Poll 2.5T Coolant Leak/Engine Replacement. What can be done to prevent?

Who is having coolant leak issues and have had their engines replaced?

  • Yes

    Votes: 10 27.8%
  • No

    Votes: 26 72.2%

  • Total voters
    36

sm1ke

Work In Progress..
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Contributor
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Canada
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'18 CX-9 Signature
So shiny! Wish there was a way to tell if there were revisions made to the new engine to address these potential coolant leaking issues.
 
Picked up the cx9 this afternoon and man, its great to have it back! Such an awesome vehicle! As far as root cause per the mazda hotline that they called: cracked head. Mazda Hotline reccomended the engine replacement. The engine they put in is part # PYZ3-02-300D....the latest revision, 12,000 mile warranty. They told me it was the latest revision and that it would eliminate the issue i had....thats all i could get out of them. The car is running perfect!
 
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Winnipeg Canada
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2017 CX-9 GT
I looked up that part number on this site:

https://www.zoomzoomnationparts.com...-PARTIAL---CONVENTIO/98566026/PYZ302300D.html

It asks you to select a model year to check if it fits. Just for fun I clicked on 2017, the year mine was made. It told me it didn't fit. That's odd. I tried 2016 and 2018 as well, again, no fit. However, 2019 fit as do 2020 and 2021. So my guess is this part came out for the 2019 model years and their computer just isn't aware that it fits on older models as well. So I think someone was theorizing that 2019+ models had some engine change that fixes this issue. This kinda supports that.
 
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2007 Mazda CX-9 Touring
Just wondering do the regular 2.5 engines without the turbo have this same problem with the coolant leaking?
 
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2007 Mazda CX-9 Touring
Hi Andrewnds. Based on your answer i suspect that they just took the regular skyactiv 2.5 and slapped a turbo on it without upgrading the heads or the bottom end of this engine. As the other poster said mazda told him that there was a crack in the head. Makes you wonder what they were thinking when they did this, should have been with upgraded heads and bottom end.
 
Hi Andrewnds. Based on your answer i suspect that they just took the regular skyactiv 2.5 and slapped a turbo on it without upgrading the heads or the bottom end of this engine. As the other poster said mazda told him that there was a crack in the head. Makes you wonder what they were thinking when they did this, should have been with upgraded heads and bottom end.
To be fair, it’s still not a super common problem. People also turbo older Mazda engines without issues (thinking specifically Miata’s) so the “heads and bottom end” could have passed through Mazda’s engineering team and been given the green light to turbo as is. But as @youri said, you are making an assumption they did nothing other than “slap a turbo” on the existing engine. I guarantee you they did not just decide one day to throw that turbo on and push it customers without testing it.
 

andrewnds

2021 CX-5 Signature, 2012 Mazdaspeed3 Tech Pkg.
Hi Andrewnds. Based on your answer i suspect that they just took the regular skyactiv 2.5 and slapped a turbo on it without upgrading the heads or the bottom end of this engine. As the other poster said mazda told him that there was a crack in the head. Makes you wonder what they were thinking when they did this, should have been with upgraded heads and bottom end.
I have no "official" answer to that, but from my knowledge they wouldn't do that. They didn't do that with the last gen turbo DISI engine and I doubt they'd do it now. I couldn't see that being possible, too much would need to be changed (compression ratios, stronger connecting rods, more fueling etc).
 
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ACT, Australia
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2016 CX9 Azami
I just had mine inspected at by Mazda and an independent specialist (pressure test, ocular inspection, etc.). All clear at 104,500+ kms. It seems that the issue is fairly rare, considering the number of CX-9's sold (well over 110,000 units globally) vs the reported issues. Would be good to find out if the smaller models with the same engines have similar issues.
 

JPL

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2018 Mazda6, CX-9
Hi Andrewnds. Based on your answer i suspect that they just took the regular skyactiv 2.5 and slapped a turbo on it without upgrading the heads or the bottom end of this engine. As the other poster said mazda told him that there was a crack in the head. Makes you wonder what they were thinking when they did this, should have been with upgraded heads and bottom end.

