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

Note the reference to SA-041/18 in the above under Repair Procedure in the event of discovered broken/dislocated rocker arms.

Here it is on the NHTSA website. It outlines the steps the mechanic/dealer is to take.
Mazda Service Alert no. SA-041/18 issued on 12/06/2018 where you posted from NHTSA is for fallen or broken rocker arm with cylinder deactivation. The Service Alert no: SA-015/19 issued on 04/08/2019 where t.suv posted earlier from NHTSA is for fallen or broken rocker arm AND broken front and rear oil control valves with cylinder deactivation. For broken control valve, the Service Alert doesn't say the engine replacement is required. This makes me further believe there's more involved on rocker arm falling problem.

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Mazda Service Alert SA-041_18_01.jpgMazda Service Alert SA-041_18_02.jpg

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Mazda Service Alert SA-015_19_01.jpgMazda Service Alert SA-015_19_02.jpg
 
So if Mazda is replacing engines without the force of government or lawyers, do you think we can infer that the number of affected vehicles is small?
Yes I believe the number of affected CX-5's should be very small at this time. But the POTENTIAL is there, and nobody knows when the rocker arm would be fallen off. I believe this uncertainty is more dangerous as there's no warning in advance. That's why OP's wife is afraid of driving her CX-5 now even though Mazda claimed the problem has been fixed.

I changed my mind getting a new 2018 CX-5 when I learned Mazda suddenly added cylinder deactivation for 1 (FWD) and 0 (AWD) MPG benefit. Now I definitely won't even recommend this 2.5L with CD to any of friends and family.
 
Yes I believe the number of affected CX-5's should be very small at this time. But the POTENTIAL is there, and nobody knows when the rocker arm would be fallen off. I believe this uncertainty is more dangerous as there's no warning in advance. That's why OP's wife is afraid of driving her CX-5 now even though Mazda claimed the problem has been fixed.

I changed my mind getting a new 2018 CX-5 when I learned Mazda suddenly added cylinder deactivation for 1 (FWD) and 0 (AWD) MPG benefit. Now I definitely won't even recommend this 2.5L with CD to any of friends and family.

I was looking at the CX-5 back in 2018 before stuff caused me to delay my decision. Had I realized that CD was new for that model year, I would not even have considered it...I am not an "Early Adopter." I only went with the turbo because it has been around in the CX-9 for a while.

Thanks for your reply on the NHTSA Bulletin I linked. I find it interesting that the one I posted (that was referred to in t.suv's Service Alert) calls for verifying oil change records as part of the process, while the one t.suv posted that specifically says to look for contamination and debris does not call for looking at oil service records. It seems they're not even looking at lack of maintenance as a source of the debris.
 
So in all, our engines have rocker arms that are held down by gravity like jenga, and one wrong pressure from the oil system will bring it toppling down...
 
Here's the latest update I have.

- A new engine has been authorized by Mazda Corporate.
- According to the technician this is a new engine, not a refurbished one
- I pressed the service guy to call the Mazda Field Service Engineer to find out why they are confident this engine won't fail. They ultimately came back to the same answer they gave to Go Hawks. The PCM update is sufficient to keep oil pressure to keep the rocker arm from falling off.
- Should take about 1.5-2 Weeks for engine delivery and installation


I'm currently in a 2019 CX5 Touring courtesy of the dealership and have put on about 1000 miles since I got it. I have been trying all sorts of different combinations to see if this is repeatable with this particular car. I've gone to redline from a stop, from a constant 45mph to redline, from 60mph to redline and downshifting to get to redline. I haven't had any issues and the loaner drives just fine.

If its gnawing at you to know if you're affected, here are some of my observations and thoughts regarding my case.

1. I observed noticeable slowness while merging into and out of traffic on the freeway. I would see a gap i would want to merge into but the car would be too sluggish to react when I gave it gas and the gap would close and I'd miss the merge. I attributed this to the fact that I was used to driving an Acura RSX and went from zipping around in traffic to an SUV. I didn't have a baseline comparison. The loaner CX5 is much easier to maneuver in traffic and I can tell a difference. Take note if you feel like your CX5 is unusually sluggish.

