I have an 01 with an automatic and was wondering if my thermostat might need replacing. The truck has 30,000 miles on it and the t-stat has never been replaced. Since winter came I notice that I have to drive quite a distance before the engine is up to temp. Tonight I started with a cold engine, air temp was about 16 F. I had to drive 12 miles at 50mph before the temp hand was up. When I plug the truck in I usually have the block heater on a timer for about 2 hours, you notice the engine starts alot better but no heat felt from the vents inside. If the t-stat was staying open a little the block heater wouldn't do quite as good a job ?
I know a diesel is slower warming up than a gasser but I also drive a Power Stroke and it heats to normal in about 4 miles at the same temps..

 

Do you have a winter front on there to help with warmup? I see that you're posting from cold, cold Canada

 

No winter front, I guess when you grow up here and you get use to the weather you just don't think of those things. I guess it would help though.

 

From my experience, that warm up time sounds about right when not loaded. Be careful about using a winter front (unless it's -30 or worse) if you're loading the engine heavily, as it will prevent the intercooler from functioning properly.