CX-5 Tapping noise

[Jack Rabbit]

Ok. Engine has been making noise for some time now. Indy mechanic last year said its just injectors. Took to dealer last year to have whole car checked out and said check the engine for any problems, especially cracked cylinder head. Vocally mentioned the sound and was told it's the injectors. They had the vehicle and heard it running.

I usually jump in my car and startup and then drive.

So today, while checking the brakes, left vehicle idling to go get my wheelchocks, and heard this from 60 feet away.

Sure sounds like the valves to me.

Also if you listen you can hear both the injectors clicking but you can also hear the tapping noise.

And it hasn't thrown any engine related codes.

Any opinions?
Lifters, HLA's or injectors ???
Thanks.

 

[macker]

IMO, revving the engine to get rid of bubbles is only a temporary solution. That’s why Mazda came out the second TSB replacing switchable HLAs for the tapping noise. I can tell you the noise will come back at certain point. Keep us posted.

I believe the whole issue of this tapping noise started from the reprogramming of the oil pressure feeding to those SHLAs from the safety recall where Mazda was trying to resolve the fallen rocker arm problem on 2.5L NA with cylinder deactivation. The change of oil pressure definitely affected the original SHLAs causing bubbles, and it could be something even the newer version SHLAs can’t be functioning properly sometimes.

My biggest concern is the impact this may have on the longevity of the engine. Is the oil getting to all the critical parts in the top end of the engine when it needs to, i.e. startup? Is it possible when you're running less than half the oil capacity in the pan that it affects the oil pressure, which in turn causes the top end to get noisy? Lots of questions I don't have answers for...

This is the 1st Mazda I've owned and sadly, despite the nice drive and features, it may be my last. In fact, I may sell it now, while prices are still good in the resale market.

I will be keeping my eye (and ears) on this and keep the forum updated.

 

[macker]

Did you ever try the bleeding (rev) procedure prior to doing the oil change.

I didn't, though my post oil change procedure, I added a longer than normal revving cycle. IF the tapping returns, I will give it a shot and report.