Re: Thermostat or NTC?
Can't think why you should have a rubber smell from the heater itself. I've had the smell of antifreeze from the heater before but the two aren't particularly similar. In that case it was the heater matrix leaking. The smell could be coming from under the bonnet in which case it might be a belt smell - not terribly reassuring. Mines stinking of gear oil every time I stop at traffic lights since it's gearbox hernia. It's covered the underneath. If you were doing relatively short journeys I'd expect a duff thermostat to show up in fuel consumption but maybe not terribly obvious depending on your driving. When you do get the thing to show a decent temp on the gauge, make sure the fans do operate. The trouble with elelctric fans is that, again depending on your usage, they can spend the larger part of their life off. The switch contacts get a bit oxidised and WHHOSH! When you stop in a motorway jam or go on a different journey from usual taking you into traffic the things don't start just when their needed. I have a theory that quite a few engines have come to grief this way. Even where cars are fitted with gauges most of us forget they're there untill just after they're most needed!!
It's no consolation but maintenance here has been that and more this year, well, with a diff upgrade anyway. I get a lot of I Told You SO, but tother half happily forgets how much hers has depreciated in the same time!