Run around won't blow hot....

[eltax91]

Hi all

My sister in law has a 51 plate corsa c with the wheezy little 1.0 engine up front.

Recently it's decided to stop blowing warm air. The blowers still work at full tilt and blast air out in plentiful supply, but only the cold air feeds work.

I've read a few forum posts, the carpets are not wet and the at gets up to temp and runs fine with no signs of HGF

So far, my brother has replaced the thermostat, removed the heater matrix and flushed it with a hose pipe. When the car is up to temperature the heater matrix inlet, outlet and find are red hot suggesting it's ok.

When you move the dial from cold to hot you can here the 'flaps' moving as if it's changing feed.

So, any ideas? Any experiences on the corsa in particular. Cheers for any help.

[Jazoli]

Vanes on the water pump have failed by the sounds of it, I had a similar problem with a Zafira, everthing was as your corsa, the pump would move enough water for everthing to feel hot but in reality the matrix wasn't able to get hot enough when pushing cold air over it.

Disconnect a heater hose, upwind of the water pump, point it to the floor and crank the engine over, if the water doesn't spurt out like a geyser and just trickles you have found your problem, possibly

Edited by Jazoli on Saturday 11th January 21:11

[eltax91]

Jazoli said:

Vanes on the water pump have failed by the sounds of it, I had a similar problem with a Zafira, everthing was as your corsa, the pump would move enough water for everthing to feel hot but in reality the matrix wasn't able to get hot enough when pushing cold air over it.

Disconnect a heater hose, upwind of the water pump, point it to the floor and crank the engine over, if the water doesn't spurt out like a geyser and just trickles you have found your problem, possibly

Edited by Jazoli on Saturday 11th January 21:11

That's interesting and certainly worth testing. What's the closest hose to the water pump? The inlet for the stat housing do?

[BFG TERRANO]

Wash the matrix out with a hose on low pressure. Or, is it air locked?

[Who me ?]

Air lock would be my first guess. Check pipes into /out of heater matrix. In hot, out cold - time to let some air/water out of heater matrix. It's worth keeping the heater working, as if stuck in a big traffic jam and engine starts getting too hot and traffic stop starting, the heater can save an overheat.