My car is overheating and i don't know why just trying to rule out as many options as possible.Things it is most likely not: blown gasket/cracked head, both replaced 2 years ago and no tell tale signs I will be doing a block test soon, thermostat replaced it and put the old one in hot water and it opened, hoses replaced with new one two years ago, no leaks pressure test a few days ago. Things yet to be ruled out The radiator being clogged or not allowing good airflow, water pump impeller failure.
Not nessesarily. because the pump could still be pumping , but leaking. When the thermostat gives out and the coolant gets low, then the heater will not blow cool air out. Anything that has a leak could be a cause for the coolant being low. Every time you remove the coolant from the system, bleed it by turning the bleed screw that is near the thermostat housing. be sure the car is hot enough before turning the screw slightly. You did not mention the year , model , and engine of the car. so I am assuming only. Radiator flush works well to clean out motors . Buy a can and follow directions. it may also be a coolant temperature sensor. This is a very important sensor because it affects the signals the Computer is getting. It may not run well. Have it scanned for a trouble code free at Autozone ot other store.
water pump is driven by the serpentine belt. if your belt is slipping then it wont run your water pump, so you could try getting another belt for like 20 bucks at an auto store. the heater is run electrically. well more importantly by a 'blower motor'. it could even be the blower motor resistor, they are connected to the blower motor, and usually have green tape on them. most likely it is going to be the water pump from what you have described
if you have no fan activity, it will get hot at low speeds and at a stop position.
If the water pump impeller fail your heater will not work properly because the coolant is not circulating .If coolant is low or restricted heater core will result more or less the same condition.However overheating can be cause by timing too.Blown head gasket can be verify with compression test.Water pump can leak while you are driving and may leave little to hard to detect trace of leak.It can pissing for a few seconds and stop for a while. Do not over look the pressure cap.It can cause overheating symptoms boiling over the recovery tank.Plug rad will definitely cause that.The cooling fan -if electric can be faulty. Some has a module or relay activate by a temperature sensor.Some has a temp.sensor sending signal to the COMPUTER and the computer turns the e-fan on or off.If any of those components is faulty.you can have overheating problems.check it out
