With outside temps falling here I'm pretty sure I have all the symptoms of a thermostat soft fail and just wanted some confirmation.
Symptoms: car takes a while to heat up to center on the gauge, cruising at highway speeds causes temp gauge to move off center to the left (to what would be the 75C hash mark), interior heat is weak and gets cooler as the temp gauge moves to the left. On the plus side temp gauge never moves to right of center.
No CELs, fault codes showing or pending. Should there be?
PO says radiator, expansion tank, and water pump replaced after a minor driver's front meets rear end of other car incident earlier this year. But no paperwork. Radiator, expansion tank look new. From what I can see upper hose and thermostat housing have the bmw logo and 03 date code which would be original. No leaks or noises. Confusing as to why if WP was replaced you wouldn't replace the thermostat and other bits while in there but so be it.