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

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2018 CX-5 Sport
Actually, CD is a turn-off to me.
Complication for nothing significant.
I am glad that the Skyactiv-G-turbo does not have CD.
Anything big issue with the G-turbo?
That is what I would like to know if any.
Since I buy for long term I wouldn't get a car with a turbo, I had a car with one years ago and it ended up leaking oil into the combustion chamber. I took a chance with the CD. I am hoping that the CD issue isn't widespread. I have given my car the beans, and I have driven it 80mph without issue so I know my valve lifter isn't missing thus far.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Since I buy for long term I wouldn't get a car with a turbo, I had a car with one years ago and it ended up leaking oil into the combustion chamber. I took a chance with the CD. I am hoping that the CD issue isn't widespread. I have given my car the beans, and I have driven it 80mph without issue so I know my valve lifter isn't missing thus far.
I'm the opposite. I'd choose turbo over cylinder deactivation anytime if I have to choose one between two devils. Turbo's reliability has been improving, and has significant benefit of boosting more power with smaller displacement. On the other hand, cylinder deactivation has minimum fuel savings in limited driving conditions, but carries much of the bad reputation from its history.

Of course in reality I'd choose neither and my current CX-5 should be my first and last Mazda unless Mazda comes up with something different. No, not interested on SkyActiv-X as SPCCI is too complicated with added spark ignition and super charger.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
When there are enough complaints about endangered driving on NTHSA website,
NTHSA will open an investigation, which might lead to a recall.
Or, Mazda could issue a safety recall voluntarily. We will see about that.
Yes. OP should go to NHTSA web site and file a safety complain against 2018 and newer MY Mazda CX-5. This's more effective than posting story here to get Mazda attention and may get forced by NHTSA to start a safety recall campaign for this cylinder deactivation problem.
 

madar

Contributor
:
2016.5 CX 5 Touring AWD, 2015 SCION XB
Thanks OP for your story. Sounds like another car manufacturer with a failed attempt with CD. Yrwei52, I always shared your opinions with this nonsense, now it looks like it has come to light. Also agree with you on the engine swap, one bad part replacing another...Why should the OP trust the newer engine when they haven't long-term tested the fix?
 
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2018 CX-9 Sig
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2014 CX-5 GT
Thanks OP for your story. Sounds like another car manufacturer with a failed attempt with CD. Yrwei52, I always shared your opinions with this nonsense, now it looks like it has come to light. Also agree with you on the engine swap, one bad part replacing another...Why should the OP trust the newer engine when they haven't long-term tested the fix?
Again, we are talking about 1-2 reports that may be linked to a faulty PCM. I would not say it has been a failure because of two posts on a forum.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Thanks OP for your story. Sounds like another car manufacturer with a failed attempt with CD. Yrwei52, I always shared your opinions with this nonsense, now it looks like it has come to light. Also agree with you on the engine swap, one bad part replacing another...Why should the OP trust the newer engine when they haven't long-term tested the fix?
IMO this problem of Mazda's cylinder deactivation is caused by bad design on hydraulic lash adjuster or hydraulic lifter. Mazda's CD relies on oil pressure to control a lock pin inside of PLA changing the functional phase between normal action pushing the valve down via the rocket arm, and no-action for CD to keep the valve closed. It's crucial on oil pressure but the oil pressure would vary sometime in wide range and depends on many variables such as oil viscosity and temperature. The PCM firmware has to make decision on oil pressure range and provide proper control signal making the PLA to change phases. This creates difficulties as oil pressure varies too much in real time due to too many factors and the software which decides different functions on PLA based on oil pressure range would be very hard to define. Mazda told OP the oil pressure is setting too low by PCM software which collapsed the PLA too much causing the rocket arm fallen off the position. Now Mazda claimed they have updated the PCM firmware to raise the oil pressure, but it could make PLA NOT collapse enough causing different problem on opposite side for CD. To me this's a catch-22 situation, all started with a bad design on PLA function for cylinder deactivation.

