Inline Thermostat Basics

Inline Thermostat Basics

What is it?

 An inline thermostat is a thermostat that is mounted in the middle of a radiator hose instead of on the engine block.   Moving off the block can improve the ability to access the thermostat. It is a more universal style thermostat, so there is a wide selection of temperature elements available.



Where does it go?


The best location is usually in the top radiator hose in a section near the highest point of the hose. It can be in a straight section or a corner, it is best to have it in a position where the bolts are easily accessed.




What about radiator hose sizes?


Most vehicles have radiator hoses that are either around 1.5" i.d. or 1.25-1.38 i.d. (with the only exception being small four cylinder engines). If are replacing a factory thermostat system with an inline thermostat, you just need to understand what size your original hose is. However, if you are swapping an engine in to a vehicle of a different generation or different manufacturer, you may have different sizes on the engine and the radiator, necessitating an adapter housing kit with one half in the large size and one half in the medium size.



Bypass/sensor/bleed ports


Some vehicles come with bypass port hoses coming off of the factory thermostat housing, we do have housings with threaded fitments for fitting threaded hose barbs for bypass lines. These threaded ports can also be used for installing aftermarket or factory temperature sensors, or for as simply bleeding air out of the cooling system.


Thermostat elements


Our thermostat elements are available in a wide variety of temperature settings. All are top quality elements with pre-sized bleed ports for allowing a small amount of coolant flow to maintain smooth opening and closing and temperatures.





Different angles for installation in different bends in hoses, different size ports for installation of different size sensors or bypass hoses, different size hose connections.




Anything Else?


Of course, once you install an inline thermostat you need to remove your factory thermostat.  Usually this involves just removing the factory thermostat housing outlet, removing the thermostat element, and re-installing the factory thermostat housing outlet with no element inside.