Cougar/XR7 V8-4.6L VIN W (1997)
Heater Core: Testing and Inspection
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
assembly 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 as described in the Plugged Heater Core procedures before removing the heater core. Perform a system
inspection by checking the heater system thoroughly.
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.
Pressure Test
Use Rotunda Radiator Pressure Tester 014-R1072 or equivalent to perform pressure test.