2. City Gas Mileage. My city gas mileage was really poor 17-20mpg. I thought my aggressive driving style led to the terribleness in city mpg but the rocker arm falling off may could have been more of a contributor. On the 19' touring my city gas mileage is much better (~25mpg). The 19' is a FWD compared to my AWD but 17-20 was still low in my opinion. My highway mileage was actually not bad and actually stayed in the 29-31 range.

3. Noise. when slowing moving through a parking lot, or at a stoplight I would sometimes hear inconsistencies in engine idle (possible rattle?). Nothing ever enough for me to complain to the dealership about bc it was inconsistent and super faint. I am speculating that was due to the rocker arm rattling around. I haven't heard that on the 19' I'm driving.

If you're have the combination of issues I've noted above then you may want to check with your dealership to discuss the symptoms you are seeing. I would avoid allowing them to update the PCM because if you're rocker arm has fallen off that will only mask the problem because even with the rocker arm off, the flash does "fix" the issue.

I have an open case with Mazda Customer Support Right now and I want to talk to them about having them add the affected PCM versions to the TSB. It doesn't do the service guys any good if they don't know which PCM versions are bad. They're only reactive to the codes thrown or customer complaints of low power. If it truly is a case of the wrong PCM version then its not that hard to identify if you're affected. Maybe that makes too much sense for Mazda.

Did they finish your motor swap yet?
 
Just picked up the CX5 today. Seems to drive normally. New Engine, New ATF, New Oil. Haven't really pushed the engine bc I want to take it easy and break it in. But so far so good. Next step is to go onto NHTSA and file an official complaint
 
Just picked up the CX5 today. Seems to drive normally. New Engine, New ATF, New Oil. Haven't really pushed the engine bc I want to take it easy and break it in. But so far so good. Next step is to go onto NHTSA and file an official complaint
Thanks for the update.

I wonder why you got new ATF for an engine replacement?

I still believe there's something Mazda either doesn't want to tell, or Mazda doesn't know the real reason why the rock arms are falling off. If the hardware has no issues, they could easily have the tech to put the fallen rocker arm back to the position and update the PCM software. Replacing the entire engine for this problem makes me suspicious. Once enough people who encountered this problem and reported to NHTSA, NHTSA could force Mazda to initiate a safety recall to explain and fix the problem from the root.
 
does anyone know the updated PCM version number for CD 'fix' ???
and how do you check the number, does the dealer have to look or can I ???
thanks ........
 
I was thinking about why they replaced the engine and the best I could come up with beside mazda wanting to investigate is that there could be extensive damage that is hard to diagnose. The fallen rocker arm could damage a cam and send shavings of metal throughout the engine. The Cylinder is still firing but there is nowhere for the exhaust gas to go so there could be damage associated with that as well. I'm not convinced it's as simple as throw a Rocker arm back on and call it a day.
 
I was thinking about why they replaced the engine and the best I could come up with beside mazda wanting to investigate is that there could be extensive damage that is hard to diagnose. The fallen rocker arm could damage a cam and send shavings of metal throughout the engine. The Cylinder is still firing but there is nowhere for the exhaust gas to go so there could be damage associated with that as well. I'm not convinced it's as simple as throw a Rocker arm back on and call it a day.
From owner's point of view of course we want a new engine. But for Mazda, replacing a new engine is costly, and they won't replace it unless it's really necessary. Looking at the picture with fallen rocker arm in Service Alert, the rocker arm seems sitting there harmlessly and can't cause any other damages.

The same picture shows it's one of the intake rocker arm fallen off. There's another intake valve for cylinder #4 which is still functioning. That's why cylinder #4 is having no issues during the lower rpm's, and it only feels lack of air during higher rpm's.

BTW, how did you get the firmware version out of your PCM?
 
Can anyone with a 18 or 19 CX5 verify if there is noticeable vibration from the engine when sitting in Park after a commute (~ 15-20 miles). I'm noticing some vibrations and its happening while the A/C is off, in Park, after a drive. Idle holds at a constant speed and the vibrations disappear when I rev the engine to about 2K RPM. Can't remember if this has always been like this or if this is something new.

Other than vibration everything else seems to be running normally.
 
Can anyone with a 18 or 19 CX5 verify if there is noticeable vibration from the engine when sitting in Park after a commute (~ 15-20 miles). I'm noticing some vibrations and its happening while the A/C is off, in Park, after a drive. Idle holds at a constant speed and the vibrations disappear when I rev the engine to about 2K RPM. Can't remember if this has always been like this or if this is something new.

