Checking Air Intake System

Special Tools
981 4215
999 5544
999 5545

Preparations
- Check that all hoses are intact and are in the correct position with the hose clips tight.

Connect tools





- Disconnect the fresh air hose from the MAF sensor
- Connect the tool 999 5545 and the pressure regulator 999 5544 to the hose and tighten the hose clamp
- Use the hose clamp to block the crankcase ventilation hose
- Remove the oil filler cap
- Disconnect the bottom hose from the Canister Purge (CP) valve.

Checking procedure





- Adjust the regulator until the pressure gauge reads max. 0.3 bar
- A gentle hissing sound can be heard from the oil filler opening due to the opening of an intake valve and leakage of the cylinder pressure past the piston rings.
- Check the components and the connections as per sections Checking air and vacuum hoses, turbocharged engines
- Coat the connections with soapy water if unsure whether a leakage is present
- Bubbles are permissible around the throttle spindle
- Small bubbles are permissible between the Throttle Body (TB) and the intake hose (if of plastic). No bubbles are permissible with rubber hose
- Check for air leakage from the Canister Purge (CP) valve. No leakage is permissible.