Checking procedure

Fig 1: Identifying Regulator Until Pressure Gauge & Hissing Sound From Oil Filler Opening

Courtesy of VOLVO CARS OF NORTH AMERICA.

Adjust regulator until pressure gauge reads max. 0.3 bar (4.35 psi).
Gentle hissing sound can be heard from oil filler opening due to opening of an intake valve and leakage of cylinder pressure past piston rings.

Fig 2: Identifying Connection Points For Leakage Tests

Courtesy of VOLVO CARS OF NORTH AMERICA.

Check components and connections as per Checking components and Checking connections .
Coat connections with soapy water if unsure whether leakage is present.
Bubbles are permissible around throttle spindle.
Small bubbles are permissible between TB and intake hose (if of plastic). No bubbles are permissible with rubber hose.
Check for air leakage from EVAP valve. No leakage is permissible.