still have coolant smell

I took my 2006 tdi Jetta in to the Dealership the other day for a bad thermostat, only 14,000 miles, they found it to be stuck in the open position so they relaced it. I told them i was also smelling coolant. I could not find a coolant leak anywhere, But while they had it they were going to do a pressure test that came back fine. No Leaks. Have been driving it now for about 2 days and can still smell coolant. Anyone with ideas on this?
Thanks

Heater core

I know it seems to be to early for the heater core to go, but that is what it sounds like to me. Are you getting a strong smell. When you hit the recirculate button do you still smell it? If so it is most likly that. If you have it on fresh air/outside air, then I would say its a leak outside. Make sure your cap on the filler tank is tight.
Rob

More than likely coolant got spilled in the engine compartment when they changedd the thermostat and it will take a while to burn off. Just keep an eye on the the level to make sure, but I bet you've got nothing to worry about. If the heater core were bad you'd have issues like the windshield fogging over, or a wet carpet.

Thanks for the info