Pontiac Fiero 1988 Service Manual page 353

6B-4 ENGINE COOLING
NOTICE:
If recommended quality antifreeze is
used, supplemental inhibitors or additives claim-
ing to provide increased cooling capability are
not necessary. They may be detrimental to the
efficient operation of the system, and represent
an unnecessary operating expense.
Every 12 months or 15,000 miles, the cooling
system should be serviced as follows:
1. Wash radiator cap and filler neck with clean
water.
2. Check coolant for proper level and freeze
protection.
3. Pressure test system and radiator cap for proper
pressure holding capacity, 103 kPa (15 psi). If
replacement of cap is required, use the proper
cap specified for car model.
4. Tighten hose clamps and inspect all hoses.
Replace hoses whenever checked, swollen or
otherwise deteriorated.
5. Clean frontal area of radiator core and air condi-
tioning condenser.
DRAINING AND REFILLING THE COOLING
SYSTEM
Replace hoses every 24 months or 30,000 miles,
or earlier if cracked, swollen or otherwise deterio-
rated. Every two years or 30,000 miles, whichever
first occurs, the cooling system should be flushed and
refilled using the following recommended procedure:
1. Remove radiator cap, or thermostat housing cap
(VIN K, M, R and U), when engine is cool by:
a. Slowly rotating cap counterclockwise to
detent. (Do not press down while
rotating.)
b. Wait until any residual pressure (indicated
by a hissing sound) is relieved.
c. After all hissing ceases, press down on
cap while continuing to rotate counter-
clockwise.
CAUTION: To avoid the danger of being
burned, do not remove radiator cap
while engine and radiator are still hot.
Scalding fluid and steam may be blown
out under pressure.
2. Remove the thermostat by using the wire handle
to lift it out of the housing (VIN K, M, R
and U).
3. With the thermostat removed, reinstall the
thermostat housing cap (VIN K, M, R and U).
4. Open radiator drain valve and block drain plugs
to drain coolant. On VIN R and 9 (P carline)
engines, open coolant pipe plugs.
5. Close valve. Reinstall drain plugs, and add suf-
ficient water to fill system.
6. Run engine, drain and refill the system, as
described in steps 4 and 5 a sufficient number of
times, until the drained liquid is nearly
colorless.
IT! Important
• BLOCK DRIVE WHEELS, place trans-
mission in PARK (automatic transmis-
s i o n ) or N E U T R A L
( m a n u a l
transmission) and set the parking brake.
7. Allow system to drain completely. Then close
radiator drain valve tightly, and reinstall block
drain plugs.
8. Remove recovery cap leaving hoses in place.
Remove coolant recovery tank and empty of
fluid. Flush tank with clean water, drain and
reinstall.
9. Add sufficient ethylene glycol coolant, meeting
GM specification 1825-M, to provide the
required freezing and corrosion protection — at
least 50 percent solution -37°C (-34TF). Fill
radiator to the base of the radiator fill neck aiid
add sufficient coolant to the recovery tank to
raise level to the "FULL" mark. Reinstall recov-
ery tank cap.
10. Run engine, with radiator cap or thermostat
housing cap removed, until normal operating
temperature is reached. (Radiator upper hose
becomes hot.)
11. With engine idling, add coolant until level
reaches bottom of filler neck and reinstall cap,
making certain arrows line up with overflow
tube.
CAUTION: Under some conditions, the
ethylene glycol in engine coolant is
flammable. To help avoid being burned
when adding coolant, DO NOT spill it on
the exhaust system or hot engine parts.
It is the owner's responsibility to keep the freeze
protection at a level appropriate to the tempera-
tures which may occur in the area of vehicle
operation.
a. Maintain cooling system freeze protection
at -37°C (-34°F), to ensure protection
against corrosion and loss of coolant from
boiling, even though freezing tempera-
tures are not expected.
b. Add ethylene glycol base coolant that
meets GM Specification 1825-M, when
coolant additions are required because of
coolant loss, or to provide additional pro-
tection against freezing at temperatures
lower than -37°C (~34°F).
NOTICE:
Alcohol or methanol base coolants, or
plain water, are not recommended at any time.