Poor Heater Performance

Some owners of the 2006 Chevrolet Silverado or GMC Sierra with 6.6L Engine RPO LBZ may comment on poor heater performance. During normal diagnostics, both heater hoses may be cold. This may be caused by the heater hose being pinched/kinked at the lower radiator hose (fig. 11).

To correct this condition, drain the coolant system and reroute the heater hose to eliminate the pinch/kink (fig. 12).

TIP: There is a white line on the heater hose. It should be centered to the front of the hard tube.

- Thanks to Jim Will