How to Quiet That Annoying Subaru Engine Sound

This bulletin applies to 2011 Subaru Forester models equipped with a 2.5L naturally aspirated engine. When diagnosing an engine for an unusual sound and it has been determined to be coming from the left side cylinder head area, the head, intake camshaft, intake valves and rocker arm, pivots may need to be replaced.

Information courtesy of Mitchell 1

Mike Mavrigian

Sept. 11, 2022

The sound can be heard at idle and increases with RPM, similar to the sound of a sewing machine.

This sound is created by the contact of the pivot and rocker arm when the intake valve is approaching its seat. As a counter measure, a modified cylinder head, intake camshaft, intake valves and rocker arm pivots were incorporated into production Jan. 21, 2011 - starting with engine number 0055031.

All of the intake and exhaust rocker arm pivots on the left side must be replaced with the new rocker arm pivot part number. Failure to replace both intake and exhaust pivots with the new part number will result in camshaft bind and/or insufficient valve clearance.

PART QTY NEW P/N OLD P/N

Head assembly, LH…….1…………..11063AB652…………11063AB650

Camshaft, INT, LH…….1…………...13037AA802…………13037AA801

Valve, INT……………...4…………...13201AA620…………13201AA570

Pivot, rocker arm……...8……………13296AA051…………13296AA040

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

Mike Mavrigian

Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.