No, Mazda definitely modified the standard 2.5 to handle the extra load and heat of the turbo right from the start in 2016. I remember Dave Coleman specifically saying this before the CX-9 launch. (Coleman is a lead engineer at Mazda).
 

far4ngn

2016 CX-9 GT
I have a 2016 CX-9 with 90K that started leaking anti-freeze on the rear of the engine 3 weeks ago. It has been at the dealer for two weeks and the diagnoses have ranged from cracked block to cracked head to the current diagnosis of warped head. Supposedly plugs in the head started leaking and therefore the head couldn't cool itself and then the head overheated and warped.

Luckily I have an extended warranty that covers everything to 100k without a deductible. Mazda has recommended replacement of the engine, but the last two weeks have been spent removing it and disassembling it to provide documentation to the warranty company. Heads are not even available from Mazda, so I'm getting pretty frustrated with the time that is being wasted. The dealer says that they can't get me an ETA on a replacement engine until the they actually have approval and order it.

I spoke to Mazda USA and they pretty much said "good thing you bought an extended warranty". I've owned at least 10 cars that I've driven beyond 100k and I've never had any issue of this severity level.
 
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2017 CX9 GT AWD
I spoke to Mazda USA and they pretty much said "good thing you bought an extended warranty".

Wow, this statement from Mazda is ridiculous.

I thought we've had people here that were out of warranty (no extended either) and Mazda was replacing the engine anyway at no cost to the owner.

Anyone want to comment and confirm their experiences if their engine was out of warranty with this coolant failure?
 
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I want to answer this poll, but I fall into the maybe category. I’ve got a 2018 with 39k miles, random misfires and occasional coolant smells (and what looks like low coolant in the overflow when cold). My problem hasn’t been diagnosed, so I can’t say yes but it’s starting to seem like it might be this issue.
 
Is it just me or do these failures happen around 50K - 60K miles? Has anyone seen some encounter this issue with a more high mileage vehicle? Perhaps it's the sort of problem where if it will present itself it will do so within a certain time otherwise you have a "good one" and it'll just last as long as any other engine. In other words, those that will fail will fail "early", or whatever you call 50K - 65k miles.

Having said that, mine is at the 65,000 mile mark (105,000km), so I might be right at that moment of truth myself! (last I checked my coolant level is right where it should be, knock on wood)
My wife's 2017 cx-9 is having the engine replaced right now with 74,xxx miles on it.
Luckily we had the extended warranty to cover it. We've been driving a 2021 cx-9, and I feel like there is a lag from the time you put your foot down to when it engages vs our 2017.. I could be wrong, but idk.
 

speed3chris1

2021 Signature CX-9
I had a 2016 Sig and my new 2021 Sig drive the same. Very little turbo lag with both cars. The drive train seems to feel the same to me.
 
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Winnipeg Canada
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2017 CX-9 GT
Saw this on Facebook
Screenshot_20210810-211247.png
 
Without some sort of verification from Mazda or a lot more people that are supposedly receiving those 1000+ engines, I wouldn’t trust a FB post. Who is this guy? At any rate, let’s say they are correct and this is the second half of all the engines that have been replaced, that’s still 2,000 out of 145,019 sold from January 2016 to July 2021. That gives a failure rate of 1.3%. Even doubling that to 4,000 engine replacements is only 2.6%. While it does suck for those that need to get their engines replaced, and I do feel bad for those that have to go through it, it still doesn’t seem to be widespread enough to really worry about. Keep some healthy awareness that it could happen, but I wouldn’t expect it to just be a matter of time. Maybe in two years I’ll eat my words and the vast majority of the pre-reinforced engines will be replaced, but I just don’t see that happening.
 
I agree that it is too early to press the panic button. As far as stats goes however, i wouldn’t include models years past 2018 for a good representation. The 2019 and younger are unlikely to have enough mileage on them for this issue to come up in significant numbers. Plus the pandemic in my opinion is slowing the down the rate of issues. I wish i would be driving my 2018 more (like I usually do) so that normal issues would come while still under the initial warranty. At this rate of driving, items normally dealt with under warranty will break a year or two later when I am out of it.