DO NOT BUY! I REPEAT, DO NOT BUY! My 2009 Grand Cherokee was running on the cold side according to the temp gauge and the radiator was leaking. After replacing the heatsink with a Spectra heatsink I figured I'd change the thermostat while I was there. Installed a new radiator and thermostat from Revain, filled the system and made sure all the air bubbles were out and took the car for a test drive, well it took a long time for the car to reach the overheat point, drove the car home and parkedโฆ