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Technical Service Bulletins

TSB
96-5-17
  • ENGINE – 4.9L/5.0L/5.8L – “HOOTING” NOISE FROM ENGINE COMPARTMENT – VEHICLES BUILT THROUGH 10/15/95
  • NOISE – “HOOTING” FROM ENGINE COMPARTMENT – VEHICLES WITH 4.9L/5.0L/5.8L ENGINE BUILT THROUGH 10/15/95
Publication Date: FEBRUARY 26, 1996

LIGHT TRUCK:
1996 BRONCO, F-150-350 SERIES

ISSUE:

A “hooting” noise can be heard coming from the engine compartment. This may be caused by the fuel vapor return tube reacting with the vapor management valve.

ACTION:

Install a revised Fuel Vapor Return Tube Assembly (F6TZ-9G271-MA). The revised tube assembly contains a resonator which lowers the noise. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

  1. Perform EEC self-test and complete repairs for any codes present following normal diagnostics found in the 1996 Powertrain Control/Emissions Diagnosis (PC/ED) Manual.
  2. The “hoot” noise will only occur when the vapor management valve is between 35-45% duty cycle. To place the vapor management valve within this duty cycle range, Engine Coolant Temperature (ECT) must be stabilized at 82.2C (180F), underhood temperature must be greater than 37.8C (100F), and the vapor management valve must be reset. The vapor management valve will then pass through the 35-45% duty cycle range within 5 minutes at engine idle.
  3. Verify the noise concern by completing the following test procedure:
    1. To stabilize ECT at 82.2C (180F) and raise underhood temperatures above 37.8C (100F), allow the vehicle to idle indoors for 15 minutes with the hood closed while monitoring ECT.
    2. When ECT has stabilized at 82.2C (180F), allow vehicle to idle an additional 15 minutes with hood closed.
    3. Place the vapor management valve within the 35-45% duty cycle range by turning the key to the off position, then restart the engine and allow to idle. The noise should be heard on the right side of the engine compartment within 5 minutes at engine idle. An increase in vapor management valve vibration should also be noticeable to the touch.
    4. If no “hoot” noise is present, proceed with normal diagnostics for engine noise concerns by attempting to isolate the source of the noise through the use of a technician’s stethoscope.
  4. To repair the “hoot” noise, disconnect the fuel vapor return hose from the vapor management valve canister and remove.
  5. Install the revised Fuel Vapor Return Tube Assembly (F6TZ-9G271-MA) being sure that the end of the hose with the resonator is attached to the vapor management valve. Route the revised hose exactly as the original (Figure 1).


    Figure 1 – Article 96-5-17


PART NUMBERPART NAME
F6TZ-9G271-MAFuel Vapor Return Hose Assembly

OTHER APPLICABLE ARTICLES:

NONE

WARRANTY STATUS:

Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATIONDESCRIPTIONTIME
960517AInstall Revised Fuel Vapor Return Tube Assembly0.4 Hr.

DEALER CODING

BASIC PART NO.CONDITION CODE
9G27156

OASIS CODES:

497000, 499000, 702000, 702100


Copyright 1996 Ford Motor Company