Mazda CX-5 2018–2020 — technical service bulletin
Bulletin SA-012-19b · NHTSA communication 10168140 · issued Nov 22, 2019
Technical service bulletin
communication type
Engine and Engine Cooling
component
2018–2020
model years
4
vehicle entries
Official summary
A valve tapping or knocking noise may be heard from the top end after the engine cools down (the vehicle is parked overnight) or after it has been idling for an extended time. The tapping noise will decreases as the vehicle is being driven or if the rpm is held above 2500-3000 RPM. This may be caused by the valve Hydraulic Lifters (HLA) bleeding down as the engine cools or when the engine has been idling for an extended period of time, creating excessive valve lash clearance.
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.