I also don't buy Mazda's story that one of the suppliers provided wrong PCM. When chip (EPROM) manufactures produce the PCM, they can't design the software, but only burn the code provided by Mazda into the EPROM. Either Mazda gave the wrong version of the software to the EPROM manufacture, or somehow Mazda installed older or wrong PCM which shouldn't be used due to the software updates. In any case it's definitely a major screw-up by Mazda itself, can't blame it on suppliers.
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
This sounds like something Mango would come up with to discredit Mazda.
Who's Mango? Just curious.

Of course in reality I'd choose neither and my current CX-5 should be my first and last Mazda unless Mazda comes up with something different. No, not interested on SkyActiv-X as SPCCI is too complicated with added spark ignition and super charger.
Maybe you'd be happier in this. Excellent powertrain as long as you take care of it, little to no maintenance required.



:p

Again, we are talking about 1-2 reports that may be linked to a faulty PCM. I would not say it has been a failure because of two posts on a forum.
According to the OP's dealership, his exact issue was reported and logged by Mazda at least 26 times so far. I wouldn't call it a failure either, but it definitely seems to be something worth investigating.

Mazda should do a voluntary recall to avoid expensive future engine replacements, especially if all that's required to prevent this is a reflash. IMO, the recall should involve a reflash, followed by a road test designed to recreate the limp mode scenario caused by the rocker arm. If limp mode still occurs, engine inspection and subsequent replacement should occur. If not, the issue could be considered resolved. Of course (like ceric said earlier), for this recall to occur, the number of issues needs to increase to indicate that there is a widespread issue, or (unfortunately) a failure causing injury or death would need to happen before Mazda takes action.

I would encourage any Gen2 CX-5 owners with Cylinder Deactivation to proactively address this issue with your dealership, referencing the Service Alert t.suv posted earlier:
https://static.nhtsa.gov/odi/tsbs/2019/MC-10159203-0001.pdf
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Again, we are talking about 1-2 reports that may be linked to a faulty PCM. I would not say it has been a failure because of two posts on a forum.
Have you seen Mazda's service alert from NHTSA posted above? (uhm)
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Maybe you'd be happier in this. Excellent powertrain as long as you take care of it, little to no maintenance required.



:p
Don't want to go back to Stone Age, but we also have to be careful on new technologies. Not just me, a lot of people dislike turbo due to reliability concerns. At least to me I'd have additional components with turbo to worry about when the car is aged, as I usually keep my vehicles as long as I can.

Not like turbo which we can see its great benefit, I simply can"t see enough benefit to implement cylinder deactivation which has long history of problems. SkyActiv-G is indeed a great engine, but NOT with newly added cylinder deactivation!

SlyActiv-X is based on HCCI which has never been put in production successfully although many had tried. Mazda also has to add spark ignition and super charger, hence no longer a true HCCI but a SPCCI, which is getting much more complicated. Don't want to be a guinea pig for Mazda.

BTW, don't you think "as long as you take care of it" and "little to no maintenance required" these two phrases actually contradict themselves? ;)
 

7eregrine

The man, the myth, the legend
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Land of Cleve
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2016.5 CX5
I can give credit where it's due. You DID call this one, Yrwie.
Even if it's NOT a huge deal and only effects a tiny fraction of those cars... it's clearly still an issue.
 

ColoradoDriver

Gen-1 Kodo Design
Contributor
:
Denver, CO
:
2014 CX-5 Touring
BTW, don't you think "as long as you take care of it" and "little to no maintenance required" these two phrases actually contradict themselves? ;)
No. You take care of it by doing the easy maintenance. ;)
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
BTW, don't you think "as long as you take care of it" and "little to no maintenance required" these two phrases actually contradict themselves? ;)
I'm just busting your balls, lol. But what I meant with those two phrases, "as long as you take care of it" = maintaining a decent diet for good health and to avoid obesity. If you do that, then no maintenance required (exercise, medication, etc.).
 

brillo54

Resident Curmudgeon
Contributor
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NE Indiana
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'16 CX-5 GT FWD
Of course in reality I'd choose neither and my current CX-5 should be my first and last Mazda unless Mazda comes up with something different.

