Tacoma Heater

[quote:d0043ac041="Zuess"]A question regarding my 2003 Tacoma, with the 3.4 liter V6. The truck has around 64,000 miles on it.

The heater blows cold air when the engine is idling. Plenty of hot air comes out when the engine is above an idle.

I drained cooling system last fall and replaced with Prestone/water. Have checked and radiator is full, although I didn't put any prestone in the overflow container last fall. I have since topped the overflow container up to the fill mark.

Temperature gauge is normal. Everything seems to be fine, just no hot air when engine speed drops to an idle.

Your advise is appreciated.[/quote:d0043ac041]

Find the thermostat and replace it-make sure follow the jiggle valve reinstallation

Thanks for the advice. To further my knowledge of the cooling system, what is going on with this system? Why does it work fine above idle rpms, but not at idle speeds. Is the thermostat stuck open or closed? And what is the jiggle valve and where is it located?

Thanks.

[quote:9ca8179f37="Zuess"]Thanks for the advice. To further my knowledge of the cooling system, what is going on with this system? Why does it work fine above idle rpms, but not at idle speeds. Is the thermostat stuck open or closed? And what is the jiggle valve and where is it located?

Thanks.[/quote:9ca8179f37]

The jiggle valve is on the thermostat-it has its own positioning with the housing, when you put it back-in other words its position.
Change it and see what happens.