I have an issue that I have noticed this winter but happens all the time. I will warm the truck up but won’t get hot air right away I’ll be driving and it will go from luke warm and like a switch was turned on bam it will be hot. No odd sounds when this happens. Not sure whats Going on.

 

How is your coolant level?

 

It’s fine just had it flushed and fill a couple of months ago. Was pressure tested

 

Is that when the problem manifested?