2018 CX-5 head gasket issues?

@yrwei52, thanks for the info. The TSB isn't opening as you said. Is there a specific vin range impacted?

With TSBs, do the dealership fix them automatically on Mazda's dime? Or do owners have to pay?
Here’s the TSB on EPB brake dragging issue on 2016 CX-5. If you hear any noise、noticed burning smell、feel dragging、found premature and uneven pad wear on rear brakes, you got problem on your 2016 CX-5 which is the first year Mazda offers the Electrical Parking Brake on CX-5. Mazda had issued several TSBs for the problem with different fixes, eventually decided to replace rear disk calipers with revised version. There’s a date code on the caliper, which can tell if the 2016 CX-5 has the TSB applied with new revised calipers. See the TSB for details.
 

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  • Brake Noise from REAR BRAKE_Trace of Rear Brake Dragging 5.pdf
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They don't bother me because I have not experienced those issues. My purchase was a dealer loaner, certified with extended warranty, with 4k miles when I bought it, so one or more of these TSBs may have been applied. Dunno. Should I be on the lookout? Sure. Am I alarmed? Not really. The operative terms in the TSBs are "some customers" and "some vehicles". How many? How many encountered the dangerous conditions bringing about the recall? Not many. Like any other vehicle, if it runs good, sounds good, feels good, the mpgs stay constant, and it doesn't flash an idiot light then I'm good.

Since the issue at hand is CD, have you pored over the the TSBs for the non-CD turbos or another maker's vehicle in this class with a reputation for reliability? I'd guess you'll find "some customers" and "some vehicles" having some comparable issues if not worse. Or consider the non-CD 2017 CX-5's 1/5 CR reliability for the brakes. Choose your poison, or better put, odds of poisoning.

I'm not blind to potential problems like carbon buildup. I concede to using Top Tier gas in the CX-5. I'm fortunate to have long, flat, straight, lightly traveled roads all around my house with good visibility for cops, so every couple weeks I floor it up to 6,000 rpms and about 85 mph. Maybe that does some good as a preventative measure. Maybe not, but it does get my blood stirring.

I don't mean to diminish the experiences of others encountering problems, and there are knowledgeable people here who can help. Had I not been here I would not have been turned on to the aforementioned TSB that improved the vehicles driving characteristics. But when considering reliability in making a purchase it comes down to odds, not certainties.
 
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Your critique may be valid for 2018's and to the point for the OP's consideration. I speak from the experience of a 2020 owner. The rocker arm recall does not apply to 2020's. In fact there are no recalls at all on the 2020, pretty unusual these days for a car on the road for 1.5 years. I've scanned through the engine TSBs for 2020 and don't see anything alarming. ⋯
My opinion against cylinder deactivation is based on its design principle and past history, not on statistics. If a flaw may cause one fatal incidence in an unexpected situation in many chances, we still want to prevent it as the case can be severe if it happens. Use the EPB dragging TSBs mentioned above as an example, when the first report appeared on the issue, Mazda decided to use modified software to have better control on rear disk calipers. It’s normal to handle such problem as this’s the cheapest and easiest way to resolve an issue. Hence the initial TSB instructed a EPB control module replacement. After a couple of follow-up TSBs with additional revisions, the EPB control module replacement for the same issue, Mazda finally has to modify the rear brake calipers which apparently are the root cause of the problem. Hence a 3rd TSB finally issued calling for caliper replacement. This’s a hardware fix, after a couple of software fixes failed.

If you notice, those TSBs listed by edmaz are the continuation of old TSBs with revisions, and the model years on CX-5 not only affects cylinder-deactivation equipped 2.5L, but also extended from 2018 into 2021 with additional revisions. The recall on the fallen rocker arms is a software fix, which basically changed the oil pressure controlling the switchable hydraulic lash adjusters (HLA) used on cylinder #1 and #4 that can be de-activated. Apparently the modified software, although it may have prevented rocker arms falling, isn’t good enough to cover every areas, now the latest TSB has offered a modified switchable HLAs, a hardware fix. The 2.5L in 2020 CX- has the same switchable HLAs as 2018’s, hence the 2020 is included in the latest TSBs. Some manufactures such as Honda when they came out the PCM fix on cylinder deactivation, the software basically has reduced the occurrences of cylinder deactivation. It has never fixed the root cause of the problems unless the PCM totally shuts down the CD function. Sometimes even with a perfect software (not possible) to control the well-designed hardware, they can never overcome the flaws by design principle, the cylinder deactivation.
 
