2002 heater problem

Lack of prestone

it could be you have an air lock in the cooling system
remove the rad cap from the rad, start the engine and let it run until the coolant drops (add to fill it back up) or until the coolant boils out of the rad spout.

maybe pull the heat sensor. -replace it OR clean it off, reinstall it.

sounds like the thermostat may not be opening.

There are other things to test before we have the engine spread all over the yard. Cooling fan operation. Yes the thermostat hot air in heater just means hot water. start with a cold engine then start and run at a high idle if heats quickly upper radiator hose hot lower cold good but reverse no flow. remove and test thermostat (not replace) put on stove boil water and watch it open once center piece is moving check with thermometer it should agree with stamp number on thermostat. if good check for slipping fan belt. check for air restrictions on radiator and water flow.

The dash gauges are notoriously inaccurate. But it is possible that the thermostat is stuck open. Does the upper radiator hose get hot after engine warmed up? Also feel both heater hoses-when engine is warm, both should be hot-indicating the coolant is circulating through the heater core. If heater hoses are hot, and you still have cold air, the temperature blend door on the heater case may not be operating.
Try a new thermostat and see if engine warms up faster and better.

no heat engine running hot sound like faulty thermostat which is sticking closed.if thermostat stuck closed no coolant can circulate through the engine block and radiator causing no heat condition and engine overheating.replace thermostat and radiator pressure or surge tank over jug cap see what happens.

It could most certainly be a bad or stuck thermostat, but on a 1997 model, your water pump may be gone (or not circulating enough coolant).
This is why its only heating up while in traffic - there is no airflow cooling the fins of your radiator from moving at speed.
I would check this out - WHILE ENGINE IS COLD - Start the engine and then remove the radiator cap - you should see coolant circulating from the movement of the water pump. Let it run 5-10 minutes to see if the thermostat will open - if it does open, your temp gauge should come down from the opening of the thermostat

need to check to see if radiator is circulation the water . hose good make sure their no soft an sucking shut especaily the bottom hose . you can get a temp gauge take radiator cap off ,let warm up til thermostat opens put gauge in radiator see what temp. is . (wife got meat or candy temp gauge this will work) last it could be heater core bad.

There could be many causes for this to happen. The thermostat could be sticking and only opening enough during higher engine rpm. The fan may not be coming on. The system could be clogged and not allowing much coolant to circulate until higher rpm. If this is something you want to tackle on your own I would suggest changing the Thermostat and thoroughly flushing the cooling system, then see how it acts and go from there.

Hi

Your engine thermostat is stuck open and this is what is causing the problem. You will need to have a new thermostat fitted - Usual cost is between $15 to $30. Maybe less depending on thermostat type.

How the thermostat works is it remains in a closed position within the engines coolant circulating system to allow the engine to heat and reach its optimum operating temperature. The thermostat then opens to allow the coolant to circulate freely. When the thermostat becomes faulty it fails to respond to the temperature of the coolant. What has happened it that it has opened and is stuck in an open position allowing the water to circulate too freely around the engine - you will see a brief rise in temperature when the engine is worked hard but as soon as you come to rest the temperature falls back again as the thermostat is not closing when it should.

Solution - replace thermostat and all will be well!

Hope this helps. Please remember to rate my answer. Many Thanks.