Town Car V8-4.6L VIN W (1997)
Heater Core: Testing and Inspection
HEATER CORE
WARNING: CARBON MONOXIDE IS COLORLESS, ODORLESS AND DANGEROUS. IF IT IS NECESSARY TO OPERATE THE
ENGINE WITH THE VEHICLE IN A CLOSED AREA SUCH AS A GARAGE, ALWAYS USE AN EXHAUST COLLECTOR TO
VENT THE EXHAUST GASES OUTSIDE THE CLOSED AREA.
The heater core is an all-aluminum core which has two rows of flat tubes to maximize engine coolant flow. It is located in the A/C evaporator
housing in the passenger compartment under the instrument panel.
1. Inspect for visible evidence of coolant leakage at the heater water hose to heater core attachments. A coolant leak at the heater water hose
could follow the heater core tube to the heater core and appear as a leak in the heater core.
NOTE: Testing of returned heater cores reveals that a large percentage of heater cores are good and should not have been replaced. If a heater
core leak is suspected, it should be tested in the Plugged Heater Core procedures before removing the heater core. Perform a system inspection
by checking the heater system thoroughly as follows:
2. Check the system for loose or overtightened heater water hose clamps. The clamps should be tightened to 1.7-2.4 N.m (15-21 lb-in).
3. If leakage is found and the heater water hose clamps are over-tightened, replace the clamp and tighten to the proper level. An over-tightened
clamp can cause leakage at the heater water hose connection and damage the heater core tube.
PLUGGED HEATER CORE
Check to see that the engine coolant is at the proper level. Start the engine and turn on the heater. When the engine coolant reaches operating
temperature, feel the heater core outlet hose to see if it is hot. If it is not hot, the heater core may have an air pocket or may be plugged, or the
thermostat is not working properly.
