Poll 2.5T Coolant Leak/Engine Replacement

[youri]

You could try the social media and media approach. The more public this lack of support becomes the more chances that Mazda will do something about it.

Here is an example of a somewhat successful media campaign for out of warranty repair: Cablegate: Toyota Agrees to Pay for Replacement as Investigation Continues

toyota cable corrosion - Google Search

 

[Trixstar]

Hey guys, just wanted to share my experience with our 2019 Signature MY with 113,000 kms. The dealer wont address the issue with the coolant leak because its a slow leak. We also have to replace two power folding mirror motors due to a design flaw and just out of warranty when we complained at 102,000 kms, shuddering under braking just happened earlier this week and a couple more minor issues. We ended up trading in the CX-9 for an Audi Q7. We were able to get $27,500 cdn for the trade at the dealer. I really appreciate the support from everyone here throughout the 3.5 years of ownership. Good luck everyone and hope Mazda addresses this coolant issue for you all.

 

[GTA-CX9]

I'd never seen this savagegeese review of the CX9 before, but he gets right into the engine design at about the 10 min mark. I know very little about how engines are designed or work, but can one sort of infer from how the turbo 4 was made, that it was maybe trying to do too much and it backfired with the cracked heads?

Just curious if this was sort of a random failure or one where it could be said that they asked for trouble/pushed the envelope too far.

Makes me wonder about the new CX90 engine's massive power.

Review | 2016 Mazda CX-9 | Plump Yet Satisfying

An expansive review on Mazda's new largest vehicle. With a new 2.5L turbo, more refinement and attention to detail, Mazda looks to compete with the Honda Pil...

www.youtube.com

 

[jal142]

I'd never seen this savagegeese review of the CX9 before, but he gets right into the engine design at about the 10 min mark. I know very little about how engines are designed or work, but can one sort of infer from how the turbo 4 was made, that it was maybe trying to do too much and it backfired with the cracked heads?

Just curious if this was sort of a random failure or one where it could be said that they asked for trouble/pushed the envelope too far.

Makes me wonder about the new CX90 engine's massive power.

Review | 2016 Mazda CX-9 | Plump Yet Satisfying

An expansive review on Mazda's new largest vehicle. With a new 2.5L turbo, more refinement and attention to detail, Mazda looks to compete with the Honda Pil...

www.youtube.com

The 2.5T failure appears to be due to a miscalculation of the stress levels in the heads by Mazda engineers. Aluminum is susceptible to fatigue failure (Google the de Havilland Comet for the most infamous case of this), and parts made of aluminum must be designed to have stress levels below the fatigue threshold of the metal, otherwise cracks will form, propigate, and the parts will eventually fail. In the case of the 2.5T engine, it is pretty clear that the stress levels are below the ultimate strength of the aluminum alloy used in the head casting (the engine would fail immediately if this were not true), but above the fatigue limit. How, exactly, this occurred has not been explained by anyone at Mazda, but this has to be pretty embarrassing for the stress analysts at Mazda.

As far as the 3.3 turbo goes, the jury is still out. Hopefully Mazda learned their lessons and didn't miss anything, but time will be the ultimate judge. On the plus side, it is really not tuned all that aggressively - 340 horsepower would be considered "massive power" for a 3.3L engine in maybe 1992. Today, that power level is nothing special. The 340 horsepower is the combined output of the gasoline and electric motors. The electric motor produces 16 horsepower at its peak, so the new gas engine is pushing maybe 100hp/liter. The current 2.5T is probably producing more power/liter when using premium fuel, so new motor is tuned similarly when compared to its predecessor. Honda achieved this level of power density 30 years ago, without a turbo or direct injection by revving to 8000+ rpm, so this engine is not exactly pushing the state of the art. There are engines for sale in pretty pedestrian cars that produce 150+ hp/liter.

 

[GTA-CX9]

The 2.5T failure appears to be due to a miscalculation of the stress levels in the heads by Mazda engineers. Aluminum is susceptible to fatigue failure (Google the de Havilland Comet for the most infamous case of this), and parts made of aluminum must be designed to have stress levels below the fatigue threshold of the metal, otherwise cracks will form, propigate, and the parts will eventually fail. In the case of the 2.5T engine, it is pretty clear that the stress levels are below the ultimate strength of the aluminum alloy used in the head casting (the engine would fail immediately if this were not true), but above the fatigue limit. How, exactly, this occurred has not been explained by anyone at Mazda, but this has to be pretty embarrassing for the stress analysts at Mazda.

