ShoddyHog

2009 LMG 5.3 - With clean reports from Blackstone, I'm now running 10,000 miles between changes. It doesn't use a drop in that 10,000 miles.

Freon? In a 2001 Tahoe? That'd be a hoot. OP, is your compressor clutch engaged when it is blowing hot air, or does the compressor kick off? If it stays on, check the clutch like the others suggested, but if it is kicking off, then you either have a low or high pressure. Gerry