Is it the correct temp reading? The car may all be fine just not reading correctly. Maybe sensor or display fault
Hi dan.
The temp reading always corresponds to what I am feeling coming from the heater. Hot at idle and cool when moving.
Yorkie.
Is it the correct temp reading? The car may all be fine just not reading correctly. Maybe sensor or display fault
Sister in law has a 2006 1.6 which was having similar problems but then boiled up on the motorway resulting in a new head gasket. It blew another head gasket and so went back in and this time had the head skimmed. Within no time at all the gasket blew again completely screwing the engine and a new engine being sourced.
I think Vauxhall traced the fault back to one of the water pipes which had a leak which got worse under pressure
Her latest problem with this car is with the horn comes on when the head lights are on so she can't use it after dark until the car goes back in on the 30th
Hi EF.
Never had to put a drop of water in it since I got it. Pretty sure no leaks present. Gasket seems fine.
Yorkie.
What are you using for coolant? and when was the last time you had the system flushed out?~Muir
As said check the electrical connectors /leads.From experience on older astray there is a small connector on the inlet manifold which would measure the temp. Might be worth checking this or plugging it in to a diagnostic kit to check.
good luck.
I'm not sure how it could be electrical. The heater output appears to match the temp reading, so it doesn't sound like a fault in the temp reading or in the heater fan. The cooling fan (assuming it's electric) shouldn't be running at motorway speeds anyway, so a failure there would act up at the opposite time.
Water pump or gasket issues would be showing additional symptoms.
That really sounds like a stuck-open thermostat. It's possible the replacement was duff out of the box....
(Caveat: while I maintain several classic cars, I'm not a professional mechanic.)
Cheers,
Jeff.

It's an information highway world now, one of your lanes (electrical) has a plastic bobby holding things up!!!check all your leads are contacting properly.
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Hi Andy.
anti-freeze and water mix. Coolant was all changed when thermostat was changed. We have coolant a very nice shade of pink now. Not sure if it was actually flushed under pressure but it is all new coolant and the old coolant was clean.
Thanks.
Yorkie.
Consider a complete coolant system flush. ~Muir
Zafira 2 DTI's are notorious for this, my two have both taken ages to warm up and never run anywhere near the proper temperature. I changed numerous thermostats and no change. You can always check the thermostatby placing in a pan of cold water and bringing up to the boil and then cooling to see if it opens and closes ok. You could try replacing the temp sender as it might be faulty, did that with mind and went totally hay wire so if you do keep the old one and be prepared to swap it on the road side. Best idea is to blank of a portion of the rad with a sheet of something, plastic/ally or alike.
D
cold when moving, never shows 90deg
heats up when still, fan kicks in at right temp
with those symptoms it can only be a faulty thermostat
it is stuck open meaning the still warming coolant is flowing through the radiator and cooling down when on the move
Not the end of the world but long term not a great idea as the ECU uses coolant temp in delivering the fuel mix
you do not want to run it cool for any length of time IMO
bodging the radiator is a poor way of fixing an otherwise simple problem
who did the stat job and what parts did they use?