Cost me $300-ish to get my oil temp gauge fixed up. The nut that screws into the engine mount was messed up and my mechanic wanted me to get er done up right. My temp gauge was reading fine but I reckon I got an overhaul as well. Ha ha. Rudy Aircraft Instruments. I also sent them my tach recently. Not promoting their service just stating where I sent my stuff. These are the people my Mechanic uses.
Good Luck !!
