engine temp cool?

[Chris Green]

I am going to change the stat, and flush the coolant on the weekend.

Also, my heater doesn't work (I get a bit of hot air at the start of the journey, and after that, its all a bit random!). Could this be linked to the fact that my car is running quite hot?

In traffic yesterday, the temp gauge moved up to about 5mm away from the top. I was very worried at that point.

[rubjonny]

It depends why your heater isn't working.  If its clogged up, then chances are the coolant channels in your block are too!  When I took the head off mine to do the exhaust I found that nearly all the channels thru the head gasket were clogged up with crap, once they were clear my engine ran a touch under halfway rather than a touch over halfway.

I'd start by removing the bypass valves and make sure you do a thourough flush & reverse flush on the block, rad and matrix whilst you have the thermostat out.

The matrix does help to cool the engine a bit, its just a small radiator after all