I started the car up for the spring and found an interesting problem.

First off last year I thought the heater core was bad, good odor from the vents when the heat was on.

Now at a track event I tossed the accessory belt and it overheated a bit, spilled some coolant but never popped a head gasket. Filled it back up and drove it just fine for 2 more weeks before putting it away.

Today I start it up and let it come upto temp, see smoke waifting from the vents. Its on full hot but the water pump is running and I had the rad cap off to let it vent and make sure I had no air trapped.

Turn on the fan and it blows smoke....odd that there was no real smell to it. Turn it on cold and there is no smoke.

No overheating, no other problems....not sure where the smoke is coming from.

Any idea's, granted its an LS1 but this problem seems in the cabin.