why does my Volvo XC90 make a whirring noise when starting?

Solution

1. Preparation

• Ensure the vehicle is in "Park" or "Neutral" and set the parking brake.
• Disconnect the negative battery terminal to prevent electric shock.

2. Battery and Connections

• Inspect and Clean Battery Terminals:

  • Remove the positive and then the negative terminal from the battery.
  • Clean any corrosion using a wire brush and a mixture of baking soda and water.
  • Reconnect the terminals securely.

• Replace the Battery (if necessary):

  • If the battery voltage is below 12.4V, replace it with a new battery of the same specifications.

3. Starter Motor Inspection

• Remove Starter Motor:

  • Locate the starter (usually at the engine block near the transmission).
  • Disconnect the electrical connectors from the starter.
  • Remove the mounting bolts using a socket set.
  • Carefully extract the starter motor from its housing.

• Test the Starter Motor:

  • Use a multimeter to check for continuity and proper voltage at the starter terminals.
  • If faulty, replace with a compatible starter motor.

4. Replace Starter Relay

• Access the Relay:

  • Locate the fuse box (often under the dashboard or in the engine compartment).
  • Identify the starter relay (refer to the vehicle manual for location).

• Replace the Relay:

  • Remove the old relay and install a new relay of the same type.

5. Reassemble and Test

• Reconnect all components in reverse order.
• Reconnect the negative battery terminal.
• Start the vehicle to check if the whirring noise persists.