I just changed my radiator and I put coolant in the car ndd ii tried to drive the car and itt still runs hot ohh and ii bought a new radiator cap and put it on why is itt still qettin hot and itts a 1997

disconnect both heater hoses at the motor, blow into either one to unclog it

Lack of prestone

The engine runs hotter the faster you drive. One of the things to check is the mixture of water and antifreeze. It has to be 50/50 or the engine over heats. The other thing is the air flow through the radiator OR the coolant flow through it. So it could be one of those issues. Open the radiator cap and inspect the inside with a light. Look for deposits on the internal capillary pipes. Check the fins on the outside of the radiator and make sure they are not mashed.

You have trapped air in the cooling system, purge the air out of the system. You can do this by raising the car front end as high as possible and filling the coolant recovery tank to the brim leave the cap off, then run engine until it reaches operating temperature, then shut it down and run cold water over the radiator core, the coolant tank will be sucked dry most likely as the air is purged and replaced by coolant.

Softly418 had this problem...........

This could result from a thermostat which is stuck closed (but you have a new one), or a failed coolant temp sensor not allowing the radiator fans to run when they should, but I think you have a blown head gasket. Overheating is a classic sign of combustion gases getting into the coolant. The pressure also forces it out of the overflow.

Warm up your engine a little, about half, and remove the radiator cap by putting a towel over it first. Then let the engine keep idling until hot while you look down the filler neck into the radiator......carefully.

If you see white bubbles like dry ice, that is a failed head gasket. If not, have a mechanic do a test for combustion gas in the coolant with a gadget like this

http://www.youtube.com/watch?v=1_SIwHMLmkM

plugged or bad catalytic converter, when my car surged while driving or at a stop it was a bad EGR Valve

bad thermostat and coolant maybe low. when a engine gets to hot at certain boiling point it evaporates

The water (coolant) in the expansion tank will rise and fall with the engine temperature. What the expansion tank does is collect and return coolant to and from the engine. When the engine warms up the coolant gets hot, builds up pressure and opens up the radiator cap. The coolant then goes into the expansion tank. Now when the engine cools down the pressure drops in the cooling system and the pressure drop (vacuum) pulls the coolant back into the engine via the radiator cap. The radiator cap allows the cooling system to build up pressure and by doing so increases the boiling point of the coolant, but when that pressure exceeds the caps rating the cap opens and the coolant goes to the expansion valve. The cap has another part to it that when the engine cools down and a partial vacuum is created in the cooling system a "valve" in the radiator cap opens and allows the coolant to be drawn back into the engine. I would look at your radiator cap to see if any gunk or build up is on it, and check the rubber gaskets for cracks. It's easiest just to replace the cap because they are inexpensive and easy to replace (2-10 dollars). The expansion tank should have two hoses on it. The one on the bottom comes from the radiator and the one on the top (possibly part of filler cap) runs down and is open to the ground. That way if it is overfilled or becomes overfilled it will slowly leak onto the ground. When and if you change your radiator cap, make sure the engine is cooled down, remove cap and start engine and turn heater to full blast, full heat. Leave the cap off and let it run until engine warmed up. This should burp out any air pockets that may have happened when coolant was changed. Also top off the coolant in the radiator while it is running. Hope this helps and good luck

I think you could be right about there being air trapped in the system.
Or the heater core(radiator) is plugged.
Either way you need a pressurized radiator coolant pump to put the coolant in without air being trapped.
Although,i have seen it done by jacking the vehicle up high enough that the radiator was now higher than the heater core level, and then the coolant was put in.
But this is dangerous to try.

you need maybe 1+1/2 gallon of distilled water;NOT TAP WATER and 1 gallon of Mazda Coolant; NOT 50/50 mix..

((WHEN THE ENGINE/COOLANT IS COOL>>VERY IMPORTANT!!!))

1.from the radiator, remove the drain plug, let it drain. for faster drain, also remove the resevoir cap.

2.when empty, put drain plug back on refill the resevior with the distilled water until full.

3.with the resevior cap off start engine with heat settings on Hi, until the coolant temp guage begin to rise or when thermostat opens. turn off engine.

4. repeat steps 1-3 until only clear water drains.

5.make sure drain plug is in, refill resevior with Mazda coolant til about half way (in case there's any expansion), do not put cap on yet, let the air bleed. start engine, let it run for 5 min.

6. accelerate in park/neutral to 2500RPM's (DO NOT drive yet) to help bleed the air keep an eye on coolant level because you will have to top it off.

7.check level as temp reaches normal; half point as usual. put resevior cap on drive around the block and check level again. make sure coolant is on the proper level; "F" or "MAX"...of course when the engine cools it will be below, but while the temp is normal it should be on the proper level.