Heater Core - Intermittent Moaning Noise
84ford8Article 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.
FIGURE 8:
3. Insert the water flow restrictor (Part No. E43Z- 18D358-A) into the end of the heater inlet hose so a minimum hose end-to-restrictor clearance of 1-1/2 inches is provided (Figure 8).
4. Reinstall the inlet heater hose on the inlet heater core tube and tighten the hose clamp to 16-22 in.lbs. torque.
5. Check and add coolant to the cooling system as required as outlined in Section 27-01 of the Shop Manual.
6. With the radiator pressure cap installed, operate the engine to check and correct for coolant leaks at the heater hose connections. Run vehicle long enough to discharge any air from the heater core. Make sure the engine is warm enough to open the thermostat.
PART NUMBER PART NAME CLASS
E43Z-18D358-A Restrictor CG
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP18476A84
TIME: 0.4 Hr. DLR. CODING: Basic Part No. 18358 Code: 56