I have a 2000 mazda mpv es, it had been overheating. I have recently replace the fan, the water pump, the thermostat and the temperature sensor. The radiator is about two years old. After I replace the temperature sensor, it worked fine for a few weeks, but now the temperature gauge has started going up when I drive then it will go down when idled. There is coolant in the tank and It does not seem like the engine is overheating cause there is no noise or vapor or anything but I am afraid to drive it and I don't know what more to do since I have fixed almost the entire cooling system.

check thermostat and water pump

I've owned my 2000 MPV since new and in that time and 250K miles later I have replaced the radiator and water pump and overflow tank. I have never bleed the cooling system. I have encountered no cooling related problem. I live in south Florida.

check the water pump and the heater core

Replace the thermostat

Hello,

If you car is still overheating with new water pump and new hoses, there is still a few other things that can cause your over heating problem. Now, by you replacing water pump is good that you took care of one of the main things, however here is some other things to look at.

Number One, is your thermostat. Sometimes the thermostat gets worn out, and will not open and close properly, it is designed to open under a certain temp, but it could be stuck or warn out.

Number two, is check out your radiator, can put under pressure test, but best thing to do is a radiator flush, and see if flows proper. Sometimes the radiator core/coils get clogged.

Number Three. Check to see if your fans are coming on and proper speeds, normally as car gets to a certain temperature, they will kick into high speed.

Last thing, is make sure you have no head gasket leaks, as this could cause over heating, best way to check that, if its not obvious is, pressure test.


My opinion what I would first check, is the water thermostat and then radiator flush, if fan is working.

Thanks Mike.

there will be a sensor to activate the cooling fan possibly in the radiator. I would be looking at this

Check coolant level. if its ok than ride. If from expansion cap coming some flush or many many coolant aut check thermostat and check cooling fan system is sensor ok and relay.

not a lot of help on this one,sounds like you have some blockage somewhere,faulty thermostat.

possible head gasket do a preasure test on the coolant system to see if it loses any coolant or presure drops and check for leaks hope this helps