GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 Jimmy - 2WD 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Odor Diagnosis

Problem

Action

    • A musty smell is present.
    • Water leaks from the body.

Seal the body.

    • A musty smell is present.
    • The evaporator drain is clogged.

Clean the drain.

    • A musty smell is present.
    • Mold or mildew is present¹.

Clean the evaporator.

    • A coolant smell is present.
    • The anti-freeze leaks.
  1. Inspect the heater core.
  2. Inspect the pipes.
  3. Inspect the hoses.
  4. Repair or replace the components as necessary.

The refrigerant oil leaks.

Inspect the evaporator core. Repair or replace the evaporator core as necessary. Refer to Air Conditioning Evaporator Core Replacement

¹Under certain climate and operating conditions, a musty odor develops from mold growth in the evaporator core face. This odor is generally temporary. As climate conditions change the odor will disappear and repair automatically. If the odor persists, remove the evaporator core. Clean the evaporator core face with the appropriate cleaner.