Please Help, Car Can't Decide If It's Hot Or Cold

[sega2k6]

Hi,

got a P reg corolla si, driving about in it the other day noticed that the heaters were blowing cold even though the switch was set to hot and the temp needle was up. Not a problem i thought, let it cool, topped up the radiator and left the cap off for a bit while the engine ran to let out any air.

The heater now runs hot when i'm revving the engine or driving along the road but as soon as i stop and leave it to tickover the blown air goes freezing cold.

First question is will the car be alright to drive like this or should I leave it alone?

Secondly, what could it be and will it be expensive/difficult to put right?

Any help you could offer would be much appreciated, also it has the 1.6 4afe engine, if that means anything to you?

Thanks in advance

Sega2k6

[cabcurtains]

I am not sure if this will help but here goes, i had these symptons in the past and it was the heater matrix, which is horrible and expensive job. The car was fine to use it just had no heating!

If non of this helps then ignore it :)

[chris up north]

Hi,

got a P reg corolla si, driving about in it the other day noticed that the heaters were blowing cold even though the switch was set to hot and the temp needle was up. Not a problem i thought, let it cool, topped up the radiator and left the cap off for a bit while the engine ran to let out any air.

The heater now runs hot when i'm revving the engine or driving along the road but as soon as i stop and leave it to tickover the blown air goes freezing cold.

First question is will the car be alright to drive like this or should I leave it alone?

Secondly, what could it be and will it be expensive/difficult to put right?

Any help you could offer would be much appreciated, also it has the 1.6 4afe engine, if that means anything to you?

Thanks in advance

Sega2k6

Hi there,

sounds very much as if your thermostat has jammed which is not unusual and a pretty cheap fix I don't know your engine but most (stats ) are under a small bell housing with a hose coming from it if so a reasonably easy self fix but make sure you get the little gasket that should come with it