For several years, it's been running cold (i.e. no heat, temperature gauge at 8 o'clock.) in the winter.
More recently, it also runs hot (temperature gauge at 10 o'clock) in the summer.
Anyone car to try a diagnosis?
Coolant level is OK, changed last year. No leaks. Hoses and thermostat are original. Water pump replaced at the 180K timing belt service.
I didn't worry much about running cold, as I get an oil light flicker when idling and warm, but running hot could finally kill the car.