Porsche 928 S 1984 Owner's Manual page 33

Coolant temperature gauge
and warning light
Needle in white field - engine is cold
As long as needle is in white field, avoid
high speeds and high engine rpm, until en-
gine has reached normal operating tem-
perature. Do not lug the engine.
Needle in center striped field - normal
Under normal driving conditions, needle should
remain in center field. The needle may reach
the red field, especially at high engine loads,
but should return to "normal" when engine
load is reduced.
Needle in red field - warning
If needle enters the red field, the engine is
overheating. The central warning light will also
come on. Reduce speed and engine rpm. If
the needle does not return to the center field,
and the central warning light remains on, pull
off the road, turn off the engine and let it cool
down.
Coolant temperature warning light
If this light comes on, check whether the V-belt
driven mechanical fan is working. If the fan is
not working, the V-belt may be loose or broken.
The belt should be tensioned or replaced.
Do not continue to drive with a broken
V-belt.
On vehicles equipped with a factory installed
air conditioner, also check whether the electric
fan in front of the air conditioner is working.
WARNING
• Before you check anything in the engine
compartment, let the engine cool down.
Hot components can burn skin on con-
tact.
• The radiator fan switches on automati-
cally when the coolant reaches a certain
temperature and continues to run (even
with ignition off), until the coolant tem-
perature drops. Therefore, never touch
the fan blades as they will rotate spon-
taneously when the thermoswitch turns
the fan on.
• Be careful if you have to remove the cap
from a hot coolant fluid reservoir. Pro-
tect your hands, arms and face against
scalding. Use a thick rag and open the
cap carefully one turn to allow excess
pressure to escape before removing the
cap.
If the electric fan is not working, there may be
a malfunction in the temperature sensor switch
or in the electrical system. Check for a blown
fuse.
If the problem cannot be readily located, be
sure the engine has cooled down sufficiently.
Then drive to the nearest Porsche dealer, but
carefully watch the coolant temperature gauge
and the warning light. Try to avoid engine id-
ling, very low speeds and engine speeds in
excess of 4000 rpm (revolutions per minute).
For other details refer to "Cooling System".
31