my 1998 mpv mazda van is overheating with a new water pump and thermostat

your radiator is clogged~

check with a less than 20 dollars thermo-spot gun~

It's a 1998 with how many miles? Sounds to me like more of a head gasket issue

Or intake gasket. You could remove the rad and it would not over heat in that short of time

Did you bleed air out system.? You might have air lock in your cooling system. Good Luck

We have the same issue. Did you find the problem? Was it bleeding out the air? I hope that's all it is for us :/