C'mon man. You've said elsewhere that you got a new Toyota Yaris and we know that's a Mazda 2 with a Toyota snout and badges, so you're just in the closet when it comes to Mazda.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
I'm just busting your balls, lol. But what I meant with those two phrases, "as long as you take care of it" = maintaining a decent diet for good health and to avoid obesity. If you do that, then no maintenance required (exercise, medication, etc.).
Great explanation I have to say.

The truth is Mazda engines require more frequent maintenance at least comparing to Toyota's. Toyota has to put some special limitation for its free 2-year maintenance on Yaris / Mazda2 as Toyota engines have 10,000-mile or 12-month oil change interval, but Mazda's have 7,500-mile or 6-month OCI. So Toyota basically give 2 free oil changes for all its vehicles in 2 years. But when I asked Toyota dealer that does my Yaris get 4 free oil changes due to the much shorter 6-month oil change interval, the reply was no, only 3 times maximum which is only for Yaris.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
C'mon man. You've said elsewhere that you got a new Toyota Yaris and we know that's a Mazda 2 with a Toyota snout and badges, so you're just in the closet when it comes to Mazda.
Yes, I bought a 2018 Toyota Yaris / Mazda2 recently after I gave up on a 2018 CX-5 with cylinder deactivation. But Yaris has neither turbo nor CD which fits my requirement. It's a great little car with 39 mpg combined driving in the Nor-Cal traffic which definitely helps on gas money as it now costs $3.89 per gallon at the nearby Costco! The 6-speed SkyActiv-Drive transmission is a rare-find for a small 1.5L engine and so far I like this Yaris a lot. I hope Mazda can go to the basics and don't get hung up too much on new technology or try to be the first to overcome a design which apparently is not easy to be a successful and reliable product.
 
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2018 CX-5 Sport
I'm not totally believing the cause that Mazda said because the Service Alert says to check for debris and does not mention changing the PCM programming. And the debris looks like grease or goop. Maybe the oil valves were accidentally installed with latex sealant, idk. I guess I have to believe what Mazda says though. I will bring the Service Alert to my dealer when I go to buy another filter and ask him if they have had any reports of this. Meanwhile I will drive it like I have been, it does run great.
 
Yes. OP should go to NHTSA web site and file a safety complain against 2018 and newer MY Mazda CX-5. This's more effective than posting story here to get Mazda attention and may get forced by NHTSA to start a safety recall campaign for this cylinder deactivation problem.
I just did this. Hopefully this will pick up some traction.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
I'm not totally believing the cause that Mazda said because the Service Alert says to check for debris and does not mention changing the PCM programming. *
Like I said in my earlier post, I also believe Mazda can't blame the PCM software only because the the problem is coming from the bad design. I simply don't think this problem can easily be fixed by software updates in PCM, just like EPB dragging issue.
 
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I'm not totally believing the cause that Mazda said because the Service Alert says to check for debris and does not mention changing the PCM programming. And the debris looks like grease or goop. Maybe the oil valves were accidentally installed with latex sealant, idk. I guess I have to believe what Mazda says though. I will bring the Service Alert to my dealer when I go to buy another filter and ask him if they have had any reports of this. Meanwhile I will drive it like I have been, it does run great.
MyFirstMazda you may be right on this. It could be the reason Mazda refuses to reflash all new vehicles on the lot. They may not be sure what is truly the cause. Remember, all of this happened to me back in October and this problem was still in its infancy. Maybe since then they have discovered other issues that may be contributing to this. Good Call.
 
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