My Mazda MPV 1995 is overheating. I have changed the thermostat and fklushed the radiator. The water pump seems fine. Of note is the bottom hose going to the thrmostat is cold. Does this mean the water is not circulating?

Hi
The car will definitely not over heat because you haven't put any antifreeze in ,yes some antifreeze's also work as a summer coolant but you can rule the antifreeze out its definitely something else causing your overheating problem is your cooling fan working correctly ?
Hope this helps Nick

Check the radiator-it may have blockage. Take it off and turn upside down and flush from the bottom.
If the top hose gets hot, that means the thermostat is opening. The bottom hose should be at least warm, and quite warm if radiator flow is good.

!st check and make sure the water is flowing in the radiator, then check
the timeing, Mazda will run hot if the timeing is rong.

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.

Have a cooling system flush..your heater core may be clogged.

if you changed water pump did you plug the fan back in did you bleed the radiator to change that water pump its alot of work ive done about 6 of them in my life time its not easy to get to the water pump on that vehicle http://video.advanceautoparts.com/ its in the end of your radiator hose in a metal houseing remove the bolts on the end of the hose away from your engine when you replace that replace the gasket also that the thermostat houseing sits on fill radiator to proper level once done hope you didnt blow your head gasket good luck

It could be the radiator is bad. There is a plug located on the bottom of the radiator. Unscrew the plug and let the fluid drain, you should be able to see if there is rust or gunk in the water/antifreeze. Then use a garden hose and put it in the hole used to fill the radiator and let the water run.

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

You probably never cleaned the cooling system out.

If you have not get it done by pros.

It seems something is blocking the flow. If the water pump went bad you will know. Rarely ever heard a impeller breaks off like you think. The bearings and the seal break first.

Check and see also if the heater valve is working.

As for the over heating even new thermostats fail. Reverse flush is needed or the procan measure the pressure in the radiator cooling system and edetermine if there is a engine pressure problem. Tools and experience is the key in the game of diagnosis.







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