Heater Matrix Vauxhall Corsa 1.2i 16v 1999

[sharona100]

Hi, had problems with heater not working, had new thermostat then had new heater matrix. Everything fine for a few weeks but now heater gets colder as temp guage nears 100. Any ideas?

[Seafarer1966]

Could be an airlock in your water system. Take the top off the expansion tank (thats where you put the water) and run the engine for a bit whilst its warmed up. Your car is light enough for a well built bloke to give your car a good shake on its suspension which works surprisingly well in many cases. This may dislodge any air bubbles in the system. Make sure you don't overfill expansion tank. Look at the min and max level indicators.

Could also be a dashboard problem. Hot air not getting through the vents from the heater matrix due to snapped or jammed levers. So when you turn the control to 'hot' it doesn't make any difference. The matrix always becomes hot when the engine warms up. Your heater controls simply allow the warmed air through your dashboard by raising or lowering flaps when you adjust the heater control.

Getting to the matrix on a Corsa is relatively easy. Just needs removal of black plastic lower panel to the left of the clutch pedal and you can touch the matrix to see if it gets hot when the engine warms up. You can also access the inlet and outlet matrix pipes in the engine compartment. These are at the back of the engine and quite low down. Touch them to see if they get hot. Can be difficult to get to. I changed the matrix on a 2000 reg. Corsa 1.7 diesel at Christmas and got my 11 year old son to undo and refasten the matrix hoses for me (his hands are a lot smaller!). He did a great job and earned himself some extra pocket money.

If matrix is hot I'd say your problem was the dashboard control thing above. If matrix is still cold even when engine warms up you have an airlock or more seriously a blockage in the water system.

[MRCoops]

Sharona
Just an idea !, have the same car and its done 70k miles. It needed a new head gasket , have you checked the oil for the dreaded "mayo" it was losing water before the gasket went, and the heater would blow cold. Hope this isn't the case good luck