I only get heat in the cab when the revs are high
The engine takes a long time to heat up

I have put in a winter thermostat and did a heater core flush

 

What's a winter thermostat? Stock is 195 degree.

You show all the signs of being low on coolant, and a failed thermostat.

 

New thermostat was put in and I am not low on coolant

 

new thermostats can fail. seen it happen. just be glad it didnt get stuck closed!

 

Does your engine get up to temp? How long does it take?

If everything else is as it should be, there is more than likely a blockage, or air bubble in the system. Heater core is notorious for trapping air..... (being as it's the highest point in the cooling system.......)

 

If my heater core is leaking when I put the heat to the floor fans, can I flush the heater core lines? Or do I HAVE to replace my whole heater core? ---Heat gets warm after truck has been warm, but then goes to luke warm air sometimes.

 

Unclamp your two heater lines and spray water through them first. See if that helps out any.


I did that and switched from my 180* tstat to a 195* for winter and it helped some. Still don't have HOT heat.

 

Which lines would I be running water through Both the left and right.?

 

If your heater core is leaking, you need to replace it.

 

It's not leaking anymore, only the short period of time when I got it back from the dealership (had a diagnosis for my motor) but noticing a bird chirping like sound in the dash. Alway been there just never though of anything until I read about "that" sound.