Other than vibration everything else seems to be running normally.

Vibration is somewhat subjective. I don't think mine has noticeable vibration. I wish there was a test that we both can do, like attach a long zip tie to the steering wheel or some other interior part and video how much the tip of the zip tie vibrates.
 
Can anyone with a 18 or 19 CX5 verify if there is noticeable vibration from the engine when sitting in Park after a commute (~ 15-20 miles). I'm noticing some vibrations and its happening while the A/C is off, in Park, after a drive. Idle holds at a constant speed and the vibrations disappear when I rev the engine to about 2K RPM. Can't remember if this has always been like this or if this is something new.

Other than vibration everything else seems to be running normally.

I will take note tonight when I get home after my commute, and see what I can see.

What I CAN tell you, is there is a noticeable vibration every time the AC Compressor comes on in mine. Every 15-20 seconds or so, you can hear it click on and then there's a momentary vibration felt - a LOT more than my old car used to do.
 
Can anyone with a 18 or 19 CX5 verify if there is noticeable vibration from the engine when sitting in Park after a commute (~ 15-20 miles). I'm noticing some vibrations and its happening while the A/C is off, in Park, after a drive. Idle holds at a constant speed and the vibrations disappear when I rev the engine to about 2K RPM. Can't remember if this has always been like this or if this is something new.

Other than vibration everything else seems to be running normally.

My mother in laws 2018 2.5L vibrates at idle noticeably more than my 2013 2.0L. Not what I would call abnormal or worrisome though. Shes got less than 10k on it and Ive done the scheduled maintenance myself. Ran it nice and hard the last time she visited to check for that rocker arm symptom being discussed here. Idle seemed the same cold vs the end of my drive and its definitely more perceptible than my 2013.
 
My mother in laws 2018 2.5L *vibrates* at idle noticeably more than my 2013 2.0L. Not what I would call abnormal or worrisome though. She*s got less than 10k on it and I*ve done the scheduled maintenance myself. Ran it nice and hard the last time she visited to check for that rocker arm symptom being discussed here. Idle seemed the same cold vs the end of my drive and it*s definitely more perceptible than my 2013.
This's normal as SkyActiv-G 2.0L is smoother than 2,5L. For a 4-cylinder, 2.0L is the best displacement for smoothness and light weight. That's why Mazda really should put turbo to its SA-G 2.0L and implement it to the CX-5. 2.5L simply is too big on displacement for a 4-cylinder and it will vibrate. Mazda has to add a heavy balance shaft into 2.5L just to smooth out the vibration.
 
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This's normal as SkyActiv-G 2.0L is smoother than 2,5L. For a 4-cylinder, 2.0L is the best displacement for smoothness and light weight. That's why Mazda rally should put turbo to its SA-G 2.0L and implement it to the CX-5. 2.5L simply is too big on displacement for a 4-cylinder and it will vibrate. Mazda has to add a heavy balance shaft into 2.5L just to smooth out the vibration.

Exactly, thanks for further clarifying. Vibration can be subjective as someone else mentioned, but using my car seemed to be a good qualitative benchmark for the reasons you point out : )
 
Going to put the new engine to the test for the next couple of weeks. We have put around 3000 miles on this engine and all seems well. Most of these miles are just in town driving due to the fact that my wife still does not trust the car totally. We are heading out on a road trip from Oregon to San Diego with multiple side stops along the way. My wife wants to take our truck but we have decided to give the Mazda a chance and see how it does. Hopefully we have a better experience in California this time than we did last October. Wish us luck!
 
Going to put the new engine to the test for the next couple of weeks. We have put around 3000 miles on this engine and all seems well. Most of these miles are just in town driving due to the fact that my wife still does not trust the car totally. We are heading out on a road trip from Oregon to San Diego with multiple side stops along the way. My wife wants to take our truck but we have decided to give the Mazda a chance and see how it does. Hopefully we have a better experience in California this time than we did last October. Wish us luck!
Yeah drive safely and please report us back how the new engine is doing. At least you've avoided the heat wave for the last couple of days in Bay Area where the temperature reached 105F in San Jose!
 
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