Failed Thermostat

A common failure point on the Toyota 2ZZ-powered Elise is the thermostat. The rubber seal around the valve moves and causes the thermostat to be stuck open. Symptoms include the engine being very slow to warm up, not being able to engage the high lift cam, and possibly a check engine light (CEL). Make sure to buy a replacement thermostat (not from Toyota) that doesn't have the interior rubber seal.

When installing the new thermostat, makes sure that the "jiggle valve" is oriented up so that air in the cooling system will escape paste the thermostat.



   Last update: Dec 7th, 2019