maybe a sensor problem, maybe thermostat?

[VCguy85]

Lately when I start my car, and let it warm up, it still pumps out cold air when i have the heat on. Then the thermostat guage goes all the way up to a little above 3/4 and then goes back down to 1/2 and THEN the heat works.

Related, I wanted to pass someone on an entrance ramp to the highway, so i gunned it revving about 5-6 k rpm and the thermo guage went all the way up to H and the light turned on and the TRAC light came on and it felt like i skipped down a gear or something... strange

Like I said, maybe it's a bad sensor (wouldn't suprise me) or the thermostat, or the fluid is low, if that's the case, what fluid is it? lol

[lonnie]

Idk but when my heat was blowing cold I found that I had to fill my coolant resevoir with fluid. (sp)

[01silveralero]

sounds like head gaskets or lower intake manifold gaskets for the temperature going up problem. the temperature should be in the middle. coolant temperature will either read or not read. there is no partial reading.