heater goes on/off

[Geronimoo]

S'mee again!

The heater blows warm air when the engine has relatively high rpm, but as soon as I idle it takes about 10 seconds and the air gets cold again. Throttle up and it gets warm in the same amount of time.

With these symptoms, what could be the problem?

[a.graham52]

Air in the coolant, low coolant, or clogged heater hose

[guiguilandry]

air in the coolant can be a sign of LIMG or headgasket failing too...

[MMGT1]

I was going to say head gasket myself man

[RalphP]

Can also be a partially plugged heater core.

Time for a flush (preferably a backflush of the core!), and after that, be VERY certain to burp the cooling system properly.

And if that doesn't fix it, it's time to see why the darn thing is getting that air bubble in it.

RwP

[Geronimoo]

There's enough coolant in the tank now. If I rev the engine, the coolant pump goes faster and increases the flow or is it just a static rpm?

[AXLE]

It goes faster as rpm increases

[Balero]

I have the same problem. Was this ever resolved?

[Papa Rad17]

Search for threads about LIMG Lower Intake Manifold Gasket failure. very common, tons of info already here. You will find your answers there.

[Redog]

Could be a lot of things.

The good thing is that this is a easy probelm to figure out because every car does this at some point.

To me it sounds like a leak in the cooling system somewhere. Puking coolant from the overflow after a WOT is a sign of a head gasket letting combusion gasses into the coolant jackets.

Cheapest thing to check first, thermostat :awesome: