1.9 wbx running warm - late coolant system

[T25Convert]

Driving on mixed A roads up to around 6omph the van is getting warmer than ideal - not a full in overheat, just hotter than it should.

Pop the heater on full whack and it quickly cools off to what it should be running at.

System fully bled, full of antifreeze etc. When fan cuts in whilst in traffic, it does cool down.

So as heater bypasses thermostat do people think it's the stat or the radiator partially blocked? Or something else?!

[itchyfeet]

stats I'm reliably told almost always fail open so looks more like a blocked rad, try flushing it.

[what2do]

I've never had a rad fan come on whilst in traffic this time of year. Can't speak for others but that does sound unusual.

[bigherb]

stats I'm reliably told almost always fail open so looks more like a blocked rad, try flushing it.

No, Waxstats fail closed, only air cooled alcohol stats fail open.

[T25Convert]

Well a highly scientific test (involving a pan of water and my thermostat) shows that its not the thermostat.

New radiator on order, so look forward to fitting that when it turns up.

[itchyfeet]

stats I'm reliably told almost always fail open so looks more like a blocked rad, try flushing it.

No, Waxstats fail closed, only air cooled alcohol stats fail open.

mmm interesting I had one fail closed years ago and that was my understanding until I was corrected recently
I wil try and find the post.

[itchyfeet]

Ok so it wasn't on here but that reliable source of info called Facebook

Kevin is somebody who usually knows his sfuff as is Mark who runs a T3 workshop in Holland.

Thermostat fail by Paul_Barr, on Flickr

[T25Convert]

Ok so it wasn't on here but that reliable source of info called Facebook

Kevin is somebody who usually knows his sfuff as is Mark who runs a T3 workshop in Holland.

Thermostat fail by Paul_Barr, on Flickr

The wax stat in vauxhall astra G's fails open, and its very common. As its behind the timing belt (well done Vauxhall) the standard bodge is a renault 5 in hose stat in the top radiator hose.....

[T25Convert]

Well on closer inspection the radiator was rotten at the bottom, which can't have been helping.

New radiator in, local test run suggests much improvement. Just need to take it on a longer run to confirm.

[silverbullet]

FWIW, it depends on the thermostat design but I cant remember a stat failing open on any of my cars. The kettle test always seems to reveal partial or very sluggish opening when "heater on full and open the windows" was required.
Comparing a Vauxhall to a VW? Fromage and calcium carbonate spring to mind.

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