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

Was concerned about the CD at first, but now with over 30k miles on our ‘19 (had update done around 5k), not longer worried about it. And would any day take cylinder deactivation over the incredibly-annoying stop/start that most vehicles seem to come with now.
 
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2018 CX-5 Sport
I don't think Mazda NA even fully understands the issue, probably only a few engineers in Japan understand the condition in which the rocker can be displaced. We hear the generic answer that there wasn't enough oil pressure and guesses that revving the motor made it displace. I think the people on this forum are responsible for Mazda even issuing a recall. Only a couple hundred out of thousands of cars had the issue occur. I hope you do write to Mazda to see what they say. I think the answer will come to us as people put more miles on their cars and report issues here on this forum. Some people must be reaching 100K miles on their cars by now that have CD. Thus far no one has reported an issue here.
 

erhayes

Contributor
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Mazda CX-5 FWD Touring
Difficult to understand why MAZDA engineers didn't foresee this ptential problem and fix it before it was introduced to the market. Ed
 
If you re-read the original post by OP Go Hawks, he couldn’t get any info about the problem after 7 months of repeated tries. Hence came over here created the thread more than a year ago hopefully someone else wouldn’t encounter similar dangerous situation he and his wife had experienced.

Yes you can suggest TotalMazda1 trying to get more details about the issue, but IMO he won’t get anything more than things we had discussed here, may be even less.

I made the comment that I agreed with TotalMazda1‘s opinion, and suggested he won’t get anything from Mazda dealers or MNAO although he can always try.

I don’t understand someone would come up here and tell us not to discuss this issue anymore because Mazda has issued a recall and apparently has fixed the problem. TotalMazda1‘s concern is for long-term when the HLA and other related parts starting to wear out a bit and it may loose some oil pressure controlled only by the software. There’s no fail-safe hardware to prevent the falling rocker arm if the oil pressure is out of specs. The result could be a fallen control arm again.

Just because it’s been many months and there’s no reports of failure, Mazda can claim the problem has been permanently fixed. A perfect example is the rear brake EPB dragging issue. Mazda at first issued a TSB with EPB module replacement. Then again issued another TSB with another revised EPB module replacement. Both revisions were software patch job but apparently the problem were still happening from time to time. Mazda eventually revised rear brake calipers with actual hardware fix, which hopefully has really fixed the problem.
Thank the Lord that there is someone on this board that totally understands my concern. Thanks Yrwei52. Guys.... I have NOT purchased a CX5, a new one WAS on the top of my list. But, I am getting rid of a 219K mile Toyota and as you see, i keep my cars longer than 3 yr leasers do. I am in it for the long haul..... if I dont go with a 2017 CX5, I will not be one of those folks, out of warranty that Mazda denies to repair with a new engine. You other folks who have relative low miles and think your AOK....well, if you are gonna get rid of it , no prob...Thanks again Yrwei52. I will not be attempting to contact Mazda, it will just frustrate me and end up with the same findings other posters have had....no solid guaranteed answer that rocker arms wont fly off....
 

shadonoz

SkyActiv Member
Contributor
:
State of Jefferson
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2017 CX-5 GT AWD+
Check out this description of GM's new 4 cyl with CD from one of my favorite geeks, Engineering Explained.

The entire video is informative and entertaining, but if it's tl;dw, the CD discussion begins at 3:23.

Unfortunately, he doesn't explain what's moving the cam slider.

I found the movement of the followers fascinating [4:26]. How could they not "jump the tracks" at speed without heavy down pressure and resultant wear, especially laterally?
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
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'18 CX-9 Signature
Thank the Lord that there is someone on this board that totally understands my concern. Thanks Yrwei52. Guys.... I have NOT purchased a CX5, a new one WAS on the top of my list. But, I am getting rid of a 219K mile Toyota and as you see, i keep my cars longer than 3 yr leasers do. I am in it for the long haul..... if I dont go with a 2017 CX5, I will not be one of those folks, out of warranty that Mazda denies to repair with a new engine. You other folks who have relative low miles and think your AOK....well, if you are gonna get rid of it , no prob...Thanks again Yrwei52. I will not be attempting to contact Mazda, it will just frustrate me and end up with the same findings other posters have had....no solid guaranteed answer that rocker arms wont fly off....
This is the question you asked. "As the engine ages and clearances widen, whats to prevent the pressure from dropping on higher mileage engines. I intend to keep my Mazda at least 200k miles.... can anyone with an in-depth knowledge of the actual software fix respond?"

If you wanted confirmation of the condition that causes the problem, you can refer to the recall and TSB info that Mazda provided (which yrwei52 referenced).

The best you can get for this cylinder deactivation problem is the description in the related Service Alerts and TSBs posted earlier in this thread.
If you want an actual answer to the question you asked, contact Mazda directly, or maybe find a software programmer who can look into this for you. That would be your best shot at getting a proper answer. The fix applied by the recall is still fairly new, so only time will tell. yrwei52's opinion on whether the software fix is viable in the long run is just that - an opinion. It's the same opinion you have. Based on the questions you're asking, I would think that you would want more than just an opinion, thus the suggestion to contact those with more information about the CD issue (or those with the means to derive the info from the resources we have).

Otherwise, if you are still in the market for a CX-5, find a used 2017 or look for 2019-2020 GT Reserve or Signature models. Those year/model trims do not have CD.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Check out this description of GM's new 4 cyl with CD from one of my favorite geeks, Engineering Explained.

The entire video is informative and entertaining, but if it's tl;dw, the CD discussion begins at 3:23.

Unfortunately, he doesn't explain what's moving the cam slider.

I found the movement of the followers fascinating [4:26]. How could they not "jump the tracks" at speed without heavy down pressure and resultant wear, especially laterally?
LOL! With all the complexity of 3-position camshaft and cylinder deactivation, this new GM L3B 2.7L turbo I4 designed for trucks has worse highway gas mileage at 23mpg on Silverado, whereas the standard 5.3L V8 has 24! No wonder the guy said “If you want the best fuel economy on the highway, get the V8 ⋯ Errrr”.
 
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