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

[Jack Rabbit]

I agree that Mazda has to take responsibility for a design flaw. My own CX-9 (2018 just got a new cylinder head on the warranty) I think heat cycles is more significant than running over pot holes. My car has been used for shorter trips most of its life. Started to understand something was wrong around 50000 when it was idling rough. I understand that the companies that sell service contracts “refuses” to pay. They are trying to put pressure on Mazda to force them to take responsibility. Mazda most probably do not want to end up in a law suit that includes a warranty company as they have much better idea how common this problem is compared to consumers. Consumers only source for information is the TSB and forums like this. I’m sure the second hand value will be affected in the long run. Would I buy a 2016-2019 with 75000 miles? Hell no.

Yep...

Nobody wants to pay.
They both should cover it.

Mazda should step up even if it's over the warranty period and fix it since it was a major defect.

If you have an extended warranty, then the extended warranty companies should cover it as thats the whole reason you buy an extended warranty.

Technically both of them should pay to fix it...

While there have been posts of Mazda fixing some that were a few miles over the warranty period, there have been other posts where the customer had a fight on their hands to get it fixed.

And it sounds like the extended warranty companies have been atrocious for trying to deny coverage(but eventually fixing) or occassionally just outright denying the fix.

If this mazda engine fails and they dont fix it, i'll either go back to Ford reliable powertrains or maybe get a Hyundai with 10 year warranties.

Mazda is the GOAT that coulda been. Like that off-the-rails self-destructive sportsplayer that sabotages themselves , uses streoids, drugs, abuses/hits girlfreind/wife or commits some crime, Mazda can control it's destiny but doesn't.

It appears Mazda trys new things but at the customer expense.
Time will tell but it's ranking among the major manufacturers is a telling story. Theres a reason it's 22 while Hyundai has risen to 10.

If they are gonna try new things then they have got to get the improved reliabilty or offer 10 year PT warranties.

The next few years will show.
Will it continue innovation while improving reliabilty? Will it fix the defective cracked engines after warranty period expiry? Will it show it can be a top 10 contender or disappear in the annals of time?

And YES they're FUN to drive but not worth buying a new engine if it fails.

 

[yrwei52]

⋯
It appears Mazda trys new things but at the customer expense.
Time will tell but it's ranking among the major manufacturers is a telling story. Theres a reason it's 22 while Hyundai has risen to 10.

Yes, Mazda has been willing to try new innovations such as the rotary engine、the SkyActiv-G high-compression engine、adding the cylinder deactivation to a 4-cylinder engine、adding the turbo to a larger 2.5L I-4、and the SPCCI / SkyActiv-X “compression-ignition” gasoline engine, etc.. But the new innovation takes time to prove its durability. And the durability and reliability, especially the big items like engine and transmission, are very important to our consumers.

Which ranking (22 for the Mazda) are you referring to?

 

[sm1ke]

Mazda is the GOAT that coulda been. Like that off-the-rails self-destructive sportsplayer that sabotages themselves , uses streoids, drugs, abuses/hits girlfreind/wife or commits some crime, Mazda can control it's destiny but doesn't.

It appears Mazda trys new things but at the customer expense.
Time will tell but it's ranking among the major manufacturers is a telling story. Theres a reason it's 22 while Hyundai has risen to 10.

If they are gonna try new things then they have got to get the improved reliabilty or offer 10 year PT warranties.

The next few years will show.
Will it continue innovation while improving reliabilty? Will it fix the defective cracked engines after warranty period expiry? Will it show it can be a top 10 contender or disappear in the annals of time?

@Jack Rabbit, I will respectfully ask that you stay on topic. This is not a thread for bashing Mazda as a brand, and talk like this doesn't contribute anything to the discussion. Especially when you don't provide sources or context for your talking points. It's treading very closely to trolling at this point (IMO as a mod).

When I do a google search for "Mazda reliability", almost all of the results from the past three years show Mazda earning #1 to #5 spots depending on the website/publication (including Consumer Reports and J.D. Power).

 

[Muggs1]

If this mazda engine fails and they dont fix it, i'll either go back to Ford reliable powertrains or maybe get a Hyundai with 10 year warranties.

Mazda is the GOAT that coulda been. Like that off-the-rails self-destructive sportsplayer that sabotages themselves , uses streoids, drugs, abuses/hits girlfreind/wife or commits some crime, Mazda can control it's destiny but doesn't.

