2.5T Cracked Cylinder Head/Leaking Coolant Report to the NHTSA

[EMANMAZDA]

**Moderator Edit**​

Please review the Mazda Dealer communication below. Mazda has issued a Customer Service Program (CSP11) to extend the limited powertrain warranty to 10 years/120k mi for any owners experiencing the coolant leak. Further, any owners who have paid out of pocket for these repairs may be eligible to receive reimbursement for costs incurred.

This CSP11 is applicable to the following models (if equipped with the 2.5T):

• 2016-2020 CX-9
• 2019-2020 CX-5
• 2018-2020 Mazda6

**End of Edit - Oct 18, 2024**


The cracking cylinder head, leaking coolant, and various engine failures in 2.5T engines are problems that are being reported by owners of the 2016 model year and later. Some are getting their engines replaced both within and outside of their warranty expiration date. While others are not.

If you have experienced any of the engine failures noted on this forum, please report your issues to the NHTSA, as soon as possible. Even if you have had it repaired. This helps the agency with their investigation to affect favorable action, compensation, etc. for consumers.

For your convenience, here is a link that will guide you through the process: Report a Safety Problem | NHTSA

You can also go to nhtsa.gov, and click the "report a safety problem" box, in the top right corner, and follow the prompts.

 

[csb_1237]

I made a report for my 2016 CX-9 with 78K miles that had the head leak issue.

 

[yrwei52]

The cracking cylinder head, leaking coolant, and various engine failures in 2.5T engines are problems that are being reported by owners of the 2016 model year and later. Some are getting their engines replaced both within and outside of their warranty expiration date. While others are not.

If you have experienced any of the engine failures noted on this forum, please report your issues to the NHTSA, as soon as possible. Even if you have had it repaired. This helps the agency with their investigation to affect favorable action, compensation, etc. for consumers.

For your convenience, here is a link that will guide you through the process: Report a Safety Problem | NHTSA

You can also go to nhtsa.gov, and click the "report a safety problem" box, in the top right corner, and follow the prompts.

Should post this at least to CX-5 and Mazda6 forum where the top-end models have the same 2.5T engine.

 

[EMANMAZDA]

Should post this at least to CX-5 and Mazda6 forum where the top-end models have the same 2.5T engine.

You’re right! Thank you for the suggestion.

 

[omarh93]

It doesn't look like anyone with this problem is reporting it on

Mazda CX-9 Problems

Compare Mazda CX-9 complaints, problems, & worst model years. There are 334 complaints on file for the Mazda CX-9.

www.carcomplaints.com

It would be helpful to do so

 

[csb_1237]

It doesn't look like anyone with this problem is reporting it on

Mazda CX-9 Problems

Compare Mazda CX-9 complaints, problems, & worst model years. There are 334 complaints on file for the Mazda CX-9.

www.carcomplaints.com

It would be helpful to do so

I posted my CX-9 problems there...

 

[omarh93]

This might be a stupid idea...but anyone try this if your engine is out of warranty and you got no other solution?

https://www.amazon.com/dp/ (commissions earned)

 

[csb_1237]

This might be a stupid idea...but anyone try this if your engine is out of warranty and you got no other solution?

https://www.amazon.com/dp/ (commissions earned)

This may tell the tale...

Do Head Gasket Sealers Actually Work (FULL 2yr TEST with Engine Teardown)

Replacing a Head Gasket can be difficult and expensive. Sometimes your car is not worth fixing and this is where a head gasket sealer in a bottle comes in ha...

www.youtube.com

 

[javierHere]

The cracking cylinder head, leaking coolant, and various engine failures in 2.5T engines are problems that are being reported by owners of the 2016 model year and later. Some are getting their engines replaced both within and outside of their warranty expiration date. While others are not.

If you have experienced any of the engine failures noted on this forum, please report your issues to the NHTSA, as soon as possible. Even if you have had it repaired. This helps the agency with their investigation to affect favorable action, compensation, etc. for consumers.

For your convenience, here is a link that will guide you through the process: Report a Safety Problem | NHTSA

You can also go to nhtsa.gov, and click the "report a safety problem" box, in the top right corner, and follow the prompts.

