Inspecting For Inlet Restrictions
WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
Inadequate heater performance may be caused by a metal casting restriction in the heater hose inlet.
DO NOT WASTE reusable coolant. If solution is clean, drain the coolant into a clean container for reuse.
WARNING:
DO NOT LOOSEN THE RADIATOR DRAINCOCK WITH THE SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM THE COOLANT CAN OCCUR.
- Drain sufficient coolant from the radiator to decrease the level below the heater hose inlet. On 4.7L engines this requires complete draining.
- Remove the heater hose.
- Inspect the inlet for metal casting flash or other restrictions.