No heat when driving around town, But plenty of heat when running down the highway.
Air in system?

 

When this happened to me I was low on coolant. Have you checked the reservoir?

 

Yup, 3/4 of a gallon low on coolant.
When I remote start it 10 minutes before work, there is a lot of white smoke and a puddle of water on the ground at the exhaust pipe. Head gasket going?

It was also over a quart low on oil...

 

With the white smoke it does sound like a head gasket leak.

That being said - you just need to watch it closely and be sure. Could be one of the plastic fittings on the heater hoses, really bad water pump leak (that would really need to be slinging some coolant to the belts to get enough on the exhaust to smoke though). I'd certainly be finding the source of the leak asap.

 

White smoke and puddle coming from exhaust pipe, not in the engine compartment.

 

Oh...... that's not a good sign but on early cool mornings it's not necessarily a problem either as condensation does develop in engines which can produce some steam and condensation but that should subside as the engine warms up. But if you can detect any sort of coolant smell in the exhaust, yeah that is definitely a problem. If its bad enough your oil will get a milky sort of look to it as well. If not fixed quickly that will destroy the engine (the bearings, cylinder walls, etc will get trashed).

On a side note, that is a mistake many make on infrequently used vehicles (and other things like forklifts, etc) is they crank them up once a month to keep things in good order but they often do not let it run long enough. Always best to let an engine warm fully up as that makes sure any latent condensation is boiled away. I've seen a lot of things that do not get run often with rust all in the engine from that.

 

Smoke goes away after warm up, but coolant is still disappearing. We've only had the truck for a month, so not sure how low the coolant was when we bought it.

 

You probably need a new radiator. You'll definitely want to figure out where the coolant leak is ASAP. And install an external transmission cooler while you're at it

 

Coolant level drops to about an inch above the lower hose in the reservoir.
Just wondering why it doesn't leak all the way down, and comletly drain the reservoir?
Unless a heater hose is cracked, above that level in the tank.

 

Clear fluid coming from here. Behind passenger front tire