I have 1999 mercury villager i replaced water pump thermostat still over heats was wondering if it could be the heater core cause i dont have heat in my van and the temp in my van gets up to the red

Hi Shawn,your thermostat may be stuck open,not letting your coolant heat up.check this first.here's a link on how to replace, GET 25 GIFT CARD FOR EVERY 100 SPENT ON ONLINE SHIP TO HOME ORDERS After removing,look at it,it should be closed,to see if it is working,boil water to 180 degrees with thermostat in pot,it should open at 180,remove from water and it should close,if it's doing this,then it's good,is your water pump working properly,no leaks.Here's another link to your heater core, GET 25 GIFT CARD FOR EVERY 100 SPENT ON ONLINE SHIP TO HOME ORDERS I am fixing to replace my heater core in my 85 Nissan 720 truck,did it 10 years ago,my heat still works,but my windows fog up super fast,which means it's leaking,can put my hand on the carpet by the heater core and feel coolant,it's a job.

Have it tested for combustion gases in the cooling system. You could have a blown head gasket from all the overheating.

Have your coolant system flushed then if the problem still exists then replace the heater core because it is clogged.

Two things.........either it's a bad blender motor,or more likely,plugged heater core..Remove heater hose from near thermostat and heater hose from water pump,and flush from water pump side heater hose back thru the heater core and out the thermostat side heater hose with a pistol grip type water nozzle. don-ohio

Check the water in the radiator, check the thermostat, check the valve going to the heater core that it is open.there is a vacuum line going to it, see that its drawing vacuum.

faulty water pump & or semi plugged up heater core can cause this problem

when you move the selector switch from cool to heat, do you hear the door move inside the heater box.? if not then check the blend door motor.

your heater core may be getting blocked up, or the thermostat may be stuck open at times. you have a few options here, option 1 and 2 cost about the same, option 1: have the thermostat replaced just so you know its working properly, a 97 will most likely not have a telltale way of knowing if the thermostat is bad or going bad. option 2. have the cooling system flushed at a shop. this will try to clear out and debris in the cooling system that may be blocking passages or the heater core. option 3 is the most expensive. have the heater core replaced, the heater core is what provides heat to the hvac system in the dash. a few other things to check would be vacuum lines/actuator/temperature door on your hvac system.

You have an air pocket in the cooling system. To bled it out you will have to park vehicle on an incline or jack up the front end untill the radiator cap is higher than the heater core. The remove radiator cap and run engine until warm then hold rpm to about 1200 rpm's and top off coolant level until you have no more bubbles.

are you shure that you dont have trapped air in the heater core? get a big funnel that will fit tightly in the radiator filler and fill with coolant and run the car to normal operating temp and watch for the level to drop or bubbles to evacuate into the funnel. on really stubborn air locks i have had to squeeze the hoses to pump water through the heater core.