Topping off the coolant

[scottwkurth]

Non-MINI-specific-question:

A friend of mine asked me whether topping off the coolant (with antifreeze) will make the heater blow warmer air. As a (former) mechanical engineer (it has been a few years now ), I was embarassed to not know the answer right off the top of my head. My gut tells me no, but I'm not sure and feeling a little bit lazy about working it out in my head.

So, I turn to the experts. Any help?

[lotuseatsvipers]

I cannot dream of why that would occur??

..then again I don't pretend to know everything.

[scottwkurth]

The full story on this is that my friend's daughter claimed that they taught her in drivers' education that ensuring that the coolant level is topped off will make their heaters blow warmer air. My gut reaction to this was that as long as we are not talking about situations where there is no or not enough coolant (e.g. a real problem) then this should make no difference.

[HarryHBMCC]

When coolant is low you can get hotter air coming out but often the vapour locks/air pockets that form can end up in the heater core and then you'll get NO heat in the passenger cabin so the advice to keep it topped off is good for both the cooling system of the car's engine and the heating system for the people in it.

Harry