Heater blowing cold air

Good morning,

The old heater core may have been clogged with debris. When you replaced it, the core worked for a while until the debris clogged the new core.

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars

I would remove the two hoses to the heater core and flush the core with a garden hose. Flush it back and forth several times until you get a nice even flow in both directions.

Then hook it back up, top off the coolant, and test.

Roy

Is necessary to change radiator or not? also, I wanted to ask you if flap motor is not working good.

I would flush the system of all old coolants and replace it. At this point, no, I don't see any reason to replace the radiator.

As far as the blend door, when you command heat and cold, can you hear the door move in the dash? If you have a cable, is it hooked on both ends?

Roy

At driver side blows hot at other side blow cold, flap motor is working but I don't know if it is closing good blend door.

This sounds like the blend door actuator itself. Try feeling it move and make sure the sweep is correct.

https://www.2carpros.com/articles/replace-blend-door-motor

I would still blow out the heater core.

Can I have the complete VIN number for your car?

Roy

Roy, can you send me your what's up or Facebook?

We need to communicate on this site.

Roy

At summer my car blows more hot when is winter starts to blow cold.

Okay, you have to start somewhere, and I would start by flushing the core as I suggested.

Roy

Is there a golf tube MK6 to empty the antifreeze?

There should be a drain plug at the bottom of the radiator for removing the coolant.

If there is not, then remove the lower radiator hose to remove the coolant.

Roy