Heater - Poor Performance

91ford04

Article No. 91-3-7


^ HEATER - LACK OF HEAT - THERMOSTAT JACKET CLOGGED - 1.8L ENGINE
^ COOLING SYSTEM - THERMOSTAT JACKET CLOGGED - 1.8L ENGINE


FORD: 1991 ESCORT


LINCOLN-MERCURY: 1991 TRACER


ISSUE: Poor heater performance may be caused by restricted engine coolant flow. This condition may be caused by a piece of casting flash that is attached to the water jacket inside the cylinder head. The casting flash restricts coolant flow through the heater pipe inlet next to the thermostat jacket.

ACTION: Inspect the thermostat jacket and remove any casting flash. Refer to the following procedure for service details.


NOTE: THE ENGINE TEMPERATURE WILL OPERATE IN THE NORMAL RANGE WITH OR WITHOUT THE CASTING FLASH.

1. Drain the cooling system.

2. Remove the thermostat housing and thermostat. Refer to the 1991 Escort/Tracer Shop Manual, Page 03-03-25, for removal procedure.

Figure 1:

3. Visibly check and confirm by feeling with your finger for any piece of casting flash attached to the heater pipe inlet beside the thermostat jacket, Figure 1.


4. Remove any casting flash from the thermostat jacket.


5. Re-install the thermostat and thermostat housing. Refer to the 1991 Escort/Tracer Shop Manual, Page 03-03-23, for installation procedure.


NOTE: USE A NEW THERMOSTAT GASKET (FO2Z-8255-A).

6. Refill the cooling system.

7. Check the heater performance.

PART NUMBER PART NAME CLASS

F02Z-8255-A Thermostat Gasket BG

OTHER APPLICABLE ARTICLES: None


WARRANTY STATUS: Eligible Under Basic Warranty Coverage

OPERATION DESCRIPTION TIME

910307A Remove Flashing 0.6 Hr.

DEALER CODING

BASIC PART NO. CONDITION CODE
8255 49

OASIS CODES: 208000, 208100, 402000