Pontiac Fiero 1988 Service Manual page 354

ENGINE COOLING
6B-5
ENGINE COOLING SYSTEM COMPLAINT
TO AVOID NEEDLESS TIME AND COST IN DIAGNOSING COOLING SYSTEM COMPLAINTS, THE CUSTOMER
SHOULD BE QUESTIONED ABOUT DRIVING CONDITIONS THAT PLACE ABNORMAL LOADS ON THE COOLING
SYSTEM.
1. DOES OVERHEATING OCCUR WHILE PULLING A TRAILER?
IF ANSWER IS " Y E S " — HOW HEAVY IS TRAILER? IF TRAILER WEIGHT IS GREATER THAN 1,000 LBS. & CAR IS EQUIPPED
WITH NORMAL DUTY COOLING SYSTEM, A HEAVY DUTY COOLING PACKAGE IS REQUIRED (PER MFR'S TRAILER HAULING
SPECS.). FURTHER DIAGNOSTIC CHECKS SHOULD NOT BE REQUIRED.
2. IS CAR EQUIPPED WITH ADD—ON OR AFTER MARKET AIR CONDITIONING SYSTEM?
IF ANSWER IS " Y E S " — WAS HEAVY DUTY RADIATOR INSTALLED WITH THE SYSTEM? IF NOT, INSTALL HEAVY DUTY AIR
CONDITIONING RADIATOR FOR THE CAR MODEL INVOLVED (PER MANUFACTURER'S SPECS.). FURTHER DIAGNOSTIC
CHECKS SHOULD NOT BE REQUIRED.
3. IS OVERHEATING OCCURRING AFTER PROLONGED IDLE, IN GEAR, A/C SYSTEM OPERATING?
IF ANSWER IS " Y E S " — INSTRUCT OWNER ON DRIVING TECHNIQUES THAT WOULD AVOID OVERHEATING SUCH AS:
a. IDLE IN NEUTRAL AS MUCH AS POSSIBLE — INCREASE ENGINE R.P.M. TO GET HIGHER AIR FLOW & WATER
FLOW THROUGH RADIATOR.
b. TURN A/C SYSTEM OFF DURING EXTENDED IDLES IF OVERHEATING IS INDICATED BY HOT LIGHT OR TEMP. GAGE.
FURTHER DIAGNOSTIC CHECKS SHOULD NOT BE REQUIRED.
4. IS OVERHEATING OCCURRING AFTER PROLONGED DRIVING IN SLOW CITY TRAFFIC, TRAFFIC JAMS,
GARAGES, ETC.?
IF ANSWER IS " Y E S " — INSTRUCT OWNER ON DRIVING TECHNIQUES THAT WOULD AVOID OVERHEATING — SAME AS
FOR PROLONGED IDLES — NO. 3 FURTHER DIAGNOSTIC CHECKS SHOULD NOT BE REQUIRED.
IF NONE OF THE ABOVE APPLY, GO TO DIAGNOSTIC CHART
TO EFFECTIVELY USE THIS CHART, QUESTION THE OWNER TO DETERMINE WHICH OF THE FOLLOWING
(3) CATEGORIES APPLIES TO THE COMPLAINT:
1. HOT LIGHT OR HOT INDICATION ON TEMPERATURE GAGE
2. BOILING
3. COOLANT LOSS
1. IF COMPLAINT IS HOT LIGHT OR HOT INDICATION ON TEMPERATURE GAGE —
WAS HOT LIGHT ACCOMPANIED BY BOILING? IF ANSWER IS " Y E S " , GO TO BOILING ON CHART
IF ANSWER IS "NO", GO TO HOT LIGHT ON CHART
2. IF COMPLAINT IS BOILING — GO TO BOILING ON CHART
IF PROBLEM REMAINS, GO TO COOLING FAN DIAGNOSIS SECTION 8 (IF SO EQUIPPED).
3. IF COMPLAINT IS COOLANT LOSS —
DETERMINE IF CUSTOMER IS OVERFILLING THE SYSTEM, THIS WOULD NORMALLY RESULT IN SMALL AMOUNTS OF
COOLANT LOSS THROUGH THE OVERFLOW TUBE. IF THIS IS THE CASE, INSTRUCT THE CUSTOMER ON PROPER FILL
LEVEL & NO FURTHER DIAGNOSTIC CHECKS SHOULD BE REQUIRED.
IF OVERFILLING IS NOT THE PROBLEM, GO TO COOLANT LOSS ON CHART.
NOTICE: ANYTIME COOLING SYSTEM IS OBVIOUSLY CONTAMINATED, THE SYSTEM SHOULD BE
DRAINED AND FLUSHED.
CAUTION — THE COOLING SYSTEM IS DESIGNED TO OPERATE AT 15 P.S.I. PRESSURE & TEMPERATURES
EXCEEDING 20O 5 F. CAUTION SHOULD BE EXERCISED WHEN REMOVING PRESSURE CAP OR
SERVICING THE SYSTEM.
G20001-6B
Figure 4 Cooling System Diagnosis Chart (1 of 3)