# Over Heating



## FatBoy4 (May 12, 2002)

Hey yall I need some help?

My car will over heat seems like every 3 months but I ususally get it before the dail goes above the H it just usually gets ruight undet the H

so I refill my coollant and the temp goes down.

I cant find any leaks does anyone have any suggestions on how to find out what is wrong or find out that is going on?


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## Teknokid (Jun 1, 2002)

Q: I'd like to get some tips on cooling. I know I should not speed, but I was doing some driving on the freeway and took the needle to 105. On the return trip, I was caught in traffic and my temperature needle went to the max. However once I get past that and keep the speed over 60 mph, the temp went back to normal level. What are my options for increasing air flow over the engine and under the hood? 

Sarah: Increasing airflow under the hood is for performance but it's your cooling system, the intricate maze of plumbing and parts in your engine and engine bay, that keeps it from overheating. Cars run best at about 200 degrees Farenheit. That is when they burn fuel most efficiently, emit less pollution, and the oil viscosity is lower (thinner) allowing better lubrication of the engine parts and less wear and tear. The cooling system must transfer heat generated by gas guzzling engines into the air. A 50/50 mix of water and antifreeze (coolant) is used because it has a very low freezing point, high boiling point, and can retain a lot of heat. The process starts with your water pump. Coolant flows into the water pump's center where centrifugal forces in the spinning pump fling the coolant into the engine block. It flows through the engine block and cylinder head through many channels that target the hottest parts of the engine where the coolant is most needed. Coolant leaves the engine through a thermostat. The thermostat stays shut when the engine is cold, forcing the coolant to recirculate through the engine so the engine will warm up quickly to its optimal operating temperature. When the coolant reaches about 180 degrees, the thermostat begins to open and coolant starts flowing into the radiator. The thermostat is fully open around 200 degrees, allowing the coolant to flow through the radiator and cool down, keeping the engine from overheating. The coolant travels through many thin, parallel tubes in the radiator where the heat can be absorbed into the air. The tubes contain turbulator fins which generate turbulence in the coolant flow, so the coolant mixes constantly and cools more efficiently. Cooling fans turn on when the coolant gets too hot to speed up the heat transfer. 

The last part of the cooling system is the radiator cap. As the coolant heats up, it expands and builds pressure. A pressure release valve on the radiator cap opens when the pressure hits about 15 psi, allowing the coolant to flow into the overflow tank. Transversely, coolant is drawn back into the radiator when it cools back down. A faulty cooling system is a quick way to blow a head gasket. Overheating is usually a sign of a problem with your cooling system: the cooling fans aren't turning on (fan relay, fuse, or ground probably); the thermostat, water pump (and water pump belt), and pressure cap aren't working properly; the radiator is blocked or restricted; or you're running low on coolant. If the engine seems to consume coolant, you may have a bad head gasket or broken engine block- check for water in the oil, the engine misfiring when it's started after a 15 minute to 3 hour break, or steam from the tailpipe. If you still have overheating problem, get an aftermarket radiator such as one made by Koyo. You can also improve heat transfer with an additive such as Red Line WaterWetter. 

http://www.nissanperformancemag.com/current/ask_sarah/


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## FatBoy4 (May 12, 2002)

This dont help me


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## 97PocketRocket (Jul 31, 2002)

heh, why not? that's actually a very clear article regarding typical problems causing engines to overheat. The first thing I'd do would be to replace the thermostat though, it's fairly common to cause overheating issues, reletively easy to replace and usually VERY cheap to get the part for. The fact that it overheats as rare as you stated makes it nearly impossible though to pin-point any particular problem. So the only thing you can do is probably rule out a cracked block and work on one part at a time starting on the thermostat and see if the problem eventually goes away completely.


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## jer28 (Jan 20, 2003)

Fatboy, I'm not trying to bust on ya but here goes. The info given to you was very good. If you don't have the motivation/skill to read the article, and understand it then why don't you just bring your dam car to a garage? You wanted advice from us out here and you got it. 

My 2 cents would be a leaky head gasket that has not quite blown. That might be why it is only every 3 months or so.


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## IanH (Feb 11, 2003)

jer28 has a very good input here. Thats my opion on the problem too ! 
Had this type of issue before, not with a Nisan though.

suggest you watch the coolent level and see if it goes down gradually or only when driven hard.

Let us know.

Ian.


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## FatBoy4 (May 12, 2002)

jer28 where I am sorry I really did not see how it helped me but I finally did figure outt hwta the problem is and I am going to try tog et it fixed saturytda


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## FatBoy4 (May 12, 2002)

Well it was my water pump that was leaking and fixed it on saturday so far no leaks 

but it does make a squicking noise any ideas?


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## jer28 (Jan 20, 2003)

Chances are it is probaly your belt. Check your belt tension, it could also be that your belt is glazed. I hear that squeaky belts are somewhat common for this car. My belts will squeal a little when it is really cold out but then they usually quiet up. In any event make sure that the belts look okay and are tensioned properly.


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## FatBoy4 (May 12, 2002)

Well see I dont know if he tightened it properly or not all he did was seem to tighten the bolt and push on the belt to see how loose it is and he said this was ok?


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## himilefrontier (Jan 21, 2003)

One thing I've had happen on a few older cars I've had is the seal on the radiator cap goes bad and starts leaking.When this happens,the water will leak out,but boil off the radiator before hitting the ground.Therefore you don't see anything on the ground,but loose water nonetheless.Change your radiator cap every few years to prevent this.


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