Engine Noise - Knocking Sound - Secondary Air Pump

Article No.
96-7-27

03/25/96

^ ENGINE NOISE - "KNOCKING" SOUND - 5.8L - SECONDARY AIR INJECTION (AIR) PUMP

^ NOISE - " KNOCKING" SOUND - 5.8L - SECONDARY AIR INJECTION (AIR) PUMP

LIGHT TRUCK:
1995-96 BRONCO, ECONOLINE, F-150-350 SERIES

ISSUE:
A "knocking" noise may occur when engine is cold and under acceleration. The noise could be coming from the Secondary Air Injection (AIR) Pump.

ACTION:
Verify the knock noise is coming from the AIR Pump and install the correct AIR Pump Service Kit for the application. Refer to the following diagnosis and service procedures for details.

DIAGNOSIS

Test drive the vehicle cold. The knock noise is most noticeable while the engine is under load at approximately 1500 rpm. The concern may be verified on automatic transmission-equipped vehicles by first setting the parking brake, and with the wheels chocked, starting the engine and placing the vehicle in gear. Verify the knock noise is coming from the AIR Pump by using a technician's stethoscope while the engine speed is approximately 1500 rpm.

SERVICE PROCEDURE

NOTE:
THE NEW AIR PUMP IS ORIENTED IN A POSITION 180 DEGREES OPPOSITE TO THE PRODUCTION AIR PUMP.

















Install the specified AIR Pump Service Kit for each application using the charts:

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

960727A Replace Air Pump And 0.8 Hr.
Hoses - Econoline

960727B Replace Air Pump And 0.7 Hr.
Hoses - F-Series, Bronco

DEALER CODING
CONDITION
BASIC PART NO. CODE
9A486 56

OASIS CODES: 702000