- On water outlet housing at front of engine
1987-95 5.0L, 5.7L, and 7.4L V8
- On intake manifold in front of carburetor
1988-95 6.2L Diesel V8
- On intake manifold behind injection pump
1996-02 2.2L, 4.3L, and 5.0L V8
- On intake manifold behind throttle body
1996-02 5.7L and 7.4L V8
- On intake manifold on driver side
1999-02 6.5L Diesel V8
- On intake manifold in front of fuel injection pump
2003-13 4.3L, 4.8L, 5.3L, and 6.0L V8
- On intake manifold behind throttle body
2003-13 6.0L, 6.2L, and 7.0L LS2, LS3, LS7 V8
- Front center of the engine, inside the valley (under intake manifold)
2007-13 6.6L Duramax V8 Diesel
- On the driver's side of the engine below the intake manifold, above the fuel filter
