Intake rocker out of place on cylinder 4

[LeRiDionne]

Hi I have an intake rocker out of place (found undamaged on the bottom of the head). The star wheel has been destroyed in the process...

I don't know why the rocker went off. Any indications on repair to perform? Can I reassemble as is? Need to replace lifter or other components? I had the PCM upgrade done in 2019 for this issue.

 

[yrwei52]

As I’ve been saying many times before, fallen rocker arm on cylinder #4 from the 2.5L NA with cylinder deactivation is the hardware design issue. Mazda used a cheap way to mask the problem by adjusting the oil pressure on adjustable HLAs with a PCM update but the problem could still be happening IMO like you just found out unfortunately.

Dangerous cylinder deactivation trouble on 2018 CX-5 and Mazda6 models

Not much you can do to prevent this problem happening again 100%. You can replace the damaged parts with new HLAs, preferably on all adjustable HLAs used for cylinder deactivation, i.e. cylinder #1 and #4, and make sure your PCM is up to date.