It appears Mazda trys new things but at the customer expense.
Time will tell but it's ranking among the major manufacturers is a telling story. Theres a reason it's 22 while Hyundai has risen to 10.

If they are gonna try new things then they have got to get the improved reliabilty or offer 10 year PT warranties.

The next few years will show.
Will it continue innovation while improving reliabilty? Will it fix the defective cracked engines after warranty period expiry? Will it show it can be a top 10 contender or disappear in the annals of time?

And YES they're FUN to drive but not worth buying a new engine if it fails.

It seems that you made a hobby in bashing Mazda. When you put Ford and reliable in the same sentence and you also mention Hyundai with their 10yr warranties, it shows me that you have no clue about the automotive industry. Ford's best reliable car, probably is the F150 which they put the most money into it, but they're SUV's suck. But then again, its a truck, Mazda does not have a truck. Hyundai offers 10yrs as a warranty because their entire lineup sucks and is plague with issues, from engine failures, fires, etc. You just need to google it and you will see them all over the place.

While I am not taking Mazda's part, when it comes to issues like this one, which is a big deal I think they fared WAY BETTER in terms of reliability compared with the two that you mentioned.

 

[Jack Rabbit]

A

@Jack Rabbit, I will respectfully ask that you stay on topic. This is not a thread for bashing Mazda as a brand, and talk like this doesn't contribute anything to the discussion. Especially when you don't provide sources or context for your talking points. It's treading very closely to trolling at this point (IMO as a mod).

When I do a google search for "Mazda reliability", almost all of the results from the past three years show Mazda earning #1 to #5 spots depending on the website/publication (including Consumer Reports and J.D. Power).

Fair enough. If you consider it bashing, so be it. While I like the Mazda and the way it drives, handling and safety features , the engine potential engine problem and having to drop another $7000 to $10,000 after warranty does not sit well for something that is/was a manufacturing problem. My Toyota, VW and multiple Ford engines lasted well into 14 years/200 k miles with no problems or codes, save an occassional water pump or sensor towards end of life. Just thjs week, I had to run to the mechanic because my mazda CX-5 codes and was worried it was the engine. Need the vehicle to run and go to work and it's a holiday week. Apparentley it's a throttle and other electronics failure. Said it's ok to drive for now but watch for it to code again. Then he'll have to see if it's the throttle and/or some electronics failure. Didnt need coding during holiday week.
Im taking a break from the board for awhile.

 

[Jack Rabbit]

It seems that you made a hobby in bashing Mazda. When you put Ford and reliable in the same sentence and you also mention Hyundai with their 10yr warranties, it shows me that you have no clue about the automotive industry. Ford's best reliable car, probably is the F150 which they put the most money into it, but they're SUV's suck. But then again, its a truck, Mazda does not have a truck. Hyundai offers 10yrs as a warranty because their entire lineup sucks and is plague with issues, from engine failures, fires, etc. You just need to google it and you will see them all over the place.

While I am not taking Mazda's part, when it comes to issues like this one, which is a big deal I think they fared WAY BETTER in terms of reliability compared with the two that you mentioned.

I also have noted the positives of the mazda in other threads/posts.

So im not allowed to post negative?

Thus engine thing is really upsetting as i purchase a vehciles to last 10 to 14 years and price it out over at least a 10 year period and you shouldnt have to drop an extra $7000 to $10000 Grande to fix a vehicle. Both my VW(bought used), Toyota and multiple Ford engines have lasted 14 years and over 200 k miles without any power-train failures or coding.

This will be my last post for awhile as apparently only positives posts are encouraged.

 

[Jack Rabbit]

Yes, Mazda has been willing to try new innovations such as the rotary engine、the SkyActiv-G high-compression engine、adding the cylinder deactivation to a 4-cylinder engine、adding the turbo to a larger 2.5L I-4、and the SPCCI / SkyActiv-X “compression-ignition” gasoline engine, etc.. But the new innovation takes time to prove its durability. And the durability and reliability, especially the big items like engine and transmission, are very important to our consumers.

Which ranking (22 for the Mazda) are you referring to?

Sales figures.
Top 10 includes Chevy, Ford, Toyota, Hyundai, etc. Mazda is only ranked 22 in sales.

