Thermostat going out?

[lovemyiX]

What should be the temperature in my coolant reservoir, the same as the thermostat rating? I'm getting a reading of 150 deg. with my "thermopen" cooking sensor. The gauge used to be right at 12 o'clock but now it is at 11. I'm thinking it's the 'stat. Thanks

[dasmanschaft012]

maybe, it's a cheap part just replace it

[jeffnhiscars]

The reservoir temp is going to be less than internal coolant temps so don't go by that. Best to measure with an IR gun on the tstat housing and to also check the radiator for cool spots which means it needs attention

Use an 80c stat and your gauge should read below mid point except during extended idling

[ttrousdell]

I wouldnt worry about it.

[packratbimmer]

Confirm that the system is holding pressure. It will not operate the same if there are air leaks.

[lovemyiX]

Thanks everyone, all good advice. I am going to change the thermostat.