... The operative terms in the TSBs are "some customers" and "some vehicles". How many? How many encountered the dangerous conditions bringing about the recall? Not many. ...
IMO it's impossible for anyone outside of the Mazda organization to know how many instances of these issues have been happening. This group of 2018-2021 vehicles is for the most part still under one or both of the warranties, and we rarely hear about an issue that the automaker fully covers under warranty.

The much more significant question (for me anyway), is what's going to happen AFTER the powertrain warranty expires. What are these CD-related issues going to look like 5-10 years down the road? Now anyone who typically trades in around the time the warranty ends doesn't care about such things, but that's not me. I buy new, and keep them a minimum of 10 years and often a lot longer (sometimes passing them along to other family members). So 'how many' might have quite a bit of a different meaning for you than it does for me. However, I'm not saying that as a criticism of your perspective in any way. There's no right or wrong with kinds of things.



... Since the issue at hand is CD, have you pored over the the TSBs for the non-CD turbos or another maker's vehicle in this class with a reputation for reliability? ...

Frankly I have no interest whatsoever in finding out about problems in vehicles aside from the ones we own, except when another buying cycle comes around. And would I feel any better if I found out that a number of other vehicles had similar or worse problems? No, not a bit.

Now if someone wants me to compare my CX-5 to another vehicle, then I'll compare it to our 2011 2.0L Mazda3, which is still in the family and running well. That 3i a WONDERFULLY reliable vehicle, with no significant/major systemic issues discovered since it was built 10 years ago. Aside from doing regular maintenance, I've replaced an O2 sensor and that is it. Just give me that level of quality and dependability, and I'll never ask for anything more.

... They don't bother me because I have not experienced those issues. ...

Well, it's good that you're more relaxed about these TSBs than I am. And I certainly hope that you, I, and everyone here who owns one of these engines never has any of these issues.
 
.... If you notice, those TSBs listed by edmaz are the continuation of old TSBs with revisions, and the model years on CX-5 not only affects cylinder-deactivation equipped 2.5L, but also extended from 2018 into 2021 with additional revisions. ...
Yes indeed, the floundering on the part Mazda is almost a disturbing as the issues themselves. And this prior floundering also leads one to believe that none of those TSBs is going to be the 'final' word. Also I can't help wondering when the next CD-related issue is going to be showing up. I'm of course hoping it won't, but also not wildly optimistic about there being no additional (i.e. new) CD issues happening with our engines in the future.
 
Frankly I have no interest whatsoever in finding out about problems in vehicles aside from the ones we own except when another buying cycle comes around.
That's a valid practice which I share. But here we are after the fact in an imperfect world where all vehicles are imperfect, some more than others. Rather than anecdotes I'd rely on CR or other credible aggregators of reliability data to see who is less imperfect, who presents the best odds for trouble free driving and the CX-5 has consistently scored well.
Yes indeed, the floundering on the part Mazda is almost a disturbing as the issues themselves.
Is it floundering? Or is it continuous improvement? Is it fixing widely experienced problems or is it driving low incidence problems even lower? Aggregated reliability data would suggest the latter.

Did Mazda have to develop a TSB for torque resonance and dodgy jolts and shifting in the 2.5L? No. A lot of makers wouldn't even bother assuming they even could. You could have bought any of several $75,000 - $100,000 German turbos from a couple of different makers a couple of years back only to find out you're burning a quart of oil every 500-1000 miles, as as high as 10% odds in one model per a CR study, with the maker telling you "that's normal". I don't think there were TSBs for that.

People who regularly frequent specialty forums like this tend toward the obsessive perfectionist especially here where we discuss an enthusiast's brand. I share that tendency to a degree, but I draw the line at "perfection"; knowing what I know am I'm more than comfortable knowing it is not a RAV4 or CR-V in a world where I have to own something. That's from a first time Mazda owner, not a fan boy, who has been quite happy with a string of previous very reliable Toyotas and Hondas.

