Pontiac Sunbird Owner's Manual page 213

Service & Appearance Care
Adding Co~lant-Z~OL L4 Engine
( C o n r 7 y
To Add Coolant:
If you need more coolant, add the
proper
mix at the thermostat housing,
but only when the engine is cool.
Turning the radiator pressure
1
A
cap or the thermostat housing
pressure cap when the engine and
radiator are hot can allow
steam
and scalding liquids to blow out
and bum you badly. Never turn
either pressure cap-even a
little-when the engine and
radiator are hot.
1
.
When the engine is cool, remove the
thermostat housing pressure cap and
the thermostat.
Without pressing dom'on the
pressure cap, turn it slowly to the
left until it reaches a "stop."
If you hear a hiss, it means there is
still some pressure. Wait for the hiss
to stop. Then press down on the
pressure cap and continue turning it
to the left. Remove the pressure cap.
Take the thermostat out of the
housing.
A
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol,
and it will burn if the engine parts
are hot enough. Don't spill coolant
on a hot engine.