OK to remove thermostat?

My mechanic wants to remove thermostat from my car, 2004 model Rav4, should I allow him?

Only if he replaces it with a new one. If there are cooling problems they need to be addressed. The thermostat plays a critical role in engine performance.


What he said (above).

Don’t pull the thermostat without replacing it.

I would agree 100% with the comments above, but I’ll add that you need a new mechanic, right away.


Why does your mechanic want to remove it? Just curious…

Removing the thermostat would result in the engine overheating due to coolant continually cycling through the open bypass circuit. I also suggest you find another mechanic.

Actually I had removed my thermostat before then My radiator keeps cracking when ever I go on long journeys.
However now am understanding that it’s not safe.

Before my posting from last December I checked and found that your engine has a by-pass thermostat which means it has 2 functions. Like all previous thermostats the Rav4’s opens and closes to control coolant passing through the radiator but it also has a tail piece on the plunger which opens and closes a by-pass in the block which keeps coolant circulating in the block whenever the passage to the radiator is closed. When a by-pass thermostat is removed the coolant will mostly circulate inside the block without passing through the radiator under most driving conditions. If your engine is not overheating without a proper thermostat you’re lucky so far. Repeatedly blowing the radiator would indicate that the head gasket is likely blown. Operating an engine without a thermostat was common but costly before 1980 but very costly and to be avoided for many reasons on computer controlled models that are on the roads today.

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