My 05 Mini Cooper S keeps throwing a p0128 code. Changed thermostat housing twice and thermostat twice. Changed temp sensor once. Cleared code, nothing. Then the coolant tank was leaking and ended up changing that to aluminum one. Temp used to be in the middle before I changed the thermostat, now it only a quarter below. All thermostat I replaced was OEM or aftermarket, but all rated 195. Any suggestions?

 

What brand sensor did you install? Sometimes where a cheaper mechanical ebay special may work well, the cheaper ebay electrical items can be junk right out of the box,

 

I believe it was an eBay one.