Saab 5-Sep Automobile User Manual


 
152 Starting and driving
One of the advantages of the system is
that it enables the engine to be run
safely on lower-grade fuel, although not
lower than AON 87.
The maximum boost pressure is
adjusted automatically to the knocking
or pinging tendency of the engine.
Occasional, short-lived knocking when
the engine is under a heavy load is per-
fectly normal; the extent will depend on
the grade of fuel in the tank.
Isolated instances of knocking are
more likely to occur with low-octane
fuel. This controlled form of knocking,
followed by a reduction in the boost
pressure, is a sign that the wastegate is
functioning and is perfectly safe for the
engine.
Important considerations with cata-
lytic converters
The catalytic converter is an emission-con-
trol device incorporated in the car’s exhaust
system. It consists of a metal canister with a
honeycomb insert, the cells of which have
walls coated in a catalytic layer (mixture of
precious metals).
To ensure that the catalytic converter con-
tinues to function properly, and also to avoid
damage to the converter and its associated
components, the following points must be
observed:
Have the car serviced regularly in accor-
dance with the service program. The fuel
and ignition systems are particularly
important in this context.
Always be alert to any misfiring of the
engine (not running on all cylinders) and
any loss of power or performance. At the
first sign of a malfunction, reduce speed
and take the car to an authorized Saab
dealer as soon as possible.
If the engine fails to start (in very cold
weather or if the battery is flat), the car can
be push started (manual gearbox only) or
started using jumper cables to a donor
NOTICE
If the engine sounds strange there is a
fault in the system. Have the car
checked without delay by an autho-
rized Saab dealer.
The use of fuel with too low an octane
rating can cause serious engine dam-
age.
WARNING
If the engine is being run with the car on a
rolling road or dynamometer, longer than
for a standard state emission inspection,
to ensure adequate cooling, air must be
blown into the engine compartment and
under the car at a rate equivalent to the
ram-air effect that would be obtained at
the corresponding road speed.
NOTICE
Use only unleaded gasoline. Leaded gas-
oline is detrimental to the catalyst and
oxygen sensor and will seriously impair
the function of the catalytic converter.