Hello everyone, this morning, as a lot of us I'm sure, got up with frost on the windshield. I was in no rush so I started her up and turned defrost on and fan on high and watched from the house as it cleared. After 10 minutes or so it was clear so I jumped in and noticed it wasn't hot in the cab as I was sure it would be. I looked at the temperature hand and it was only a little above C. I left and kept an eye on the gauge and it slowly came up to where it usually runs, then it was HOT in the cab. Being it took a while for the hand to get to normal running position, would this sound like the thermostat is stuck open?

 

Sounds like a partially clogged heater core, makes it take a while to warm up.

 

Are sure it's not just it's cold and it take a minute for the big cab to warm up? Cause if the window is defrosting it's obviously warm if not hot.

 

At first mine just started taking a while to warm up after defrosting, then it started taking forever to defrost, then it pissed antifreeze into my floor and out from under the truck.

 

Check to make sure you have enough antifreeze too...

 

So what was the total time it sat idle before the gauge moved?
Depends on the outside temperature also.

10 minutes might not have been enough time for the engine to warm up. Usually I don't get heat until I've driven a few miles. All my vehicles have been like this.

 

Yeah mines the same way it can idle for 15 min in 30% and the needle will just start to move! And also those gauges aren't that accurate.

 

Total time sitting idle was 15 minutes, then I started driving and it slowly crept up to where it usually stays. Total of both idle and driving 20 minutes. I'm going to add a few led lights tomorrow and I think I will get the garden hose and try to flush the heater coil and see what that does.