I have a 2001 1500 2WD that is using coolant and I can't figure out where it's going. I have no wet carpet(heater core) , I get no puddle under truck when parked, oil looks fine, what else should I ckeck??

 

I would check for a cracked head or blown head gasket

 

Start the truck and let it get up to temp. Then open the god and take a look around, don't wear loose clothing and be careful around the fan.

Sometimes the thermostat gasket likes to fail and it will puddle right there on the intake, and then it will start to leak down hit the block and evaporate. I could even see steam.

If you still can't see anything try crawling under if and looking up.

Does it blow smoke or have poor power?

 

A leaking heater core won't necessarily leak on the carpet. The HVAC plenum houses both the heater core and the evaporator, so it could be exiting the plenum drain.

 

How much coolant are you using?
If it is not a large amount, it may be the water pump just starting to go.
Mine was using up a gallon in a week (350 miles)... there was a trickle that tracked down the front of the block and dripped off the oil pan lip onto the cross member.
It only leaked when hot (under pressure) and running, so there wasn't enough to puddle under the vehicle when stopped.
As it got worse, it would make it to the harmonic balancer and throw onto the inside of the fenders, but still not be enough to make an obvious puddle.
After running, look for a fluid track from the bottom of the water pump towards the crank... it is difficult to get a clear view of the area from under the hood, so crawl under the front bumper on the passenger side and look up towards the water pump.

 

Also with the engine off crawl up there with a bright flashlight next to the rad hose where the tstat is, silly bypass hose or gasket.