96 Crysler lhs over heating. I have replaced the radiator, water pump, timing is correct, all new hoses except heater core hoses, thermostat, cap to resevoir replaced, intake manifold gasket replaced, and all new belts. Also replaced a sensor on back of engine. No white smoke, no water coming from tail pipe and there is no milky oil. The water and antifreeze is bubbling in reservoir and coming out the over flow hose.

heater hoses run from the rear of the block to the water pump. One hose into the heater should be hotter than the other because heat is transferred in the heater in the car. . The cooling system draws water from the bottom of the radiator ( water pump inlet)which is always cooler than the top hose and dispenses it throughout the engine and heads including the heater core. It is then pushed past the thermostat with all the heat from the engine to the top of the radiator where it is cooled down by the air passing through the radiator . Check that the air vent for the cabin is set to recirculated cabin air and not fresh air from the outside as it will require recirculated air to increase in temperature to work properly

Hi Kim,

I can feel your frustration. It sounds like you've done all the logical stuff already. The "donut hole" in your process would seem to be not changing the water pump. The water pump as you might imagine, is responsible for circulating (pumping) the relatively cool water in the radiator into the running engine that contains the hot water. Hoses connect the two together. A thermostat is between the radiator and the engine. Once the water in the running engine gets to a certain temperature, the thermostat opens allowing the water pump to send cool water into the engine and hot water out to the radiator to be cooled. The heater core is usually on the passenger side firewall area.

It sounds like the water pump is the only thing left to change - if it isn't working - it can't circulate the water - and will result in overheating. Lastly, a clogged heater core shouldn't cause the engine to overheat - in fact, if the engine begins to overheat, you should turn the heat to HIGH fan and HIGH temperature to help remove some of the heat in the coolant.

Good luck!

What about the water pump if the water pump is working right there would be pressure somewhere.

You may have loosened or lost some material into the system while changing the pump and caused a blockage in the heater core. There could be a little coolant going through to warm up but not enough to continue supplying heat once the initial heat is drawn down.
Ideally a back flush through the heater core may take care of it. You should be able to find a kit to help with in an auto parts store.
Open the hood and look on the firewall of the car. There should be 2 rubber hoses going into the firewall and into the car. They will likely have spring clamps just like on the radiator hose. Remove both lines. Then get a hose and put it in one line and run the water until it comes out clear. Then do the same thing with the other side. Do this a couple of times. Then reconnect the 2 hoses ahd check the level of the radiator. Then start the car with the radiator cap off and wait a while for the thermostat to open and have the heater on so it will cycle through the whole system. Then top off as needed.

the cooling systems consists of a radiator, radiator cap, water pump, thermostat, hoses, heater core and sometime a heater control valve that open water lines to heater core. You may need a cooling system flush if water pump, radiator have been replaced. flush the system.change the thermostat and have the heater core checked too if you can get to it.
does the cooling fan kick on to cool the radiator..check that too.replace radiator cap and check cooling fan yourself...let me know if need anything else.
Thanks for using fixya and please vote.

If it is fogging your windows, you have a leaking heater core. Dash removal is required to fix it.

You made no mention of thermostat or radiator cap, both are common problems. The cap you can have tested at any good auto parts store, to see if it's holding adequate pressure.

Water pump may be worn and needs to be replaced. You can try flushing out the heater core it self buy disconnecting the two heater hose from the water pump and flushing water through it to get any restriction out. Once you flushed out the heater core, reattached the hose at the water pump and see if that helps. If not then your going to have to replace the water pump it self. Good luck

have you changed the coolent tank cap. Also have you checked to see if radiator fans are working

but is the water circulating ... if not its the water pump or thermostat