 

[sm1ke]

Fair enough. If you consider it bashing, so be it. While I like the Mazda and the way it drives, handling and safety features , the engine potential engine problem and having to drop another $7000 to $10,000 after warranty does not sit well for something that is/was a manufacturing problem. My Toyota, VW and multiple Ford engines lasted well into 14 years/200 k miles with no problems or codes, save an occassional water pump or sensor towards end of life. Just thjs week, I had to run to the mechanic because my mazda CX-5 codes and was worried it was the engine. Need the vehicle to run and go to work and it's a holiday week. Apparentley it's a throttle and other electronics failure. Said it's ok to drive for now but watch for it to code again. Then he'll have to see if it's the throttle and/or some electronics failure. Didnt need coding during holiday week.
Im taking a break from the board for awhile.

Understand that while it's perfectly fine to take a cautious outlook on your Mazda, spreading FUD (fear, uncertainty, doubt) regarding the brand as a whole is not ok. This is in reference to the bolded text from the post I quoted. We are here to learn and share information, first and foremost.

I also have noted the positives of the mazda in other threads/posts.

So im not allowed to post negative?

Thus engine thing is really upsetting as i purchase a vehciles to last 10 to 14 years and price it out over at least a 10 year period and you shouldnt have to drop an extra $7000 to $10000 Grande to fix a vehicle. Both my VW(bought used), Toyota and multiple Ford engines have lasted 14 years and over 200 k miles without any power-train failures or coding.

This will be my last post for awhile as apparently only positives posts are encouraged.

You have been on these boards for a while, you know this is not the case.

VW, Toyota, and Ford vehicles all have some issues, and if you dug far enough I'm sure you'd find them. The fact that you never had issues with any of yours just means that you weren't one of the unlucky owners who did. Who knows, maybe your CX-5 will be the same and you'll never experience any major issues. I hope for that to be the case.

Sales figures.
Top 10 includes Chevy, Ford, Toyota, Hyundai, etc. Mazda is only ranked 22 in sales.

Mazda is a smaller manufacturer with a smaller piece of the pie. Probably fewer dealerships in the wild. Sales are only one piece of the picture. When it comes to reliability and general owner satisfaction, Mazda always ranks fairly high.

 

[yrwei52]

⋯
This will be my last post for awhile as apparently only positives posts are encouraged.

Don’t have to be your last post for awhile as honestly I’d be treated the same way like you before even though I believe I was giving my honest opinions helping members. But you can’t blame the mod or owner of the forum to be sided towards Mazda vehicles a bit. After all this’s a Mazda forum. As long as you don’t do personal attack, you should be fine and be able to say something you really want to say.

 

[Freedom55]

Your personal experience may vary but in 50 years of driving, I've had a few internal engine problems with new cars after only a couple of years. 1976 VW Rabbit worn out valve guides causing blue smoke after starting (there was a recall but I already had too much mileage). 1985 Plymouth Horizon 2.2L engine knock from day one engine was completely rebuilt. 1991 Chevy Lumina 3.1L V6 (company car) piston slap due to poor casting quality of block which was wearing out; depending at which factory the block was cast, not all engines were affected but a well documented case (engine was rebuilt with oversize pistons but soon the knock returned). 1997 Subaru Outback 2.5L piston slap due to rich fuel mixture when cold and too short piston skirts (dealer did nothing). Subaru had multiple engine problems after they redesigned the engine (oil consumption, blown head gasket, engine knock) I think I don't need to elaborate more!

Luckily in recent years no engine problems but a slew of other problems mostly with my previous vehicle a 2017.5 Nissan Murano and a 2004.5 VW Passat Wagon 4Motion. I drive very little now that I'm olde and I'm keeping my fingers crossed as my CX-5 it's the only vehicle I had that didn't need any warranty work so far! I have to admit that a few vehicles I've had needed only minor warranty work (2014 Nissan Murano, 2012 RAV4, 2010 Kia Rondo, 1995 Ford Contour).

 

[carshark]

jack Rabbit has expressed dissatisfaction with how Mazda is handling the Cars that is out of powertrain warranty. I can only agree with him, even if I was lucky and had it covered under the 5 year/60000 mile warranty. But the whole thing tarnish my image of Mazda as there is owners that have had to pay out of pocket when the failure was outside the warranty period. You can accept that if it was a 500$ part. But in this case it is the ENGINE. A repair will range from 5000 up to 12.000$. That is significant. Only if we “Mazda fans” express our dissatisfaction we will see a change.

