Topaz L4-140 2.3L HSC (1984)
Heater Hose: Customer Interest
Heater Core - Intermittent Moaning Noise
Article No. 84-18-11
HEATER CORE MOAN - INTERMITTENT
FORD 1984 TEMPO WITH 2.3L ENGINE ONLY
LINCOLN-MERCURY 1984 TOPAZ WITH 2.3L ENGINE ONLY
On some vehicles, a moan sound may emanate from the heater core when the engine is operating between 2500 and 3500 rpm. The moan sound may be
fluid flow induced vibration in the heater core. To verify the condition, perform the following diagnostic test and install a restrictor in the heater inlet
hose, if required. This service procedure is applicable only to 2.3L engine vehicles and not on the 2.0L Diesel engine units.
Diagnostic Test Procedure
1.
Start the engine and run up in Park to approximately 3500 rpm to verify the heater core moan condition.
2.
If a heater core moan sound occurs, stop the coolant flow by clamping the heater core inlet hose with a "C" clamp or locking pliers applied with
protective pads.
a.
If the heater core moan sound does not stop after stopping the coolant flow, refer to the Noise Vibration and Harshness (NVH) Diagnosis
located in the 1984 Car Shop Manual.
b.
If the moan sound is stopped by clamping the heater inlet hose, stop the engine, remove the clamp and proceed to Step #3.
3.
Install a water flow restrictor in the heater core inlet hose as outlined in the Water Flow Restrictor Installation Procedure.
Water Flow Restrictor Installation Procedure
1.
Loosen the radiator pressure cap.
2.
Loosen the heater inlet hose clamp at the heater core tube and disconnect the hose from the heater core tube.
