The heat does not work in my 1988 Toyota pickup. I've flushed the heater coil, bypassed the heater valve, and replaced the termostat. It appears that no coolant is making it to the heater coil, the feed hose and the return hose to the coil does not get hot. Could it be a water pump problem even though the truck does not run hot?

SOURCE: 1988 Pickup: 1988 toyota pickup wiper arm removal????...

Remove the cover located at windshield base with flatblade screw driver or other prying device. Remove retaining bolt, then while prying under wiper arm where it is attached to wiper motor shaft, wiggle wiper arm side to side and up & down. Don't be scared.

SOURCE: overheating

Follow the radiator hose to where it connects to the engine block. The thermostat will be in the housing to which the hose is connected.

SOURCE: 1995 Toyota Camry 4 cylinder runs hot

Hi,

Firstly, ensure you have the required 'mixture' of coolant/water (must have required coolant).

Second, I would recommend you re-test all the cooling system sensors again (make sure they're within specifications), in case a new one is faulty.

Third, ensure the new thermostat was of the correct temp setting (they all differ), so that it opens at the required time. Most cooling systems operate within 90 - 100degC.

Fourth, make sure the radiator (and associated hoses) aren't blocked.

If your temp gauge is reading higher than normal, but NOT in the danger zone...then this can be considered normal (especially if you've replaced with new components) and nothing to be concerned about.

However, if the temp gauge IS in the danger zone....then this suggests the coolant is not flowing through the cooling system properly.

If all above components test ok, then it's possible your water pump may not be pumping enough volume.

Cheers,

Testimonial: "I appreciate your help...Maybe I should just relace the water pump, that would be the last thing that I would need to replace."

SOURCE: coolant leak 1992 toyota pickup

do you know if they replaced the O ring rubber that connects the pipe under the intake Mark?
One of its trademarks is it only leaks after the vehicle sets overnight.

SOURCE: No heat/defrost 01 corolla

Sounds like you have air trapped in the heater core when you flushed the heater core. loosen the upper most heater core hose and run the engine untill coolant seeps out. Wait until the coolant has reached running temperature.