why is my Toyota RAV4 Fifth Generation (2019-present) making a hissing noise

Solution

1. Preparation

• Gather necessary tools and ensure the vehicle is parked on a flat surface.
• Disconnect the negative battery terminal for safety.

2. Inspect and Replace Vacuum Hoses

• Sub-steps:
  1. Locate all vacuum hoses connected to the intake manifold.
  2. Check for any visible cracks or loose connections.
  3. If any hoses are damaged, remove them using pliers and replace them with new hoses.
  4. Reconnect all vacuum lines securely and ensure tight fits.

3. Repair Exhaust Leaks

• Sub-steps:
  1. Identify the source of the leak by inspecting exhaust components visually and using the stethoscope.
  2. If a gasket is damaged (e.g., at the manifold), remove the affected component (flange or manifold) using a socket set.
  3. Replace the gasket with a new, OEM-spec gasket.
  4. Reassemble the exhaust components and tighten to manufacturer specifications (usually around 15-20 ft-lbs, check for specific values).

4. Service the AC System (if applicable)

• Sub-steps:
  1. Inspect the AC compressor for any signs of damage or noise.
  2. If the compressor is faulty, disconnect the AC lines after recovering refrigerant using an AC recovery machine.
  3. Remove the compressor using the appropriate socket size, and replace it with a new unit.
  4. Reinstall the compressor, reconnect all lines, and recharge the AC system with the specified refrigerant.