Is this a radiator, water pump, heater core, or thermostat issue? https://www.youtube.com/watch?v=mTNJyjYdIDQ?

Question

I'm not getting any heat inside, and occationally my engine overheats. If I stop the engine and re-start, sometimes everything corrects itself and I can keep driving. because this is a phantom problem my mechanic friend can't diagnose it. Please help, I created a video of them problem here: https://www.youtube.com/watch?v=mTNJyjYdIDQ
2 hours ago - 4 days left to answer.
Additional Details
This is a 2002 Nissan Sentra XE 1.8L
1 hour ago

The radiator has 1 hot hose, and 1 cold hose. Same goes for the heater core, 1 hose is hot, the other is cold. This makes me think it's a water pump issue. I recently replaced the thermostat about 3 weeks ago when I first had this issue, but it could have been a defective one from the store too...
1 hour ago

The Awesome Michael S previously wrote:
You have a radiator cap so start with the engine cold and the radiator full. Leave the cap off and start the engine. In about 5-10 minutes the flow of coolant should come rushing passed the radiator opening. This will show you that the thermostat and the water pump are working. If the flow doesn't start rushing passed the opening and the engine starts overheating then you have a problem with either the thermostat or the water pump. That is simple.
You checked the heater hoses and you aren't getting coolant flow through the heater core. Look back along the heater hoses and see if there is a heater control valve that controls the coolant flow through the heater core. If not then you have a blockage in the heater core and you can probably flush it out with a garden hose into one of the heater hoses and letting the other hang.
You also have to check the radiator fan for proper operation because that can cause overheating.

Michael S: Thank you for your help! After removing the radiator cap the coolant starts to overflow out of the opening. Also, this car doesn't have any valves going to the heater core.

Answer 1

sounds to me like it could be 3 different things ! the thermostat is sticking closed part of the time, the radiator might need flushed and if your not getting any heat inside the car then the heater core might be clogged up !

Answer 2

Youtube Water Pump

Answer 3

is it loosing it in the time of the over circulate? what year make and type? theres alot of chevys thats you need to do intake artwork on. yet specific it must be haed gasket, yet in many situations overheats from that. not sufficient information to help

Answer 4

Great answers, just what I was searching for.