Radiator pin-hole leaks -

If T-stat doesn't work/open it won't allow coolant to pump to heater core properly.

 

@na8rboy You are correct in that statement. I was referring to his situation. He said, “At the house opened up while engine running didn't spy anything fantastic - temp dropped to normal range pretty quick.” If his thermostat was stuck closed, the temps would stay high. Maybe he misspoke, or I misunderstand something.

 

Regardless, it's easy to gain access to the thermostat once the radiator is pulled anyways. Probably wouldn't hurt to replace the thermostat when replacing the radiator that's leaking. And definitely flush the system and heater core.

 

Unless he's has an air locked in system it would drop opening rad cap. We are both on right track here. Without being right there, it's a crap shoot diagnosing...lol

 

I probably misspoke - I am not by any stretch of the imagination a car-engine-dude. Give me a SQL Server and/or a spreadsheet full of numbers and I'll
whip that sh*t around like nobody's business - cars... tools... ummmm no.

 

You have air in your heater, common when you run low on coolant.

Just replace the radiator and call it a day.

Better to spend a few dollars on a proper repair than damaging the car by running low on coolant and overheating. Replacing the car will be a lot more expensive than the radiator.
You probably have a friend who could replace it for food & a couple of beers.

Good luck.