PSU Taco85
Well-Known Member
So what is the targeted benefit from bypassing the heater core?
the thermostat is set to 203° in this pig, and the engine likes to run hot. I’ve heard that it will drastically reduce the air temps on a hot summer day with the AC on. Some of the newer trucks came with it from the factory, although it only bypasses one side of the core. Bypassing both lines will allow the same coolant flow through the rest of the engine and keep the same load on the water pump during the transition, hopefully maximizing its life and minimizing any cavitation.
My buddy send me a pic of his 2003 earlier so I could get the hose routing squared away, you can see his had a bypass
