Weird Heat Problem

[PeaveyBassist]

Tonight I drove out to get some food. Temperature is 30 degrees. The car was cold to start but once it warmed up I was getting good heat through the vents. I had to stop at a stop light and wait for a couple minutes and at idle I got VERY little heat. If revved up, it would start putting out good heat again, and then when back to idle, it would get colder again. Also, when turned back to cold the air got very cold, so it had little heat but it still felt cold to the touch. Could it be the thermostat stuck mostly closed? The waterpump was changed with the timing belt about 15k miles ago so I wouldnt think it would be the water pump. Also lately with the temps around 60 degrees at idle for a couple minutes the temp would start to climb PAST the halfway mark when before it would go to about 1/2 and then stay there. Any ideers?

Will

[RobertK]

Sounds like the water pump is not pushing enough water at idle to circulate through the heater core fast enough.

[PeaveyBassist]

The water pump is only 15k miles old though. It was changed last spring with the timing belt. I wouldnt think a water pump would go bad in less than 20k miles. Is it possible that its the thermostat? I dont believe the thermostat has been changed and the car has 167k miles on it. I was thinking about getting one from work (about $10) and changing it anyways just to make sure.

Will

[Dave]

t stat, or maybe air in the line? Tried bleeding it again?

[PeaveyBassist]

I need to do a coolant flush before it starts getting real cold. Then I can bleed it and what not. I havent really had a problem with the car overheating. It would always climb to 1/2 and stay there then go back down to about 1/4 when I drove and the fan on front of the engine cooled it down.

Will