Pontiac Fiero 1988 Service Manual page 355

6B-6 ENGINE COOLING
BOILING/ENGINE O V E R H E A T / ENGSNE COOLANT L O S S
loose
CHECK FAN BELT/WATER
PUMP BELT TENSION
TIGHTEN TO SPEC.
collapsed
k.
CHECK FOR COLLAPSED
UPPER OR LOWER
RADIATOR HOSE
REPLACE
yes
o.k.
DIRT, BUGS, BENT FINS,
ETC. BLOCKING RADIATOR
OR A/C CONDENSER
CLEAN OR STRAIGHTEN
obstructed
o.k.
CHECK FOR LICENSE PLATES,
AUX. OIL COOLERS, ETC, OR
BENT/DAMAGED FAN
REMOVE OBSTRUCTION
OR REPLACE FAN
o.k.
CHECK COOLANT LEVEL
REPLACE
bad
o.k.
CHECK PRESSURE CAP-
use tester per chassis
service manual
low
ADD
o.k.
CHECK FOR PROPER ANTI-
FREEZE PROTECTION
CHECK BULB
REPLACE
REPLACE
bad
o.k.
CHECK HOT LIGHT OR
COOLANT TEMP. GAUGE
good
o.k.
CHECK SENDING UNIT
SYSTEM O.K.
bad
REPLACE
~ 1
o.k.
PERFORM ON-CAR THERMO-
STAT CHECK-see Thermostat Di-
agnostic Chart (chart 2)
SYSTEM O.K.
REPLACE RELAY, FAN,
OR FAN SWITCH?
equipped
y e s
SYSTEM O.K.
SYSTEM O.K.
yes
o.k.
CHECK ELECTRIC COOLING
FAN IF EQUIPPED-(see pg. 5 for
single speed fan or pg. 8
for dual speed fan under
"ELECTRICAL DIAGNOSIS")
no
not equipped
ANY FIXES ABOVE
no
If none of the above required re-
pair, the problem is out of the ordi-
nary or of a major nature. Listed
on chart 3 are two groups of prob-
lem areas that should be checked
in the order listed.
low
no
VISUAL SYSTEM CHECK
LEAKS—-Check hoses, radia-
tor, clamps, water pump, ther-
mostat housing, rad. drain,
soft plugs, heater water valve,
heater core
FOAMING COOLANT—
Observe in filler neck after en-
gine warmup
OVERFLOW S Y S T E M -
A. Check gasket in pressure
cap
B. Check for leaks in hoses,
clamps, overflow bottle,
filler neck nipple
C. Check for obstructions in
hose between radiator and
bottle
REPAIR OR
REPLACE DEFECTS
PRESSURE CHECK
SYSTEM
Install cap checker on rad.
filler neck and pressurize to
rated pressure.
holds
I
doesn't
hold
ANY RE-
PAIRS ?
REPAIR
LEAKS
yes
SYSTEM
O.K.
G20002 6B
Figure 5 Cooling System Diagnosis Chart (2 of 3)