Heating Suddenly Stopped, Getting Hot?

[Acknowledged74]

Hi

Typical for my luck the weather suddenly turns bad and my heater have stopped getting hot.

Anything obvious it might be, its a 08 Aygo ?

Thanks in advance.

Ash

[Acknowledged74]

Any ideas on this one, maybe its a common problem? Its My Mums car and we would rather be able to self diagnose, than have to pay for the privilage.

[daveyjp]

There are a number of things to check under bonnet and in cabin. The fact the Aygo doesn't have a temp gauge doesn't help in situations like this.

Is there adequate coolant in header tank? In cold weather a car can run with very little water in the system as air cooling will be adequate. No hot water means no cabin heat.

Faulty thermostat - easy enough to change.

Faulty heater matrix.

Cable dislodged on the heater control dial.

[Unklian]

1st, check coolant level. Water pump may have died.

http://www.toyotaownersclub.com/forums/index.php?showtopic=95418&hl=pump

If coolant level is OK, may be control cable.

To check......from memory......

Just to the left of your clutch pedal (RHD) is a white lever on the side of the heater matrix.

Check when you move your hot / cold control, that the lever is moved forwards / backwards.

If not, as a temporary measure to get some heat in the car, move it fully forwards / backwards,

(Can't remember which is which.)

Hope this helps.

Ian.

[Acknowledged74]

Heres a picture coolant level, there does seem to be a marker but its doesn't say what it is. Can anyone tell me if this needs topping up please?

[Unklian]

Yes, that is the marker.

With the engine cold, top up the coolant to that mark, then keep an eye on things.

You have only lost a little coolant. If your car is a few years old and you've never topped it up,

I wouldn't worry. Do check your water pump as I've described above, especially If you've never had one &

your Aygo is still using an early water pump. I notice you say its a 2008. My wife has a 2008 and that

had an "original" type pump on it. Yours probably has too.

Have you examined the hot / cold control on the heater matrix to see if things are

working properly in the control cable department?

Ian.

[Acknowledged74]

Ian

Thanks for the reply. Yes I checked the hot/cold control and its working fine.

I check in the engine i.e. the image from the link and theres no leakage there, not pink that I can see.

Is that coolant low enough to be the problem?

[Unklian]

Hi Ash.

Wouldn't have thought the coolant was low enough to cause a problem.

If the controls are working OK, my next thought would be your thermostat is stuck partly open.

Is the Aygo running OK? Has your mpg become worse?

Having no temperature gauge isn't helpful, the only quick test for an open thermostat is

to start the engine from cold, then under the bonnet, see if the radiator is warming up straight away.

If your thermostat is OK, the engine should warm up quickly, while the radiator stays cold.

At the correct temperature, the thermostat will open and the top of the radiator will become hot in

a sudden rush.

I beleve that you could connect a scangauge or similar diagnosic tool to see what your temperature is

and how fast the engine is coming up to normal temperature.

The weather is very cold at the moment and if you are running the heater flat out and not working the

engine hard, the heater won't blast out red hot air anyway.

Try a run on the motorway, the heater should get very hot.

Ian.