That's all cold comfort if you have in fact experienced a serious problem. But it still comes down to the odds.
 
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My opinion against cylinder deactivation is based on its design principle and past history, not on statistics.
Design principle is theory which comes down to the proof in the pudding, where the rubber meets the road. Some theories look great on paper, like rotary engines, but become very difficult to execute. Maybe Mazda gets there eventually; I've read they may still be monkeying with it for some possible application. Other theories don't look so good on paper but end up working out through a series of adjustments as the compromises are narrowed.

As for past history, if you mean personal history, that would be anecdotal, being the unfortunate victim of the wrong side of the odds. If you mean history in general, I don't see how you can separate that from statistics.
 
Design principle is theory which comes down to the proof in the pudding, where the rubber meets the road. Some theories look great on paper, like rotary engines, but become very difficult to execute. Maybe Mazda gets there eventually; I've read they may still be monkeying with it for some possible application. Other theories don't look so good on paper but end up working out through a series of adjustments as the compromises are narrowed.

As for past history, if you mean personal history, that would be anecdotal, being the unfortunate victim of the wrong side of the odds. If you mean history in general, I don't see how you can separate that from statistics.
I have never heard a bad idea somehow becomes a good product. Only the opposite. A good design idea on paper frequently becomes a bad product, such as the rotary engine you mentioned. Another example is the HCCI, Homogeneous Charge Compression Ignition, which Mazda had very high hope on it. Mazda had to add more components to make the idea working properly, even a traditional ignition system and super charger, which makes supposedly very simple and efficient engine to become a very complicated SPCCI, Spark Controlled Compression Ignition, or SkyActiv-X. But where’s the SkyActiv-X engine which we supposed to see in 2020?

Just found out Mazda has ditched cylinder deactivation on the 2.5L used on 2021 CX-30. I believe it’s a right move by Mazda.
 
I have never heard a bad idea somehow becomes a good product. Only the opposite.
We're going around in circles here, but I'll simply add you assume CD is a bad idea. That takes me back to whether one is going to go by anecdotes or aggregate reliability data. So, CD only buys 1 mpg and it took some time to work out driveability issues. From where I'm sitting now, 1 mpg aside, CD is neither good nor bad, it's just there, transparent now if CD was ever the issue in the first place that the TSB appears to have fixed, which leaves the totality of the experience and reliability data as pretty darn good in my book.

So, they took CD out of the CX-30 but not the CX-5. You posted they went ahead with more CD refinements in the 5 including hardware changes. I wonder why. Maybe they don't want to plow more money into an entry level model with narrow profit margins and in looking at the sales they don't need 1 more mpg in the 30 to meet fleet standards.
 
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I don't like cars that decide to shut stuff off on me. I don't like cars that have the auto stop/start "feature". I don't like companies ramming these features down my throat. I would avoid these cars.
 
I don't like cars that decide to shut stuff off on me. I don't like cars that have the auto stop/start "feature". I don't like companies ramming these features down my throat. I would avoid these cars.
All right, then. You've made up your mind that the 2018 is not for you, the issue raised in your OP. Mission accomplished.
 
I am in your court HardRightEdg about the tsb's and concern about CD. The rocker arm issue is fixed, and I don't have a tapping lifter so I'm not concerned. Yrwei52 has made it know over and over that he thinks CD is going to be a problem after the fix. He feels that the rockers should be physically retained with pins instead of having them free floating. I feel the same way with the turbos. I think 100% of the turbo trim will have engine related issues down the road, based on my personal experience and experience of friends of mine who had turbo powered cars. The turbos work almost twice as hard as a NA engine without a whole lot of physical changes from the NA engine. And with CD, which only upper trims get, the engine should last even longer than a NA engine without CD because the engine works even less. It coasts with only two cylinders firing.
 
As far as purchasing a used car, I would prefer one with fewer miles. But it is impossible to know everything about a used car. You can check the oil, look for tire wear and potential suspension issues, look for corrosion underneath, look at the jams to try and see if the car was repainted, look at the seems to see if some areas have larger gaps than others. See if it idles good and shifts good, I would want a mechanic to look it over too.
 
