Subaru Impreza 2012–2013 — technical service bulletin
Bulletin 02-146-13 · NHTSA communication 10093305 · issued Oct 7, 2013
Technical service bulletin
communication type
Engine
component
2012–2013
model years
3
vehicle entries
Official summary
"this bulletin announces the availability of revised valve train components developed to reduce a tapping sound which may be heard coming from the left-hand (b2) side of the engine when the engine is warm. This bulletin does not address any cold engine or start-up sounds. The changes consist of: design change to the valve rockers camshaft profile change increased intake valve stem length (1.65mm longer intake, 2.4mm longer exhaust) in addition, the insulator pad has been eliminated from the b2 intake manifold protector."
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.