Thermactor - Moaning Noise From Engine Compartment

89ford21

NOISE-"MOANING"-FROM ENGINE COMPARTMENT- 5.8L-VEHICLES OVER 8500 GVW BUILT BEFORE 1/30/89

THERMACTOR-"MOANING" NOISE FROM ENGINE COMPARTMENT-5.8L-VEHICLES OVER 8500 GVW BUILT BEFORE 1/30/89

Article No. 89-14-18

LIGHT TRUCK: 1988-89 E-250, E-350, F-250, F-350

ISSUE: A "moaning" noise may be heard coming from the engine compartment while driving. The "moaning" usually occurs in drive modes between 1800-2000 RPM. The thermactor air pump output pulses react with the engine firing pulses, as both the water pump and air pump have identical drive ratios. This creates the moaning sound.

ACTION: Install a new thermactor air pump pulley. Refer to the following procedure for service details.

ECONOLINE

1. Check to see if the moaning condition exists in drive modes between 1800-2000 RPM. If condition exists, proceed to step 2.

Figure 1:

2. Remove and throw away the existing thermactor air pump pulley.

3. Install a new thermactor air pump pulley, Figure
1. Refer to the 1988/1989 Truck Shop Manual, Page 21-21-42 for bolt torque limits and Section 27-08 for accessory drive belt service details.

Figure 2:

F-Series

1. Check to see if the moaning condition exists in the drive modes between 1800-2000 RPM. If the condition exists, proceed to Step 2.

2. Remove and throw away the existing thermactor air pump pulley.

3. Install a new thermactor air pump pulley, Figure
1. Refer to the 1988/1989 Truck Shop Manual, Page 21-21-42 for bolt torque limits and Section 27-08 for accessory drive belt service details.

4. Remove and throw away the existing thermactor silencer and bracket assembly.

5. Install a new silencer and bracket assembly, Figure 2.

6. Install a new exhaust air supply muffler hose, Figure 2.




Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

PART NUMBER PART NAME CLASS

E9TZ-9B447-A Air Pump Pulley B
E9TZ-9H467-A Silencer & Bracket Assy. C
E8TZ-9F451-B Hose - Exhaust Air Supply C
Muffler

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage, Emissions Warranty Coverage

OPERATION DESCRIPTION TIME
891418A Econoline 0.5 Hr.
891418A F-Series 0.5 Hr.

DEALER CODING
BASIC PART NO. CONDITION CODE
9C480 56
OASIS CODES: 4400, 7113