how to check for vacuum leaks in my BMW 5 Series F10/F11 (2010-2017)

Solution

1. Preparation

• Tools Required: OBD-II scanner, smoke machine (optional), propane torch, carburetor cleaner, safety gloves.
• Safety Warnings: Ensure the engine is off when inspecting components. Wear safety glasses and gloves when handling cleaning agents.

2. Visual Inspection

• Inspect all vacuum hoses for signs of wear, cracks, or disconnections.
• Check the intake manifold for any visible damage or loose bolts.
• Tighten any loose clamps or fittings.

3. Smoke Test

• Connect the smoke machine to a vacuum source (throttle body or intake).
• Introduce smoke and observe any escaping smoke from hoses or connections.
• Note the areas where smoke escapes, indicating a vacuum leak.

4. Propane Method

• Start the engine and let it idle.
• While the engine is running, carefully move a propane torch (unlit) around the intake manifold and vacuum line connections.
• Watch for any increase in engine RPM, which indicates a vacuum leak at that location.

5. Spray Test

• With the engine running, spray carburetor cleaner or soapy water around suspected vacuum connections.
• Look for changes in engine RPM or bubbling, which would signify a leak.