Affected Component: ENGINE AND ENGINE COOLING

Date Published
JAN 14, 2021
NHTSA TSB #
10186695
TSB Document
Summary
Some vehicle may exhibit a tapping noise from the engine during idling; etc., and synchronized to the engine rpm. The tapping noise may be caused by the switchable hydraulic lash adjuster (HLA), which may not work properly due to air bubbles accumulated in the oil passage in it.