Matiz - Heaters warm but not hot

[Deleted User]

Blowers working fine. But air coming out is warm but not hot.
Checked coolant level - fine.

Engine temp seems fine (if a little low).

Any ideas?

Norman_Castle

Possible thermostat stuck open. Is the temperature ok in town then drops when you travel at speed. Is there a milky white deposit on the underside of the fillercap.

TrickyWicky

Also your system might of developed an air lock so you might just want to try bleeding the cooling system just in case.

Remember also that in these freezing temperatures, car engines don't get as hot as easily as normal so it might not be producing as much heat as you would normally expect. I know mine is struggling to get over 1/4 of the temperature gauge and it normally sits at 1/3.

Iand1

Also, some early Matiz's had water pump failures, where the fins would rot away, giving the water a nice brownish colour.
Have had cases of Heater Matrix blockages on this model as well.

[Deleted User]

Norman_Castle wrote: »

Possible thermostat stuck open. Is the temperature ok in town then drops when you travel at speed. Is there a milky white deposit on the underside of the fillercap.

Water doesnt look that clean to be honest. Yeh, temp does seem to drop at speed.

Thermostat?

Norman_Castle

If the radiator top hose is warm after a short run with little heat avaliable from the heater then I would suspect the thermostat is stuck open. Normally cheap and easy to do. If your car is overcooling it can, in time, cause engine wear. Engines need to get hot for the oil to work properly.

boyse7en

it's probably just the cold weather. My Alfa usually sits at 85deg on the gauge. On a recent motorway run (at 70-and-a-bit mph) at didn't budge above 65 until we had to stop in traffic.

[Deleted User]

Yeh. But its not THAT cold at the moment and it is a bit of a nightmare to drive. Gotta wear a coat at moment.

jimmym105

boyse7en wrote: »

it's probably just the cold weather. My Alfa usually sits at 85deg on the gauge. On a recent motorway run (at 70-and-a-bit mph) at didn't budge above 65 until we had to stop in traffic.

That sounds like your thermostat is stuck open.....

forgotmyname

Ever been serviced? When did you last get the antifreeze checked?

mikey72

I've justed fixed that on mine. (not a Matiz though)

I did the thermostat, as the gauge was low, unless in traffic, I flushed it all through, refilled it.
Exactly the same.

Still luke warm air.

Eventually I traced it to the air flap on the heater itself. There's no water valve, the matrix is always hot, but the air is diverted instead. It wasn't shutting properly, so was always mixing cold air in.
I adjusted the cable, (not easy), and there is now a satisfying "clunk" when I put it in the hot position, and lovely warm toes.