Emissions - Crankcase Ventilation System Testing
NO: 25-149-BDATE: 2-20-2006
MODEL/ YEAR: C70 1999-2002
S70 1999-2000
S60 2001-2002
V70 1999-2002
V70XC 1999-2001
S80 1999-2001
SUBJECT: Checking Crankcase Ventilation System
REFERENCE: VIDA STB-148A
This TNN supersedes the previous TNN 25-149-B dated 12-06-2005. Please update your files.
DESCRIPTION:
This TNN describes a new method for checking the functionality of crankcase ventilation.
Measuring pressure in the crankcase
Measure with the engine:
^ At Operating temperature (Fully warmed
up).
^ With the engine running at idle speed.
^ With the A/C Off.
^ With all Electrical Accessories off (Heated
seats, Lights etc.)
The Battery and Charging system must be in
good condition.
Note! Specification given is for Sea Level,
(Higher Altitude will reduce the vacuum
reading slightly).
Remove the dipstick and connect the
pressure gauge (manometer) 999 7226 as
illustrated.
Measuring pressure in the crankcase
5-cyl Turbo and 6-cyl Turbo
Read the value on the gauge:
The value for clean crankcase ventilation
is -0.2 kPa or lower.
If the gauge shows a value of -0.2 to
0.0 kPa or a positive value, The crankcase
ventilation is partially or fully clogged and
must be cleaned as described in:
TNN 25-149-C, Cleaning the Crankcase
Ventilation.
Note:
The gauge should not be used to verify the cleaning of the crankcase ventilation hose and banjo fitting. The gauge reading may also be affected by other conditions in the engine like a leaking oil filler cap gasket, and should only be used as an indication that further diagnosis should be performed.
Measuring pressure in the crankcase
6-cyl Non-turbo
Read the value on the gauge:
The value should read approximately 0.0
kPa.
Gently squeeze the hose between the "T"
fitting and the intake hose using a hose
clamp pliers similar to the ones shown in the
illustration.
Note:
Be careful not to close off the hose completely because this will damage the gauge.
If negative pressure can be seen on the
gauge the crankcase ventilation is clean and
no further work is needed.
If no or very little negative pressure is seen,
the crankcase ventilation is partially or fully
clogged and must be cleaned as described
in:
TNN 25-149-C, Cleaning the Crankcase
Ventilation.
Note:
The gauge should not be used to verify the cleaning of the crankcase ventilation hose. The gauge reading may also be affected by other conditions in the engine like a leaking oil filler cap gasket, and should only be used as an indication that further diagnosis should be performed.