Thank you for this information. I have entered my complaint. Can't believe the Mazda USA refused to help me with any of the cost to replace my engine.

 

[PTguy]

A cracked head might require a different sealer than a leaking head gasket. After an explanation of my concern the Bar's Leaks tech support recommended carrying this product in case a leak is found: https://barsleaks.com/product/radiator-stop-leak-tablets-hdc/
(The Bar's Leaks Liquid Copper might work even better, but it'll discolor the coolant.)

With luck it'll stop the leak long enough to clean up the engine and drive to a dealer to trade in and buy a different car. (Now...if the new CX-70 was on the lots......

 

[yrwei52]

⋯ With luck it'll stop the leak long enough to clean up the engine and drive to a dealer to trade in and buy a different car. (Now...if the new CX-70 was on the lots......

After someone got burned by a newly designed (at the time) 2.5T turbo with cracked cylinder head, do you really think he or she wants another vehicle which has newly designed in-line 6 with turbo by Mazda?

I for one wouldn’t want to be a guinea pig for a brand new designed engine either.

 

[11E20]

This situation presents me with a lot to consider when I purchase a new car in 2025. I'm driving a 2019 CX-9 GT FWD that I purchased brand new and currently have a little over 21K miles on it and am NOT experiencing any coolant leak or oil leak problems.

As I'm retired and don't drive much I figure by the time I'm ready to trade it in I should only be around 30K miles and most of the folks posting here needing a new engine all appear to be higher mileage vehicles. I'm hoping that I can dodge the bullet until around March 2025.

I live in a rural area and there are not a lot of options when it comes to new car dealers; virtually all domestic brands are within a 50 mile range but for foreign brands I'm limited to Honda, Nissan, Toyota, Mazda, Kia, VW, & Hyundai. The closest BMW, Acura, Audi, Mercedes dealers are nearly two hours away...even Subaru is too exotic for my location. Of the makers available to me that I'm interested in it's just Mazda, Toyota, and Honda.

As others have said, gambling on an all new build with a car is a risky proposition and I made that mistake once with a 2010 Buick Lacrosse and it was a disaster that I won't be repeating. When I bought my CX-9 I cross shopped it with the Toyota Highlander and Honda Pilot and the Mazda came out on top in part because by 2019 I knew it had been road tested for 3 years by many owners and from lurking on this forum for a year I knew complaints were few to none about the Gen-2 CX-9. It felt like a safe purchase compared to the Pilot which owners were complaining about problems with the digital instrument cluster and infotainment screen blacking out while driving or the Highlander where the Limited Platinum trim had glitches with the Nav system and voice controls.

As of now the CX-90 is again at the top of my new car list; the Pilot just had a redesign this year and is worth a look but the Highlander has downgraded their engine to a turbo 4-cyl and reviews so far aren't great. Knowing what I do about the engineering flaws with the CX-9 engine that didn't become known until after about three years out, I don't feel super confident that the inline 6 will have enough time on the road to have revealed any major issues. Also, given the way that Mazda has refused to order a recall for a problem of this magnitude certainly gives me pause.

 

[javierHere]

This situation presents me with a lot to consider when I purchase a new car in 2025. I'm driving a 2019 CX-9 GT FWD that I purchased brand new and currently have a little over 21K miles on it and am NOT experiencing any coolant leak or oil leak problems.

As I'm retired and don't drive much I figure by the time I'm ready to trade it in I should only be around 30K miles and most of the folks posting here needing a new engine all appear to be higher mileage vehicles. I'm hoping that I can dodge the bullet until around March 2025.

I live in a rural area and there are not a lot of options when it comes to new car dealers; virtually all domestic brands are within a 50 mile range but for foreign brands I'm limited to Honda, Nissan, Toyota, Mazda, Kia, VW, & Hyundai. The closest BMW, Acura, Audi, Mercedes dealers are nearly two hours away...even Subaru is too exotic for my location. Of the makers available to me that I'm interested in it's just Mazda, Toyota, and Honda.

