# Overheating problems



## Hilmee (Dec 14, 2006)

My 1993 Nissan Altima SE is overheating. I replaced the thermostat and it did not solve it. I just took off the water pump but it looks fine but not sure how to tell if it is faulty. I will probably put a new one on anyways since I have it off. When it gets hot, the hose coming in to the top of the radiator to the left (when looking at the car) is very hot and the one on the right is still cold which led me to believe that the waterpump was not working. Does anyone else know what could be causing my problem?


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## mech361 (Jul 31, 2006)

Did you bleed the cooling system after replacing your t-stat? Air in the cooling system can make your car run hot as well.


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## Hilmee (Dec 14, 2006)

mech361, 

I have never performed a bleed of a cooling system before. I think you may be on to something. Do you have an references you could point me to that shows one how to do this. Is it fairly easy and if so is it something you could share in your reply? Thanks man!


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## KA24Tech (Feb 2, 2004)

There is an air bleed fitting on the thermostat housing.
While the engine is cool, open the air bleed and pour coolant in the radiator fill neck until the coolant comes out of the bleed hole. Close and retighten the fitting and then continue to refill the radiator until the full. Fill the reservior to the slightly above the max line. Ensure the radiator cap is tight and start the engine run it until warm and rev the engine two to three times for a few seconds and then shut it off and let it cool. Check the coolant level in the radiator and top it off as necessary.
Another possible cause of overheating could be a defective radiator cap. You might consider replacing the radiator cap if it appears defective. Better auto parts stores can check it to see if it holds pressure. 

Troy


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## Hilmee (Dec 14, 2006)

I found the bleed fitting, thanks KA24Tech! I also relized it is shown in the owners manual. Now, I feel my water pump is fine. No play in the bearing, the fins look fine..... it seems solid. How can one tell if the pump is bad? Although I can get a new one for about $55 should I just put the old one back in and minimize my expense or just put a new one in to be safe? Any advice would be much appreciated. The car has over 150k on it and we will selling it soon.


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## mech361 (Jul 31, 2006)

Since you have the pump off already, I believe I would go ahead and replace it. Better safe than sorry.


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## Hilmee (Dec 14, 2006)

Great, thanks mech361! I appreciate your input very much........ anyone else want to chime in?


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## KA24Tech (Feb 2, 2004)

To tell if a pump is going bad it will usually have coolant residue around the weep hole on the bottom. It will sometimes be noisy as well. 
Remember to check the radiator cap as well.

Troy


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