As far as the 3.3 turbo goes, the jury is still out. Hopefully Mazda learned their lessons and didn't miss anything, but time will be the ultimate judge. On the plus side, it is really not tuned all that aggressively - 340 horsepower would be considered "massive power" for a 3.3L engine in maybe 1992. Today, that power level is nothing special. The 340 horsepower is the combined output of the gasoline and electric motors. The electric motor produces 16 horsepower at its peak, so the new gas engine is pushing maybe 100hp/liter. The current 2.5T is probably producing more power/liter when using premium fuel, so new motor is tuned similarly when compared to its predecessor. Honda achieved this level of power density 30 years ago, without a turbo or direct injection by revving to 8000+ rpm, so this engine is not exactly pushing the state of the art. There are engines for sale in pretty pedestrian cars that produce 150+ hp/liter.

True true, massive was a poor choice of word. But that's reassuring at least, if this new engine isn't hopefully trying to re-invent the wheel. I will time out of my lease in the early winter 2024 so I guess there will have been at least some time for the kinks to show. But clearly one is never really in the clear, these issues showing up in the cx9 only after time has passed.

 

[Liminator13]

Thought I should share to this big pile. My 2018 touring plus is officially in the cracked/warped cylinder head club. Car is at 67000 mi. right now but I think the leak was actually happening around 10,000 miles ago. I had an independent mechanic inspect it and couldn't find a source of what seemed like a very slow leak. We topped off coolant and I've driven it for about 7 months before seeing the coolant level slowly drop until this past week where it was a bit faster.

I was told there is no coolant in the oil and the car has never overheated so they are going with a cylinder head replacement. It is a CPO warranty car so should be covered. I'll update later after repairs or if there is any drama.

 

[Silly Wabbit]

Thought I should share to this big pile. My 2018 touring plus is officially in the cracked/warped cylinder head club. Car is at 67000 mi. right now but I think the leak was actually happening around 10,000 miles ago. I had an independent mechanic inspect it and couldn't find a source of what seemed like a very slow leak. We topped off coolant and I've driven it for about 7 months before seeing the coolant level slowly drop until this past week where it was a bit faster.

I was told there is no coolant in the oil and the car has never overheated so they are going with a cylinder head replacement. It is a CPO warranty car so should be covered. I'll update later after repairs or if there is any drama.

Pull your under cover off and look for dried green coolant crust. Look at the exhaust manifold (between engine and firewall)

 

[Liminator13]

Pull your under cover off and look for dried green coolant crust. Look at the exhaust manifold (between engine and firewall)

My car is already at the dealership so I can't look for these myself. Do these items you mention mean something different or scarier than the cracked cylinder head?

 

[sm1ke]

My car is already at the dealership so I can't look for these myself. Do these items you mention mean something different or scarier than the cracked cylinder head?

No, it's just a more obvious way to check for a coolant leak that originates at the cylinder head compared to fluctuating coolant levels.

 

[csb_1237]

Ours was a 2016.

So I feel I owe a bit of an update on how things went with the major repairs that we recently had done to our CX-9, which included the cylinder head replacement (as well as a replacement transmission). The CX has run like a top since we got it back, but I did notice a coolant-like smell in the car a few weeks ago. I monitored the coolant level in the overflow tank, and, sure enough, it was losing coolant. I took it to Ourisman Rockville Mazda this morning and my service advisor Phil was surprised to see me back, but said they'd figure out what was going on and, of course, there would be no charges for whatever it was (unless it wasn't related to the work they did before). They put me in a CX-30 loaner car, which was pretty nice, I guess. Anyway, turns out it was a coolant hose on the EGR system that was leaking and they put on a new clamp and cleaned it all up, so a really easy fix. Everything seems to be working fine now at just about 79,200 miles. I feel like we will keep the car for awhile now, having just poured almost $3500 into it!

 

[javierHere]

So a small update :
A week ago dealer called that my cx-9 is finally done and has a new engine. It only took them 2.5 months 😎
I took it home, and next day I noticed a smell of coolant and few drops of oil on the driveway.
I thought it’s a residual oil dripping or something.
following day I found a puddle of oil under the car.
took it back to the dealer this Thursday where they verified that the engine is leaking oil AND coolant. 🤬. and it doesn’t look good.
they said they won’t be able to actually look at it closer till Monday. I have a feeling another engine swap is in my future.

