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

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
When my car did this Mazda corporate was wanting all engines experiencing this issue sent back to Japan. So they replaced my engine. Not sure how they will handle it now. And yes, it had fallen off and was just sitting there.
I thought Mazda has figured out what happened and came up a fix on PCM software. If they need your engine to research the problem in Japan, that indicates Mazda still hasn't figurd out what's going on to your engine and many others.
 
I thought Mazda has figured out what happened and came up a fix on PCM software. If they need your engine to research the problem in Japan, that indicates Mazda still hasn't figurd out what's going on to your engine and many others.
I agree. I feel they should recall all of the vehicles that have cylinder deactivation (CX-5 and 6), reflash the PCM, and do a visual inspection to make sure the rocker is in place at least. But it has been almost 6 months since my engine was replaced and I tried for a long time to ge them to recall and still nothing has been done. I guess my voice isn*t loud enough.
 
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2019 Cx-5 sport
so I have a 2019 sport cx5 , how would I try and replicate this failure
what steps to try and follow ?

have cx5 in sport mode or normal mode ?
cruise control on ?
what speed ?
then what , just give it gas ?

just wondering , If I should be complaining to mazda about 'CD' ..
thanks
 
:
2018 CX-5 Sport
My guess is that some engines were not assembled correctly or bad parts were used, in order for a rocker to fall off. The spring tension will keep it in place. Maybe a spring broke. And it blows my mind that an engine can run with a rocker sitting under the valve cover somewhere and the valve stuck open. Did you hear any loud noise at any point come from the motor?
 
:
2018 CX-5 Sport
I agree. I feel they should recall all of the vehicles that have cylinder deactivation (CX-5 and 6), reflash the PCM, and do a visual inspection to make sure the rocker is in place at least. But it has been almost 6 months since my engine was replaced and I tried for a long time to ge them to recall and still nothing has been done. I guess my voice isn*t loud enough.
The PCM story can't be the problem. Maybe they are flashing it to disable cylinder deactivation.
 
:
2018 CX-5 Sport
so I have a 2019 sport cx5 , how would I try and replicate this failure
what steps to try and follow ?

have cx5 in sport mode or normal mode ?
cruise control on ?
what speed ?
then what , just give it gas ?

just wondering , If I should be complaining to mazda about 'CD' ..
thanks
You can't complain about CD if it hasn't failed. It sounds like he was cruising at 55 mph or so in sport mode and pushed the pedal to the floor to get it to exceed 5K rpms. So try that if you want (shrug)
 

yugrus

Contributor
:
CX-5 GT
so I have a 2019 sport cx5 , how would I try and replicate this failure
what steps to try and follow ?

have cx5 in sport mode or normal mode ?
cruise control on ?
what speed ?
then what , just give it gas ?

just wondering , If I should be complaining to mazda about 'CD' ..
thanks
My guess is that some engines were not assembled correctly or bad parts were used, in order for a rocker to fall off. The spring tension will keep it in place. Maybe a spring broke. And it blows my mind that an engine can run with a rocker sitting under the valve cover somewhere and the valve stuck open. Did you hear any loud noise at any point come from the motor?
The affected valve stays closed all the times. The second valve does all the work in this case. At low speed that's enough of air for stoichiometric ratio. At WOT the air flow is not sufficient, hence the limp mode.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
My guess is that some engines were not assembled correctly or bad parts were used, in order for a rocker to fall off. The spring tension will keep it in place. Maybe a spring broke. And it blows my mind that an engine can run with a rocker sitting under the valve cover somewhere and the valve stuck open. Did you hear any loud noise at any point come from the motor?
I agree with yugrus. When rocker arm fell off the valve would stay closed by the pressure from valve spring. And the other intake valve for cylinder #4 is still functioning and the engine runs fine at lower RPM.
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
I'm calling this BS. I will change my mind if he comes back with pictures.
I was thinking this right from the initial post.
I would like to see some proof before jumping to conclusions.
Pictures, copies of the service documentation from the dealer when the engine was replaced, etc.
This sounds like something Mango would come up with to discredit Mazda.
 

shadonoz

SkyActiv Member
Contributor
:
State of Jefferson
:
2017 CX-5 GT AWD+
So what we need is for every 18 and 19 NA owner to go out and floor it at 4k and report back.
 
My guess is that some engines were not assembled correctly or bad parts were used, in order for a rocker to fall off. The spring tension will keep it in place. Maybe a spring broke. And it blows my mind that an engine can run with a rocker sitting under the valve cover somewhere and the valve stuck open. Did you hear any loud noise at any point come from the motor?
You obviously havent read the whole thread. To understand what is happening go back and read the whole thread. No springs broke. These are hydraulic lifters. The problem is with the cylinder deactivation.
 
I'm calling this BS. I will change my mind if he comes back with pictures.
My wife and I could have died. Do not call bs. Call the Mazda dealership in Pasco Washington. I have a lot better things to do than make up stuff to randomly post on a Mazda forum. I am trying to get the word aout about this so maybe it will save a life. If you choose to disregard that is your option but DO NOT call me a liar!
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
So what we need is for every 18 and 19 NA owner to go out and floor it at 4k and report back.
(drive2)

Honestly I can't imagine someone can come up a fake story about a fallen rocker arm on cylinder #4 in such detail. Coincidentally just 9 days ago there's another report by jjm86m with exactly the same symptom and the same error code of misfire on cylinder #4.

IMO the report by OP is legit.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
My wife and I could have died. Do not call bs. Call the Mazda dealership in Pasco Washington. I have a lot better things to do than make up stuff to randomly post on a Mazda forum. I am trying to get the word aout about this so maybe it will save a life. If you choose to disregard that is your option but DO NOT call me a liar!
This's a Mazda forum and you shouldn't be surprised when you write a negative post some people here would choose to bury their head in the sand and defend Mazda's reputation to death. Just post some evidence and they'll have nothing more to say.
 
:
2018 CX-9 Sig
:
2014 CX-5 GT
My wife and I could have died. Do not call bs. Call the Mazda dealership in Pasco Washington. I have a lot better things to do than make up stuff to randomly post on a Mazda forum. I am trying to get the word aout about this so maybe it will save a life. If you choose to disregard that is your option but DO NOT call me a liar!

I believe you. Cars fail. I don't know if this is a big issue or not. There are close to 200K of these on the road and I have not heard many mentions of this. Yours honestly is the first.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
I believe you. Cars fail. I don't know if this is a big issue or not. There are close to 200K of these on the road and I have not heard many mentions of this. Yours honestly is the first.
No, his is the second in recent days.

There's another report just 10 days ago with exactly the same symptom and the same error code of misfire on cylinder #4.

18' CX5 Limp Mode at Redline

Most CX-5 owner won't push their engine over 4,000 rpm, hence the symptom won't show even if one of the the intake rocker arms on cylinder #4 has dislodged.
 
hopefully you guys can open that so all of you doubters out there will understand this is not a joke. I sincerely hope none of you have to experience this. I can't emphasize enough how important this is. You may be driving around with this problem as we speak. the only way you will know is if you get the RPMs high enough and maintain them for a bit. If the rocker is off your car will go into limp mode. They will need to reflash your PCM to the correct logic and obviously address your engine issue.
Thank you to all of you out there who have been believing me and backing me up.
 
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