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hey guys i have a nissan sentra b14 am have overheating problems i have now change the radiator a few hoses and also bleed the air out the system fans work n heat works and ac!!! im at a complete loss at what to do next we have even replaced the valve cover gasket and spark plug rings also plugs and wires and have taking out the thermostat help me please and tht engine i have in is a GA14 fuel injection HELP PPPPLLLLLLLLLZZZZZZZZZZ
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when you replaced the hoses and radiator and such did there look like there was a lot of corrosion in the system? if so then your water pump “fins” could be corroded away and not pumping the coolant like it should. Generally there will be some coolant coming out of the “weep hole” on the water pump if this is the case but not all the time.
If you can get your hands on a coolant pressure tester it would help a lot. Hook it up and run your engine to see if it’s building up to 15-16 psi. Also pressurize your system with the engine off and see if your system is holding pressure properly.
Visit the nearest big chain auto store, and get a pressure tester for the cooling system. Make certain it comes with the proper adapters for your car.
First test, the radiator cap. Make certain it is holding 16 psi (or what ever the label on it says) of pressure. If it releases before 16, then that is very likely the cause of your overheating.
Test the cooling system, and be certain that it will hold 16 psi. If the pressure bleeds down, find your leak.
If that checks out, release the pressure, then, with the tester still attached to your radiator, start the engine, and watch the pressure. It should slowly build up to around the 16 PSI range. If the pressure QUICKLY jumps up, and goes well over that 16 PSI, then I would suspect perhaps a leak in the head gasket.
If I understood you correct, you have t-sta removed? And fans start? And car still overheats?
I am yet to see a car that will overheat with t-stat removed and fans blowing, as it’s basically free coolant flow and cold air supply.
Unless you have 2 things happening:
1. blown head gasket, resulting in hot exhaust getting into coolant and overheat
2. physical obstruction somewhere in the system, which the simplest one is a collapsed hose. Sometimes they have inner lining peal off and block coolant flow, or deter it enough to act as closed t-stat.
Or, you have air lock, but you claim to have bled the system.
I’d actually start with checking for exhaust leak into coolant.
If that checks out, locate both upper and lower radiator hose and feel them by hand at operating temp. If they are same by touch, you have unobstructed flow. If one is cooler – well, read #2.You should not run an engine without a thermostat. As for bleeding the system, did you follow the procedure in this video?
It’s very important you follow that procedure to be successful in getting the air out.
Additional information on how to diagnose and repair overheat issues can be found here.
http://www.ericthecarguy.com/faq/what-to-do-when-your-engine-overheats
Keep us posted on your progress.
Hi Eric.
His car is 95-99 model, he might as well have bleeder on t-stat housing.
But none of our modern cars in garage has them. Nor expansion canisters in the old fashion, nor radiator caps. They are all sealed systems with high pressure reservoirs instead of air open expansion canisters.
Even my wife’s 99 RX300 does not have bleeder.
But then they all have those reservoirs very high level up above the radiator and hoses, and entire system simply burps itself into that reservoir. Just did 08 Mazdadspeed. Was easiest “bleed” ever. Had to do nothing, fill her up, run, drive, come back, add a little bit to reservoir, boom, done.
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