Mazda CX-30 2018–2021 — technical service bulletin
Bulletin 01-002-21-3767a · NHTSA communication 10191534 · issued Apr 30, 2021
Technical service bulletin
communication type
Engine and Engine Cooling
component
2018–2021
model years
13
vehicle entries
Official 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. To eliminate this concern, the switchable HLA has been modified for increased oil supply to reduce air bubbles in the oil passage. NOTE: The switchable HLA can be pressed down with a finger if air bubbles have accumulated in it.
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.