# 2000 Altima Overheating



## trebor8820 (Jun 27, 2010)

Hello,

I have a 2000 Nissan Altima with 226k miles.

I am at a loss attempting to diagnose and repair my overheating problem. After a mile or two of driving, my temperature gauge starts slowly rising. It never makes it to the *H*, but I have seen it reach the line just before the *H*. Usually, I can turn the heater on (which blows very hot) and it will cool back down, but sometimes (depending on the heat of the day and my driving speed) it will stay slightly above normal operating range.

*Parts that I have changed:*
Radiator
Cooling Fans
Water pump
Thermostat (170º, replaced 3 times)
Coolant Temperature Sensor (both of them)
Lower and Upper Radiator Hoses

*Additionally...*
I have made several attempts to bleed the cooling system. These attempts have included utilizing the bleeder bolt located between the exhaust manifold and the water pump, running the car for periods of 30-45 minutes with the radiator cap removed and the front end of the car raised, and even filling the engine manually with a water hose (for diagnostic purposes).

I have tried running with and without the thermostat to eliminate that as a point of blockage, and I have also ruled out any other blockages in the engine/radiator by forcing water through every possible receptacle (water hose) to ensure that it comes out of the other ports accordingly. This has been done independently with the radiator, as well.

I have had the car checked out by a professional mechanic, also. He confirmed that the head gasket is not blown or otherwise damaged; which I figured as much as well, considering that the car was not displaying any symptoms of such. His suggestion was to have the radiator and/or the water pump checked/replaced. I removed and examined both today and found no defects. I have also confirmed that my belt is routed correctly. I tried running a flush through my engine, also to no avail.

As long as I don't run the A/C, the car will not overheat at idle, but it will overheat on the road regardless of whether or not I run the A/C.

I am running with 50/50 antifreeze. 

Any ideas appreciated,
Thanks!


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## altimanum1 (Jun 19, 2009)

If you replaced what u mentioned above.... and checked what you checked.... i will say its the head gasket do to so many miles. 

I had a similar problem but after replacing the thermostad the problem was solve. If it was the water pump it would make a certain kind of noise or it will leak antifreeze. 

When you check the antifreeze level... is it ever low? do you need to refill it?
Last thing i can think of is heater core but i doubt it.


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## bmxking192 (May 18, 2010)

*overheating*

i had similar problems with my altima turns out the blower fan fuses were all burnt out, and the blower fan wasnt turning on, replaced them and never had a problem again


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## Asleep (Jan 19, 2003)

is it actually _running_ hot or just indicating hot?
is it boiling over or any symptoms of actual overheating?
did you replace the radiator cap?
thermostat correct position?
heres a trick you can try thats free - drill a 1/8th" hole at the 12 o'clock position of the t-stat and reinstall it. if there is air in the system, the hole will let it pass thru instead of holding it.
did you reinstall the water pump or replace it?
what were the compression numbers?
one last thing - cylinder leakdown test.


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## trebor8820 (Jun 27, 2010)

Ah, actually this issue was resolved.. somehow in all of this the radiator managed to plug up; put a new one in (again) and it's doing great now!


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## Asleep (Jan 19, 2003)

sweet. good to hear!


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