I think 100% of the turbo trim will have engine related issues down the road, based on my personal experience and experience of friends of mine who had turbo powered cars.
This is an anecdote. The CX9 has been on the road with the 2.5T since 2016. Turbocharging technology has had nearly 50 years of development time on automobiles and is very well understood, including its effects on combustion.

Barring a factory defect or the lack of maintenance, the vast majority of turbocharged vehicles will easily cross the 100k mile threshold and beyond whole still retaining the original turbocharger.
 
This is an anecdote. The CX9 has been on the road with the 2.5T since 2016. Turbocharging technology has had nearly 50 years of development time on automobiles and is very well understood, including its effects on combustion.

Barring a factory defect or the lack of maintenance, the vast majority of turbocharged vehicles will easily cross the 100k mile threshold and beyond whole still retaining the original turbocharger.
Truth. The poster only knows what he knows - which is based upon very limited experience. (This is my third turbo-powered vehicle, none had problems and were a delight to own and drive.). But the fact is that one third of all the light vehicles sold in the US today are turbocharged. If the technology was so flawed, manufacturers could not afford to repair/replace them all. Remember that plenty of non-turbo engines have problems too.

No disrespect intended, but the poster needs to wake up to the facts, not his biased opinions.

 
I don't like cars that decide to shut stuff off on me. I don't like cars that have the auto stop/start "feature". I don't like companies ramming these features down my throat. I would avoid these cars.

If that is the case, the answer to your question is easy. Get a 2016, 2016.5 or a 2017 CX-5. These engines do not have CD, so no need to worry about any potential long term effects regarding CD. I believe TSBs and recalls have been posted in this thread for potential issues with these MYs (EPB, LED headlights, etc.). Being a 4-5 year old car, any outstanding recalls should be completed, but you'd want to double-check with the seller to be sure.
 
If that is the case, the answer to your question is easy. Get a 2016, 2016.5 or a 2017 CX-5. These engines do not have CD, so no need to worry about any potential long term effects regarding CD.
Or a new 2021 CX-30 as Mazda has ditched cylinder deactivation on higher trims which used to have CD.
 
I am in your court HardRightEdg about the tsb's and concern about CD. The rocker arm issue is fixed, and I don't have a tapping lifter so I'm not concerned.
The rocker arm issue is “fixed” with software changes to oil pressure control. This then results the subsequent switchable hydraulic lash adjuster bubbling issue and tapping noise problem with new TSBs issued. This’s a typical scenario that you’re trying to fix one problem, but has caused another problem from the fix. The TSBs have been issued by Mazda, and they got revised in several iterations so far and extended into newer MYs. This means the potential is high that the customers will encounter such problems described in the TSBs.

Yrwei52 has made it know over and over that he thinks CD is going to be a problem after the fix. He feels that the rockers should be physically retained with pins instead of having them free floating.
Yes, to fix the rocker arm problem from root Mazda should design a physical device like other manufactures to prevent the rocker arm falling. Changing oil pressure will affect some other components unexpectedly just like those switchable HLA problems described in these new TSBs.

But I didn’t think CD is going to be a problem after the rocker arm recall fix. I had expressed my negative opinion against cylinder deactivation much earlier when Mazda suddenly announced the “American First” 4-cylinder engine with CD. I even cancelled my plan to purchase a 2018 CX-5 GT AWD because of it. Unfortunately my prediction has become the fact gradually, and I still believe this CD fiasco will be continue until Mazda finally gives up on it. Ditching CD on CX-30 is a step to the right direction.

I feel the same way with the turbos. I think 100% of the turbo trim will have engine related issues down the road, based on my personal experience and experience of friends of mine who had turbo powered cars. The turbos work almost twice as hard as a NA engine without a whole lot of physical changes from the NA engine. And with CD, which only upper trims get, the engine should last even longer than a NA engine without CD because the engine works even less. It coasts with only two cylinders firing.
I personally dislike the turbo and has always been avoiding turbo engines if possible. But the reason is different. Turbo technology is there almost as early as the ICE. Unlike the cylinder deactivation, the theory of turbo is sound. The problem has always been the longevity due to extremely high temperature. But the material and technology have improved so much on turbo, now I do believe a turbo engine is acceptable to me with much improved reliability.
 
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