What a Thermostat Jiggle Pin Does
Understanding the Purpose of a Thermostat Jiggle Pin
The thermostat jiggle pin acts like a bleeder valve to prevent trapped air from insulating the wax pellet
How does air get into the cooling system?
Any time you flush or drain your coolant you can get air in the system. You can also get air in the coolant if your water pump is creating cavitation, or you have a cooling system leak.
When installed vertically, the pin can be located in any orientation. However, when the thermostat is installed in a horizontal position, the it should always be turned so it’s in the 12:00 o’clock position.
If the pin is located in any other position in a horizontal installation, the air around the thermostat’s wax element could act like an insulator, preventing the thermostat from opening at the right time. That could cause your engine to overheat.
For more information on how a thermostat works, see this post. For more cooling system service posts, click here
©, 2021 Rick Muscoplat
Posted on by Rick Muscoplat