xantia cooling efficiency uphill

[Old-Guy]

Sounds like a failing thermostat to me. Symptoms much the same as our green 1.9 when we first had her. Although the original (11 year-old!) wax thermostat was opening at the correct temperature, it only opened a crack! Compared it with the new thermostat by gently heating them both up in an (old!) saucepan of water on the Kitchen hob. In my 40-odd years experience of second-hand cars, thermostats need changing every 4-5 years - they are no more reliable today than they were in the 1960s.

A new thermostat is vastly cheaper than a blown head gasket (or worse)!

[Mandrake]

Just be grateful thermostats haven't (yet!) been replaced by an ECU controlled motorised flap, (what could possibly go wrong there ? ) then you'd be pining for the days of good old fashioned wax thermostats.

[Old-Guy]

Just be grateful thermostats haven't (yet!) been replaced by an ECU controlled motorised flap, (what could possibly go wrong there ? ) then you'd be pining for the days of good old fashioned wax thermostats.

Oh, so true! The lack of ECUs (apart from the ABS which mostly behaves itself) and other electronic nonsense is a primary reason for resuscitating the Green Lady.

[Mandrake]

As much as we're critical of them when they fail, wax thermostats are surprisingly reliable given their simplicity, the importance of their function and the harsh environment in which they work. And when they do fail it tends to either be to stick open (failing on the side of caution) or a gradual failure that gives plenty of warning to the attentive.

There's probably a good reason why were still using them after all these years despite computer controlled systems taking over nearly everything else, and its probably not just that they're simple and cheap to make. As you point out though, a thermostat should be considered a consumable item with a finite life time.

[addo]

Mine's 130000km old, and still bang on. It's a Valeo, but the original Calorstat looked fine when replaced.

[John Plum]

I agree with you Old guy, and Simon.
I needed to get an overview first - didn't know if an exu interposed itself in the cooling somewhere.

Partially opening thermostat needs to be ruled out , so I'm whipping it out to see - or just replace it anyway.

Cheers folk!

[John Plum]

I did the thermostat. Probably still losing water, and so should check waterpump seal next.


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