Heater Problem

[cripti0n]

So i know a new heater core is going to be a lot of work, so I am hoping that is not my problem. Here is a little description below of what some symptoms are...

When the car is warmed up and i turn on the heat it will blow warm (not hot) for a few seconds then goes cold. I can turn the blower off for a couple minutes and then back on, its warms for a few seconds and a few seconds later it is cold again.

What i have checked....

- No Coolant smell when it should be blowing heat
- No water in passenger floor
- Both inlet and outlet pipes to heater core are warm
- I can hear the flap motor and see an arm moving when i change from hot to cold.


I had the dealership flush the coolant the other week, however i don't know if they backflushed the heater core.


Can anyone tell me if i should suspect the heater core or something else?
Could the cabin temperature sensor be bad and cause this problem?

[cripti0n]

For anyone that has a heater problem... don't make the mistake i did.

First the car should be warm.

When checking the inlet and outlet line of the heater core, make sure the heat is on.

Before i checked with it off, and they were both warm.

With it on, the inlet was hot (uncomfortable to hold for a long time) and the outlet was only warm.

Had to flush the heater core 3 times, and now i have heat again.