i noticed yesterday that when i depress the gas pedal the needle goes down to cold. when at a red light it goes back to the middle. what does this mean?

 

i have the same problem with my toyota seems like your thermostat is not clossing so when you drive in the highway you can see the thermostat needle drop and you start loosing warm air from the vent and start blowing cold air ....i would have a mechanic take look on the thermostat

 

thanks for the feed back. i was thinking the same thing

 

the only time I've seen this is when coasting down a long hill on the freeway, occasionally tapping the brakes only. Apparently so much cold air is being registered, it can't sense the engine heat. Either it's really cold where you are or sensor is messed up. But since it goes up at a light, it is sensing.

 

it's the thermostat was bad, and it was kept on an open position... so when ever your engine is running, the coolant will keep cycling, therefore it will keep taking out the heat from radiator. symptom will be hard to warm up the car, even tho it warmed up, ones the car gets going, temperature drops. no heat will be blown out even tho u turn your heat to 32C... lucky that it didnt caught on the close position because your engine will over heat!