HEATER DOES NOT PROVIDE HEAT DURING EXTENDED IDLE. Saturn Saturn 1991

For 1990-2009 cars

# HEATER DOES NOT PROVIDE HEAT DURING EXTENDED IDLE

#### SUBJECT HEATER DOES NOT PROVIDE HEAT DURING EXTENDED IDLE AFTER START-UP IN COLD WEATHER (-12 DEGREES C (+10 DEGREES F) (EXPLAIN RECOMMENDED HEATER OPERATION)).

#### MODELS AFFECTED 1991-1995 SATURNS

#### CONDITION:

CUSTOMERS MAY COMMENT ABOUT COOL AIR FLOWING FROM THE HEATER DURING EXTENDED IDLE AFTER A START-UP IN COLD WEATHER OF -12 DEGREES C (+10 DEGREES F).

#### IMPORTANT: THE TEMPERATURE LISTED IN THIS BULLETIN SUPERSEDES THE TEMPERATURE LISTED IN THE OWNER'S MANUAL. THIS NEW TEMPERATURE OF -12 DEGREES C (+10 DEGREE F) WILL APPEAR IN THE 1996 OWNER'S MANUAL.

#### CAUSE:

DURING COLD WEATHER CONDITIONS OF -12 DEGREES C (+10 DEGREES F) OR COLDER, ENGINE COOLANT TEMPERATURE DECREASES QUICKLY WHEN IDLING WITH THE HEATER FAN ON HIGH-SPEED. THIS IS DUE TO THE HEATER FAN HELPING TO COOL THE ENGINE COOLANT AS IT FLOWS THROUGH THE HEATER CORE.

#### CORRECTION:

RECOMMEND TO THE CUSTOMER THAT THE HEATER FAN BE SET AT A LOWER SPEED POSITION (FAN SPEED I OR II) UNTIL THE ENGINE IS WARMED-UP AND BEING DRIVEN. AFTER THE ENGINE IS WARMED-UP AND IS BEING DRIVEN, THE HEATER FAN CAN BE SET TO A HIGHER SPEED POSITION.

#### IMPORTANT: REPLACING THE THERMOSTAT WITH ANOTHER THERMOSTAT WILL NOT INCREASE THE AMOUNT OF HEAT AVAILABLE FROM THE HEATER. IF THE THERMOSTAT IN THE ENGINE IS SUSPECTED, IT SHOULD BE CHECK, USING THE SERVICE PROCEDURES IN THE "1991-1994 ENGINE MECHANICAL SERVICE MANUAL" OR THE "1995 ENGINE/FUEL/AIR INTAKE/EXHAUST SERVICE MANUAL" (DEPENDING ON MODEL YEAR OF VEHICLE).

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SATURN BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO PROVIDE INFORMATION THAT COULD ASSIST IN THE PROPER SERVICE OF A VEHICLE. PROPERLY TRAINED TECHNICIANS HAVE THE EQUIPMENT, TOOLS, SAFETY INSTRUCTIONS AND KNOW-HOW TO DO A JOB PROPERLY AND SAFELY. IF A CONDITION IS DESCRIBED, DO NOT ASSUME THAT THE BULLETIN APPLIES TO YOUR VEHICLE, OR THAT YOUR VEHICLE WILL HAVE THAT CONDITION. SEE A SATURN RETAILER FOR INFORMATION ON WHETHER YOUR VEHICLE MAY BENEFIT FROM THE INFORMATION.

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