GM 4.3 Coolant Bypass

[George7941]

Where is it? There are no bypass hoses near the stat. Maybe it is an internal passage or maybe the heater core serves as a bypass. Does someone know?

This came up because I am in the process of installing a coolant filter (Baldwin 5134). I am installing an inline shutoff valve and the filter and valve will be in line with the heater core. If I keep the valve off in the summer, will it affect the bypass flow?

 

[FL_Rob]

It's on the back, right side intake manifold.It plumbs to the heater core if i'm remembering correctly.

 

[Chris142]

Should be a hose off the top of the wp. Kinda u shaped.

 

[George7941]

Thanks, Chris, exactly the way you described it. I don't know how I missed it. It is the one behind the idler pulley, at about the 4 O'clock position.

I have no coolant hoses at the back of the manifolds, just the heater supply and return hoses.