Saab 1987 900 Owner's Manual page 44

42 Technical description
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Underhood components
10.
1. Dipstick, manual
11.
transmission
*
12.
2. Power steering reservoir
13.
(16 valve)
14.
3. Water pump
15.
4. Alternator
5. Brake fluid reservoir
16.
6. Coolant tank
17.
7. Engine oil dipstick, filter
hole
lB.
B.
Fuel filter (B valve)
*)
(beneath rear a'Cle, 16
valve)
9. Electronic ignition module
Washer fluid reservoir
Battery
Turbocharger (Turbo only)
Ignition distributor
Ignition coil
Air flow meter (16 valve)
Fuel distributor (B valve)
Intercooler (Turbo only)
Cruise control vacuum
pump
Power steering pump
Automatic transmission dip-
stick protrudes ahead of the
engine
near the upper
radiator hose.
Engine
The Saab 900 has a four cylinder in-line
liquid cooled engine with a roller chain dri-
ven overhead camshaft(s).
Two camshafts are used on 16 valve engines
which have two intake valves and two
exhaust valves per cylinder for greater vol-
umetric efficiency. A single camshaft and
two valves per cylinder are used on 8 valve
engines.
The engine block is cast iron and is canted
45° to the right. The light alloy cylinder
head is of crossflow type, i.e. with inlet
ports on one side and exhaust ports on the
other. The crankshaft is supported in five
main bearings and drives the oil pump. The
ignition distributor is driven directly by the
camshaft. The air intake preheater is ther-
mostatically controlled on 8 valve engines.
16 valve engines have a coolant heated
throttle housing.
16 valve engines are equipped with an au-
tomatic idle control (AIC) system which
adjusts the engine idle according to the en-
gine loading. 8 valve engines have a fixed
idle circuit.
Emission control systems '
The 1987 Saab has three distinct systems for
controlling emissions to the athmosphere.
The sections that follow briefly describe
these systems.
I The Exhaust Emission Control System