Noise Diagnosis - Blower Motor

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Step	Action	Yes	No
DEFINITION: Noise originating from the blower motor.
1	Were you sent here from the HVAC Symptoms?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Sit inside the vehicle. Close the vehicle doors and windows. Turn ON the ignition, with the engine OFF. Cycle the blower motor through all of the speeds in order to determine where and when the noise occurs. Did you hear a noise during the blower operation?	Go to Step 3	Go to Step 10
3	Does the noise vary with the blower speed?	Go to Step 4	Go to Step 10
4	Inspect for excessive vibration at each blower motor speed by feeling the blower case. Is excess vibration present?	Go to Step 5	Go to Step 6
5	IMPORTANT: Inspect the blower motor impeller cavity through the access hole under the passenger compartment air filter. Examine the blower motor cavity for deposits of foreign material.Did you find foreign material?	Go to Step 7	Go to Step 6
6	Remove the blower motor. Refer to Blower Motor Replacement . Inspect the blower motor for the following conditions: Cracked blades A loose impeller retainer Improper impeller alignment Did you find any of these conditions?	Go to Step 8	Go to Step 10
7	Remove the foreign material. Is the action complete?	Go to Step 10	-
8	Replace the blower motor. Refer to Blower Motor Replacement . Is the replacement complete?	Go to Step 10	-
9	Install the blower motor. Refer to Blower Motor Replacement . Is the action complete?	Go to Step 10	-
10	Operate the system in order to verify the repair. Does the system operate correctly?	System OK	Go to Step 2