My CX-9 is having the same issue. Coolant leak.. cracked cylinder. Did you have to pay to have the engine replace? Can you advise me on how to get Mazda USA to pay for it. My car is 2017, with 93K miles.

 

[carshark]

Is there a computer savvy person that could create a ”poll“ for owners that have had the cracked cylinderhead.

Would be very interesting to know model year and milage.

 

[csb_1237]

My CX-9 is having the same issue. Coolant leak.. cracked cylinder. Did you have to pay to have the engine replace? Can you advise me on how to get Mazda USA to pay for it. My car is 2017, with 93K miles.

So, the head replacement is probably in order, though I believe the engine has to come out of the car for them to do the head, so it's pretty much a wash on labor to replace the head vs. replacing the engine. If the "just" do the head, they have to swap everything over onto your "old" engine block and that is a lot of work...seems easier just to do the engine swap, BUT only if MAZDA is paying, right?

Anyway, here I would say if you have a good Mazda dealer, with conscientious and patient service advisors/service managers, they may be able to get Mazda corporate to pay something towards the repair. In my case, I ended up paying about $2800 on a repair that would have cost close to $7000, which, while I was grumbling that I shouldn't have to pay to have a manufacturer defect on my vehicle repaired, it was better than nothing.

My CX-9 had 78K miles on it at the time, so they may not cover as much of the repair given the higher mileage on your CX-9, but I really don't know. It would help if you have meticulously maintained the vehicle and have detailed service records to provide to them, if they ask; (in my case they apparently asked the dealer to see their service records for my vehicle, but I do all my own maintenance (and keep meticulous records!!) and I offered to share my records with them, but they didn't ask for them. I did write Mazda corporate a "complaint" letter after it was all over and they called/e-mailed me and asked me what I wanted. I told them: 1) a little transparency about what the actual problem is (what is actually causing these heads to fail?) and 2) that they apply a consistent repair policy across the board, don't cover some repairs and not others...cover them all in full, regardless of the mileage, or decide on some pre-set percentage and let the dealers know what the policy is...and apply it consistently.

So after that they (Mazda) contacted the dealer to see how much I actually paid for the repair, and based on what the dealer told them, they decided they had paid "enough" and wouldn't pay me any more. Remember, I DID NOT ASK them for money!! They simply ignored my other requests. I may call them again sometime to close the loop and see if they are able to provide me with what I actually asked them. Meanwhile our car just passed 80K miles and other than an over sensitive TPMS that I have had to reset TWICE since we got our car back, we have had no other issues. Knock on the proverbial wood...🪵

 

[Super Upet]

There are a few threads regarding the 2.5 turbo coolant leak problem and ultimately having to replace the engine. What I'd like to know is there anything that can be inspected and possibly fixed with this issue before it gets to the point of actually needing a new engine?

Edit:
I updated the thread to include a poll now of who is and isn't having this issue.

If you've had this done, please comment on the model year, how many miles you had when it occurred, when you first noticed the issue, if Mazda covered the cost under warranty, and any other details.

Also those with higher miles and no issues let us know how many miles so far.

I am having this issue now at 53,300 miles. I had to file a claim with Mazda because my 5 yr warranty was up in Dec. 2022. My car was a lease and I purchased it when over financed by a credit union and thank goodness purchased a warranty. Mazda wants $3,500 to tear down the engine since my warranty requires inspection of the parts. I refuse to pay for a known issue which caused me to file a claim with Mazda Corp to cover the entire work done. It is going on two weeks now and they have not approved this.

 

[Super Upet]

There are a few threads regarding the 2.5 turbo coolant leak problem and ultimately having to replace the engine. What I'd like to know is there anything that can be inspected and possibly fixed with this issue before it gets to the point of actually needing a new engine?

Edit:
I updated the thread to include a poll now of who is and isn't having this issue.

If you've had this done, please comment on the model year, how many miles you had when it occurred, when you first noticed the issue, if Mazda covered the cost under warranty, and any other details.

Also those with higher miles and no issues let us know how many miles so far.

You could try the social media and media approach. The more public this lack of support becomes the more chances that Mazda will do something about it.

