump. City driving is low rpms and sitting at idle. Highway is a constant high rpm. At highway speeds its not radiator getting enough air...its the freaking highway. It's that cool liquid not going through the engine before it gets to hot. To test this theory yourself just unplug the fans on the side of the highway and drive. You won't notice any difference so lack of air is not the issue.

But then again ppl call me crazy so take my advice on your own regard

Sorry for those who don't understand...higher rpms mean engine is working harder and that means producing more heat. That's why he has a bigger problem on the highway.
 
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crayZwhiteboy said:
Sounds like weak water pump. City driving is low rpms and sitting at idle. Highway is a constant high rpm. At highway speeds its not radiator getting enough air...its the freaking highway. It's that cool liquid not going through the engine before it gets to hot. To test this theory yourself just unplug the fans on the side of the highway and drive. You won't notice any difference so lack of air is not the issue.

But then again ppl call me crazy so take my advice on your own regard

Sorry for those who don't understand...higher rpms mean engine is working harder and that means producing more heat. That's why he has a bigger problem on the highway.
Click to expand...

huh?

That doesn't make any sense...

To the OP, you should be running cooler on the highway. Your at high speed and wind forces straight into your radiator. Your issue could be what has been already mentioned above; i.e: water pump, t stat, low coolant, HG, or air bubbles in your system.
 
Have you changed any of the pulleys?
I know the SR's have water pump cavitation problems at high rpm.

I would start with ducting.
It will be the cheapest most effective mod you can make.
Top, bottom and sides.
Anywhere the air can escape and bypass the rad.

If you have the "JDM" hood spacer mod.
Ditch it and fix your hood.

Make sure you've bleed your system properly.
Have you flushed your system

Go to autozone and pick up a flush kit.
Very easy to use.

If these don't help then maybe you have a bad sensor.
 
Chigga311 said:
Have you changed any of the pulleys?
I know the SR's have water pump cavitation problems at high rpm.

I would start with ducting.
It will be the cheapest most effective mod you can make.
Top, bottom and sides.
Anywhere the air can escape and bypass the rad.

If you have the "JDM" hood spacer mod.
Ditch it and fix your hood.

Make sure you've bleed your system properly.
Have you flushed your system

Go to autozone and pick up a flush kit.
Very easy to use.

If these don't help then maybe you have a bad sensor.
Click to expand...

Pulleys haven't been changed.

Ideas on how to start air ducts? Aluminum sheets? Anyone with A DIY or any pics of set ups?

No JDM spacer mod.

Might need to flush system.
 
BILLFISHER21 said:
All wrong fans are not needed at any highway speed. PERIOD!! Are you overflowing the catch tank or bottle? I would look towards a bad waterpump, t-stat or headgasket issue.
Click to expand...

This

Seriously take your water pump out and check to see if you can spin the impeller on the shaft. I have seen that before where there is just enough friction for the impeller to work at low speeds but under constant higher rpm cause the engine to overheat because it simply is slipping on the impeller shaft reducing flow through the engine. I know it sounds far fetched but I have seen it before.
 
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