SA-025-20a

Mazda North American Operations
Irvine, CA 92618-2922
Service Alert
Subject:
VALVE TAPPING OR KNOCKING NOISE HEARD FROM CYLINDER
HEAD
Service Alert No.: SA-025/20
Last Issued: 03/27/2020
BULLETIN NOTES
This service alert supersedes the previously issued service alert listed below. The changes are noted in
Red text.
Previous Service Alert:
Date(s) Issued:
SA-025/20
02/11/20
SA-012/19
11/22/2019, 08/06/19 and04/01/19
APPLICABLE MODEL(S)/VINS
2018-2019 CX-5 vehicles (2.5L with cylinder deactivation)
2018-2019 Mazda6 vehicles (2.5L with cylinder deactivation)
DESCRIPTION
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.
Click here for an example of the noise.
REPAIR PROCEDURE
1. Verify customer concern and verify the tapping sound is coming from the cylinder head.
NOTE: If the symptom cannot be reproduced, allowing the vehicle to sit overnight and inspect it in the
morning.
Page 1 of 2
CONSUMER NOTICE: The information and instructions in this bulletin are intended for use by skilled technicians. Mazda technicians utilize the proper tools/
equipment and take training to correctly and safely maintain Mazda vehicles. These instructions should not be performed by “do-it-yourselfers.” Customers
should not assume this bulletin applies to their vehicle or that their vehicle will develop the described concern. To determine if the information applies,
customers should contact their nearest authorized Mazda dealership. Mazda North American Operations reserves the right to alter the specifications and
contents of this bulletin without obligation or advance notice. All rights reserved. No part of this bulletin may be reproduced in any form or by any means,
electronic or mechanical---including photocopying and recording and the use of any kind of information storage and retrieval system ---without permission in
writing.
© 2020 Mazda North American Operations, U.S.A.
03/30/2020 10:12 AM tlawrenc
Service Alert No.: SA-025/20
Last Issued: 03/27/2020
Can the tapping or knocking sound be reproduced?


Yes: Go to step 2.
No: Interview the customer when they experienced the condition and try to reproduce the
conditions. If unable to reproduce the tapping sound, this SA does not apply.
2. Perform HLA bleeding procedure.NOTE: If the vehicle has returned after performing the HLA bleeding
procedure, go to step 3.a. Verify oil is at the correct level and in good condition.
NOTE: If service is almost due, change the engine oil and filter and then proceed to next step.
b. Hold the engine rpm between 2500-3000 for 5 min, then idle for 5 min. Repeat this 2 times.
Does the top end tapping noise continue?


Yes: Go to step 3.
No: Repair completed.
3. Before performing repair work, record a video of the engine being started and the tapping noise.
4. Contact Hotline for further instructions.
NOTE: Make sure to attach the video to the Hotline file.
WARRANTY INFORMATION
Normal Warranty applies.
Page 2 of 2
CONSUMER NOTICE: The information and instructions in this bulletin are intended for use by skilled technicians. Mazda technicians utilize the proper tools/
equipment and take training to correctly and safely maintain Mazda vehicles. These instructions should not be performed by “do-it-yourselfers.” Customers
should not assume this bulletin applies to their vehicle or that their vehicle will develop the described concern. To determine if the information applies,
customers should contact their nearest authorized Mazda dealership. Mazda North American Operations reserves the right to alter the specifications and
contents of this bulletin without obligation or advance notice. All rights reserved. No part of this bulletin may be reproduced in any form or by any means,
electronic or mechanical---including photocopying and recording and the use of any kind of information storage and retrieval system ---without permission in
writing.
© 2020 Mazda North American Operations, U.S.A.
03/30/2020 10:12 AM tlawrenc