Here is an example of a somewhat successful media campaign for out of warranty repair: Cablegate: Toyota Agrees to Pay for Replacement as Investigation Continues

toyota cable corrosion - Google Search

I have the leak problem now at only 53,300 miles and my warranty ran out in Dec. 2022. I had to file a claim with Mazda to cover this in good will and going on two weeks now. I have been posting on all social media sites and even wrote on their wall on FB and finally got a response from them. I am getting ready to go to the media because they are well aware of two issues and even issues a Technical Service Bulletin on the collant leaks. I question why they didn't do a recall or why there isn't a class action lawsuit for this issue. It's rediculous they want you to pay for the repair knowing it's a manufacturing defect on their part! I have an extended warrante who wants to inspect the parts and the tear down is $3,500 which they won't cover. i refuse to pay anything out of my pocket for this. I am ready to contact the media to make this issue very public!

 

[Super Upet]

I am beyond upset with how Mazda is treating me regarding this issue the coolant leak I recently obtain. I was told that since my car shows no record of service with the dealership that they refuse to cover the issue. I advised them that my car has been serviced with a licensed mechanic and that no where does it state I am obligated to use their mechanics in order for them to take responsibility for fixing the coolant leak. I am feeling discriminated and as a Mazda owner should have the same treatment. I have 53,300 miles and my warranty expired on Dec. 2022. I have an extended warranty that wants to inspect the parts and require a tear down which is $3,500 and I refuse to pay any money out of my pocket for a known problem. I am also reading that 3rd party warranties are refusing to cover the parts that are defective so why should we have to pay out of our pockets? I am getting ready to go to the media and find an atty to see if a class action lawsuit is warranted for negligence on their part for failing to fix this defect in good faith vs making us pay.

 

[Silly Wabbit]

3rd party "warranty" is generally a nightmare to get them to pay out for high dollar repairs.

Is Mazda giving you issue for not providing service receipts from your licensed mechanic or just because it was serviced by your licensed mechanic?

 

[hollandog]

I have the leak problem now at only 53,300 miles and my warranty ran out in Dec. 2022. I had to file a claim with Mazda to cover this in good will and going on two weeks now. I have been posting on all social media sites and even wrote on their wall on FB and finally got a response from them. I am getting ready to go to the media because they are well aware of two issues and even issues a Technical Service Bulletin on the collant leaks. I question why they didn't do a recall or why there isn't a class action lawsuit for this issue. It's rediculous they want you to pay for the repair knowing it's a manufacturing defect on their part! I have an extended warrante who wants to inspect the parts and the tear down is $3,500 which they won't cover. i refuse to pay anything out of my pocket for this. I am ready to contact the media to make this issue very public!

I feel you and this is my first & last Mazda. I was bought into a reliable Japanese brand but got a time bomb. I emailed the corp and even the CEO about this situation but they gave me some bulls*** responses. I don't have the coolant leak "yet" but my infotainment has the spider crack that they refused to fix because obviously I'm out of warranty now at 63k miles.

 

[sm1ke]

3rd party "warranty" is generally a nightmare to get them to pay out for high dollar repairs.

Is Mazda giving you issue for not providing service receipts from your licensed mechanic or just because it was serviced by your licensed mechanic?

Sounds like Mazda is pushing back on an out-of-warranty goodwill repair because the car was not serviced by a Mazda dealership.

For warranty repairs, Mazda cannot deny coverage as long as service records and receipts are provided, no matter who performs the service. However, if the car is out of warranty, unfortunately they don't have to lift a finger. Blaming it on the car not being dealer-serviced is just a more convenient excuse for them as opposed to saying "we don't feel like it".

 

[Super Upet]

I feel you and this is my first & last Mazda. I was bought into a reliable Japanese brand but got a time bomb. I emailed the corp and even the CEO about this situation but they gave me some bulls*** responses. I don't have the coolant leak "yet" but my infotainment has the spider crack that they refused to fix because obviously I'm out of warranty now at 63k miles.Th

I feel you and this is my first & last Mazda. I was bought into a reliable Japanese brand but got a time bomb. I emailed the corp and even the CEO about this situation but they gave me some bulls*** responses. I don't have the coolant leak "yet" but my infotainment has the spider crack that they refused to fix because obviously I'm out of warranty now at 63k miles.

They extended the warranty for the cracked monitor from 5 ys to 7 here is the document Mazda put out.