Thermostat problem ?

[Marc]

Hi everyone ,

I have a Zafira 1.9 ctdi 150. I’m not sure if I have a thermostat problem . It seems to be sitting around 78c. It does get upto 84 at its highest but then goes back down to 78. The coolant pipe stays cold until 78 though. It doesn’t give any codes though or warning lights . Can anyone help please ?

[Vauxhall Owners Club]

Hi....welcome to the Club

88 degrees Centigrade is the normal opening temperature for the thermostat

Anything up and around that figure for an engine operating temperature is fine.

If it is a lower coolant pipe then that is also fine as it is circulating in cold air and lower part of radiator.

If the hose feels soft (e.g not slightly compressed with coolant) within it the maybe you have air trapped in the system

[Marc]

1 hour ago, Vauxhall Owners Club said:

Hi....welcome to the Club

88 degrees Centigrade is the normal opening temperature for the thermostat

Anything up and around that figure for an engine operating temperature is fine.

If it is a lower coolant pipe then that is also fine as it is circulating in cold air and lower part of radiator.

If the hose feels soft (e.g not slightly compressed with coolant) within it the maybe you have air trapped in the system

Hi, thankyou for the reply . Yeah the bottom pipe stays cold until around 78c like I’ve said , so you think it might be ok?  I did a flush on it this weekend but it’s made no difference. MAybe I’m just overthinking it ?only reason I checked was I had intermittent cold air in the heaters but I topped the coolant up and it’s been fine . How could I go about trying to get air out of the system ? 

[Vauxhall Owners Club]

The air should eventually rise to the highest point which could be the coolant expansion tank.
If it continues to draw air into the system then replace the coolant pressure cap which may be below par