check for blockage, thermostat new temp sensor (blue) plus pipes, flush rad etc , are you fans kicking in ? if not fuses or relay, ... ???? for starters... has it run hot always or just started doing it ?....... is it using water ?

mine runs hot and has had new everything but never goes in the red and never loses any water... also changed my rad and new fans and switch etc .. guess its may be a dodgy guage....

iirc the thermostat opens at 86 deg ??? maybe wrong... could be a little higher.....