My 1996 nissan maxima is overheating. Fans come on, new radiator, new thermostat. Heater now working, 1 hose on heater core not getting hot. Top radiator hose is bulging and water come out the radiato

SOURCE: 2000 maxima overheating

You have a new radiator and thermostat, so your coolant was flushed. Was the radiator "burped" afterward to get rid of air bubbles? If not, that needs to be done first - it would explain virtually every symptom you're seeing.

Jack up the car so that the radiator cap is elevated. With the coolant topped off, start the car and let it run until it's about 3/4 of the way to overheating. Then shut it down and go have a beer. When it cools off enough to safely open the radiator cap, do so, and any air trapped in the system will bleed out.

What you're doing is circulating the coolant and the air bubbles inside. The bubbles get lodged behind the thermostat and stay there, keeping it from opening (this causes the car to heat up). When you later pop the cap off the radiator, the pressure is vented from the system, the thermostat opens, and the bubbles pass through. They'll work their way to the radiator (since you've got it elevated) and pop out the open cap opening.

Your coolant level will likely drop somewhat after doing this, as the air bubbles will be gone and the space they took up in the system is now available. You may need to add a little more coolant, so top if off (with the car back on the ground) and recap the radiator, fill the overflow to the marked point on the tank, and you're good to go.

Try this if you haven't already, and post back up with your results. If it doesn't solve the problems, we'll take it further.

Phil Lovisek

• 726 Answers
• Posted on Aug 21, 2008

SOURCE: 2000 Maxima Overheating - STILL

You can't determine if your pump is bad. You just have to take it out and look at it. Its internal insisde the timing cover right by the timing chain. Those pumps are pretty bulletproof, because they are internal, but you never know. I have replaced 1 so far in my 12+ years with Nissan and that was a 1998 Maxima qwith over 200 000 miles. Unless you have a coolant leak or somekind of funny noise coming from the timing chain area, you really can't tell, if the pump is bad. good luck.

SOURCE: 1989 maxima no heat in vehicle

Put your hand on the heater hoses as close to the fire wall as possible find out if both hoses are hot.Do this when the vehicle is cold allow car to heat up with heater open and running.If both equaly hot then heater core at fault.If different check water supply to cold hose.

SOURCE: 2000 Nissan Altima temperature gauge and heater problem

sounds like you need to replace the thermostat.

SOURCE: 2004 NISSAN ALTIMA 2.5 NO CABIN HEAT..ENGINE AT OPERATING TEMP.

If the engine is not over heating than most lilely it isn't the thermostat or waterpump that is causing the problem. Check the heater hose coming out of the manifold and see if it is warm to hot. Next check the return line from the heater if it is still cold or moch cooler than the inlet, the most possible problem is the heater water control valve if this model has one or possible the core of the heater is plugg with slime cause by some antifreezes setting during the summer months while not being used. If this is the case than remove tihe two hoses and back flush the heater core with water pressure until it runs clear. I have had this problem before and this cured my problem. I also had to flush the engine and radatior also. Hope this help. .