 

[sm1ke]

jack Rabbit has expressed dissatisfaction with how Mazda is handling the Cars that is out of powertrain warranty. I can only agree with him, even if I was lucky and had it covered under the 5 year/60000 mile warranty. But the whole thing tarnish my image of Mazda as there is owners that have had to pay out of pocket when the failure was outside the warranty period. You can accept that if it was a 500$ part. But in this case it is the ENGINE. A repair will range from 5000 up to 12.000$. That is significant. Only if we “Mazda fans” express our dissatisfaction we will see a change.

I mean, that's pretty typical, isn't it? If its out of warranty, you're on the hook. Same goes for a TV, or a phone, an aquarium, etc. All we can do is report the issues as they arise, and if the company starts a recall to cover the engine replacement (or the NHTSA forces them to issue a recall), owners who were SOL can claim the cost of the repair after the fact. It's the same as every other manufacturer that's had issues like this with their powertrains.

Further, if your goal is to express your distaste towards Mazda and push them to make changes, owners should first be reporting issues to the dealer, then Mazda Corporate, followed by the BBB/CAMVAP and the NHTSA (for safety related issues). This is the process outlined by Mazda, and it's the best way to notify them of any concerning issues. More frequent reports correlates to a more widespread issue, which should result in faster action/resolution. I'm sure Mazda reps do visit our site occasionally, but this probably isn't the first place they'll go to follow up on things. There are other avenues that you can take if you feel that Mazda isn't being forthcoming, like media exposure (news outlets, blogs, FB groups, etc.), but for that you'll probably need credible sources and actual statistics to present.

Again, let's get back on topic please.

 

[Greg_J]

Again, let's get back on topic please.

Regarding the topic,
The mechanic from the videos I posted before seems to be very experienced and he was literally shocked when he started welding the crack. The thickness of aluminum in that area was around 2mm. As an example, he was comparing and showing some Chinese brand cylinder head he found in his workshop, and the thickness of the aluminum edge there was about 7mm, which is approx 3,5 thicker.
Finally, he was highly disappointed with the way how Mazda designed the new cylinder head, specifically in saving the cost of aluminum in that area.
His advice was to not leave this particular engine downtime for a long period, as hydraulic cranks (the area where cracks appear)can possibly get jammed and cause significant stress when the engine is starting again after a long downtime.

 

[yrwei52]

Regarding the topic,
The mechanic from the videos I posted before seems to be very experienced and he was literally shocked when he started welding the crack. The thickness of aluminum in that area was around 2mm. As an example, he was comparing and showing some Chinese brand cylinder head he found in his workshop, and the thickness of the aluminum edge there was about 7mm, which is approx 3,5 thicker.
Finally, he was highly disappointed with the way how Mazda designed the new cylinder head, specifically in saving the cost of aluminum in that area.
His advice was to not leave this particular engine downtime for a long period, as hydraulic cranks (the area where cracks appear)can possibly get jammed and cause significant stress when the engine is starting again after a long downtime.

Only 2 mm thick on an aluminum material? No wonder that weak area is prone to crack.

 

[Greg_J]

Only 2 mm thick on an aluminum material? No wonder that weak area is prone to crack.

Exactly!

 

[sm1ke]

Regarding the topic,
The mechanic from the videos I posted before seems to be very experienced and he was literally shocked when he started welding the crack. The thickness of aluminum in that area was around 2mm. As an example, he was comparing and showing some Chinese brand cylinder head he found in his workshop, and the thickness of the aluminum edge there was about 7mm, which is approx 3,5 thicker.
Finally, he was highly disappointed with the way how Mazda designed the new cylinder head, specifically in saving the cost of aluminum in that area.
His advice was to not leave this particular engine downtime for a long period, as hydraulic cranks (the area where cracks appear)can possibly get jammed and cause significant stress when the engine is starting again after a long downtime.

Just for reference, here is the video posted again. It was the second video in the series, and it's about 16 minutes in. For anyone who can't read or understand Russian, turn on subtitles/closed captions in the video, choose auto-translate, then choose English as the language.

Mazda 3 Skyactiv-G 2.5 ******* * *******. ***** 2, ******

**** ******, ******* ****** ******** * ******* * ******. *** ********* ******* ***** ********* Mazda 3 * ****** BP * ******* Skyactiv-G ******* 2.5*** ******...

www.youtube.com

 

[concept]

It's easy to second-guess Mazda engineers, but much harder to have the knowledge of all the specifications of every component involved. Engine engineers frequently need to utilize Finite Element Analysis to determine component thickness. Take a simple Grade 8 (6mm) bolt that is used in automotive applications. Few non-engineers would realize just how strong that bolt is in tension.