As others have said, gambling on an all new build with a car is a risky proposition and I made that mistake once with a 2010 Buick Lacrosse and it was a disaster that I won't be repeating. When I bought my CX-9 I cross shopped it with the Toyota Highlander and Honda Pilot and the Mazda came out on top in part because by 2019 I knew it had been road tested for 3 years by many owners and from lurking on this forum for a year I knew complaints were few to none about the Gen-2 CX-9. It felt like a safe purchase compared to the Pilot which owners were complaining about problems with the digital instrument cluster and infotainment screen blacking out while driving or the Highlander where the Limited Platinum trim had glitches with the Nav system and voice controls.

As of now the CX-90 is again at the top of my new car list; the Pilot just had a redesign this year and is worth a look but the Highlander has downgraded their engine to a turbo 4-cyl and reviews so far aren't great. Knowing what I do about the engineering flaws with the CX-9 engine that didn't become known until after about three years out, I don't feel super confident that the inline 6 will have enough time on the road to have revealed any major issues. Also, given the way that Mazda has refused to order a recall for a problem of this magnitude certainly gives me pause.

Personally, I would never again buy a Mazda. I would stick to Toyota - Lexus. Mazda USA clearly does not stand behind their product and there customers. I recommend you sell it just before your warranty expires. Good luck.

 

[copofop]

Personally, I would never again buy a Mazda. I would stick to Toyota - Lexus. Mazda USA clearly does not stand behind their product and there customers. I recommend you sell it just before your warranty expires. Good luck.

I second this. If it was up to me, I would trade mine in and down size to a small all electric like a Chevy Bolt and would have money left over from trading in my CX-9. Wife would not approve though so here I am keeping the CX-9 and walking on egg shells for this potential cracked cylinder head to happen.

 

[javierHere]

It doesn't look like anyone with this problem is reporting it on

Mazda CX-9 Problems

Compare Mazda CX-9 complaints, problems, & worst model years. There are 334 complaints on file for the Mazda CX-9.

www.carcomplaints.com

It would be helpful to do so

I just added my complaint. Thanks.

 

[PTguy]

The new hybrid powertrains will have the naturally aspirated (I think) 2.5 engine. I haven't heard of problems with those, and I'd sure trust the turbo 2.5 after the dates of the problem engines. I understand leaving a brand that didn't treat you well.

My 2016 has been nearly flawless. With the current news I do keep the engine temperature gauge in the display all the time, and I carry a box with a gallon of green juice and the stop-leak pills, just in case.

 

[yrwei52]

The new hybrid powertrains will have the naturally aspirated (I think) 2.5 engine. I haven't heard of problems with those,

Well, Mazda’s 2.5L NA starting 2018 has added cylinder deactivation. It also suffers cracked cylinder head issue as well as failing switchable hydraulic lash adjuster problem:

Cracked Cylinder Head with Oil leaking...How common is this?

NA CX-5 with Cylinder Deactivation Engine Repairs - Report In

Cracked cylinder head - 2019 Mazda CX5 GT

Cracked cylinder head (2018 CX-5)

and I'd sure trust the turbo 2.5 after the dates of the problem engines. I understand leaving a brand that didn't treat you well.

Even if Mazda supposedly has modified the cylinder head on the 2.5T, but sometimes the modification can’t overcome the limitations from the initial design. We’ll never know for sure the fix has truly resolved the weak cylinder head issue until there’s enough time to prove.

My 2016 has been nearly flawless. With the current news I do keep the engine temperature gauge in the display all the time, and I carry a box with a gallon of green juice and the stop-leak pills, just in case.

Green juice? Hope you’re talking about blue/green Mazda’s FL-22 coolant.

And I wish my 2016 CX-5 GT AWD has the coolant temperature gauge, not just the blue and red idiot lights ⋯

 

[FriendlyExp]

All, there is a class action investigation into this issue: https://www.sauderschelkopf.com/inve...investigation/

 

[EMANMAZDA]

All, there is a class action investigation into this issue: https://www.sauderschelkopf.com/inve...investigation/

Thank you for sharing.

 

[csb_1237]

All, there is a class action investigation into this issue: https://www.sauderschelkopf.com/inve...investigation/

I have signed up. Wonder what will come of it, if anything...