Cylinder Deactivation Update

[mazdadude]

Thanks for your feedback. I would say let's put this CD behind us and let's just enjoy the car the way it meant to was intended.

I just picked up a 2020 with Polymetal Grey colour today. One weird thing I noticed was that under moderate breaking from high speed (let's say 70mph to 10mph) I noticed the rear breaks are making this "mild rumbling noise". Sounded like touk, touk, touk...as in, the ABS system is constantly kicking in even under mild breaking.

I found a section in the manual which reads "this vehicle has a power-assisted brakes that assist automatically though normal use" - could that be it?

Any ideas idea? Car is only has 60 miles on it, so maybe it needs time to break in?

As the manual suggests, like the engine and transmission, the brakes are to be bedded in/broken in gently for the first 600 miles. Avoiding hard stopping unless absolutely necessary. I would give your brand new car some time to break in. Check your tire PSI to get a start point.

 

[dougal]

Does the Mazda3 Turbo Hatch have CD?

No. The 2.5T engine does not have CD.

 

[Dark5tar]

As the manual suggests, like the engine and transmission, the brakes are to be bedded in/broken in gently for the first 600 miles. Avoiding hard stopping unless absolutely necessary. I would give your brand new car some time to break in. Check your tire PSI to get a start point.

After 500 miles the brake noise has completely disappeared. Must be the pads and rotors breaking in.

 

[kdaug]

I spoke to my Mazda service advisor the other day about the TSB # 01-006/20 and the Service Alert #SA-012/19 re the noisy H.L.A.'s which I had printed out and showed to him. He then looked them up on his computer and advised me that, unless I was hearing what would be easily discernable noisy HLA's they wouldn't even consider carrying out either of the required service/repair procedure. Having said that I did say that I hadn't heard what I thought are noisy HLA's as of yet. I guess what I will do is ask them, at every future service, to listen for any potential noise from the lifters.

Now, I have yet to hear any noisy HLA's on initial startup, but I keep my vehicle in a garage so it never gets very cold during the winter, and, I rarely idle it for very long, so may be that would make it more unlikely that the noise might arise.

 

[Thejas]

Just so you guys know with regards to the CD "feature". Mazda released a new service alert for the 2.5 with CD. They have been replacing the cylinder head(with new modified one) in cars that have failures due to CD. This was released after the recall and is a fairly recent development. Obviously there's been troubles even after the recall

I imagine something has to happen for me to get this done? It's not a real recall correct?

 

[yrwei52]

I imagine something has to happen for me to get this done? It's not a real recall correct?

If you’re referring to this Service Alert, it’s nothing to do with previous recall 、Service Alerts and TSBs related to cylinder deactivation. It only gives Mazda dealers a new part number 0000-99-SCX5 for ordering pre-assembled cylinder head set kit when there’s a need for all 2.5L’s with cylinder deactivation.

Service Alert No.: SA-058/20 - NEW CYLINDER HEAD ASSEMBLY ESTABLISHED

If your 2.5L with cylinder deactivation is having metal-to-metal ticking noise from valve clearance, then you may need to do something about the hydraulic lash adjusters (HLA):

Service Alert No.: SA-012/19 Last Issued: 11/22/2019 - VALVE TAPPING OR KNOCKING NOISE HEARD FROM CYLINDER HEAD

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.

TSB No.: 01-006/20 Last Issued: 11/04/2020 - TAPPING NOISE FROM ENGINE

APPLICABLE MODEL(S)/VINS
2019-2020 Mazda3 (US spec)
2018-2020 Mazda6 (US spec)
2018-2020 CX-5 (US spec)

DESCRIPTION
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.

 

[Thejas]

If you’re referring to this Service Alert, it’s nothing to do with previous recall 、Service Alerts and TSBs related to cylinder deactivation. It only gives Mazda dealers a new part number 0000-99-SCX5 for ordering pre-assembled cylinder head set kit when there’s a need for all 2.5L’s with cylinder deactivation.

Service Alert No.: SA-058/20 - NEW CYLINDER HEAD ASSEMBLY ESTABLISHED

If your 2.5L with cylinder deactivation is having metal-to-metal ticking noise from valve clearance, then you may need to do something about the hydraulic lash adjusters (HLA):

Service Alert No.: SA-012/19 Last Issued: 11/22/2019 - VALVE TAPPING OR KNOCKING NOISE HEARD FROM CYLINDER HEAD


TSB No.: 01-006/20 Last Issued: 11/04/2020 - TAPPING NOISE FROM ENGINE

They actually replaced my hlas under warranty and I got car back recently. Now I have to figure this out https://www.mazdas247.com/forum/index.php?threads/transmission-issues-loss-of-power.123875201/. Also need to find out if my rocker arm is there and if they did the pcm update for it.

 

[yrwei52]

They actually replaced my hlas under warranty and I got car back recently. Now I have to figure this out https://www.mazdas247.com/forum/index.php?threads/transmission-issues-loss-of-power.123875201/.

That’s unfortunate!

Also need to find out if my rocker arm is there and if they did the pcm update for it.

Yes, the cylinder deactivation recall by Mazda doesn’t include ANY verification of fallen rocker arms. And it’s unfortunate that there’s no symptons of fallen rocker arms until you need engine power the most and put you in very dangerous situation!

Dangerous cylinder deactivation trouble on 2018 CX-5 and 6 models

NHTSA Recall Campaign No.: 19V-497-000

It behooves everyone with a 2018/19 2.5NA to put it in manual and wind it out to 5k and keep it there for a minute, whether it's had the fix or not.

What are you waiting for?

No, not literally a minute. Just a few seconds, Maybe between 5-15 seconds. Remember, all you are trying to do is see if the computer senses a *misfire* on a cylinder due to the air/fuel ratio not being correct. So it may sense it as soon as you get above 5500 rpms or it may take it a few seconds to sense it. Mine happened when I was passing a vehicle. I was accelerating and keeping the RPMs high when it would go to limp mode.

 

[Dark5tar]

Guys, the reasons we all worry about CD is long term longevity and reliability.

Let's all post our mileages driven on our Mazda's with CD and see if anyone has experienced any issues with CD.

I'll start. Mine is a 2020 CX5 2.5L with CD. It's presumed mine already has the software fixed installed from factory and currently done 10k miles with no issues. I never felt CD during city or highway driving.