 

[yrwei52]

It's easy to second-guess Mazda engineers, but much harder to have the knowledge of all the specifications of every component involved. Engine engineers frequently need to utilize Finite Element Analysis to determine component thickness. Take a simple Grade 8 (6mm) bolt that is used in automotive applications. Few non-engineers would realize just how strong that bolt is in tension.

Yes. But we as non-engine design engineers can see the 2mm thickness is a flaw easily by the end result. The area definitely has been weakened by the CD modification on cylinder head, hence we see the crack happens which we don’t see on original head with non-CD 2.5L NA.

 

[Mulligan]

What to make of there being only 2mm of material at the location of the crack? I have a couple ideas—barely more than guesses, but informed by a dusting of logic, experience, and common sense, I hope.

Guess 1: Mazda used the occasion of revising the cylinder head for CD as an opportunity to implement a bit of ill-advised "value engineering" whereby they made other changes to the head--unrelated directly to CD technology--to shave off a gram or two of aluminum. This leads me to blame the bean counters who leaned on the engineers, not cylinder deactivation technology per se, for the cylinder head crack problem.

Guess 2: Given that the crack is at the cylinder 3 side of the boundary between a deactivating cylinder (4) and a non-deactivating cylinder (3), it’s not so much the extra bits and bobs supporting cylinder deactivation that caused the crack as a discontinuity between a CD and a non-CD cylinder. The discontinuity that comes to mind isn’t the change in the shape or thickness of the head, but rather the temperature difference between cylinders 3 and 4 that occurs when cylinder 4 is deactivated. Temperature differences cause different amounts of expansion, which causes stress, which causes a crack.

It would be interesting to find out if the aluminum at the HSA cavities in the pre-CD heads is 2 mm thick. If it’s thicker, that would support my first guess. If it is the same thickness as the corresponding part of the CD heads, that would support my second guess.

I doubt we'll ever know. I looked for photos of a pre-CD head showing the area and came up empty, but unless there's something drastically different about the casting of the heads, even a good picture probably wouldn't tell us much.

Note: Since the YouTube video from which the second picture below is taken was filmed in a mirror, I've flipped the image to make the head appear as it would if you were looking directly at it.

 

[yrwei52]

What to make of there being only 2mm of material at the location of the crack? I have a couple ideas—barely more than guesses, but informed by a dusting of logic, experience, and common sense, I hope.

Guess 1: Mazda used the occasion of revising the cylinder head for CD as an opportunity to implement a bit of ill-advised "value engineering" whereby they made other changes to the head--unrelated directly to CD technology--to shave off a gram or two of aluminum. This leads me to blame the bean counters who leaned on the engineers, not cylinder deactivation technology per se, for the cylinder head crack problem.

Guess 2: Given that the crack is at the cylinder 3 side of the boundary between a deactivating cylinder (4) and a non-deactivating cylinder (3), it’s not so much the extra bits and bobs supporting cylinder deactivation that caused the crack as a discontinuity between a CD and a non-CD cylinder. The discontinuity that comes to mind isn’t the change in the shape or thickness of the head, but rather the temperature difference between cylinders 3 and 4 that occurs when cylinder 4 is deactivated. Temperature differences cause different amounts of expansion, which causes stress, which causes a crack.

It would be interesting to find out if the aluminum at the HSA cavities in the pre-CD heads is 2 mm thick. If it’s thicker, that would support my first guess. If it is the same thickness as the corresponding part of the CD heads, that would support my second guess.

I doubt we'll ever know. I looked for photos of a pre-CD head showing the area and came up empty, but unless there's something drastically different about the casting of the heads, even a good picture probably wouldn't tell us much.

Note: Since the YouTube video from which the second picture below was taken was filmed in a mirror, I've flipped the image to make the head appear as it would if you were looking directly at it.

I personally would believe what happened is your second guess. Mazda has already made the head as light as possible from its original design, the manager in charge should be smart enough denying any ideas from his/her engineers of shaving even more aluminum weight.

Yes temperature differences between activated and deactivated cylinders has always been the big problems for cylinder deactivation system. Some company’s such as Chrysler chose to alternating cylinders for deactivation to even out the temperature differences which cause different amounts of expansion and stress to each cylinder.

And I always suspect the bigger switchable HLA (hydraulic lift adjuster) cavities for cylinder #1 and #4 in the CD head are bigger than original head, hence it may contribute thinner walls around the area.