What this test proves

Check the isolated charge-air path for pressure leakage without operating the turbocharger.

Tools

  • Rated charge-air test adapters with secure retention
  • Regulated air/smoke source and pressure gauge
  • OEM isolation and pressure limits

Preparation and precautions

  • Engine off and cooled. Identify which sensors, crankcase paths and valves must be isolated.
  • Secure plugs against ejection and stay out of their path. Never use unrestricted compressed air.

Connections

  • Connect to the specified isolated charge-air section, with the required regulated source, gauge and relief arrangement.

Equipment settings

  • Increase pressure only to the manufacturer’s test limit, which may be lower than operating boost.

Test sequence

  1. Inspect hoses and intercooler externally.
  2. Pressurize gradually.
  3. Locate leakage using the approved detection method.
  4. Account for permitted valve leakage and temperature effects.
  5. Fully vent before removing adapters; restore all connections.

Expected signal / readings

The selected section should meet its specified leakage or decay allowance.

Interpreting results

  • A detected joint leak can explain lost boost but does not rule out control or turbo faults.
  • Testing through an open engine valve may create misleading decay.

Common mistakes

  • Using operating boost as the test-pressure limit
  • Standing in front of a test plug
  • Pressurizing the crankcase through an unisolated path