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

[CX5Nut]

I just finished reading this entire thread. It's very informative.

ADMIN / MODERATOR - Perhaps this thread should be pinned? What do you think? In the spirit of putting a significant issue front and center, it would be helpful/nice/informative if this was pinned.

I'm looking to buy a new 2023 CX-5 NA. However, after researching it (thanks to this forum and several other online resources), I'm deeply concerned about the cracked head problem. Thus, I'm going to start researching other compact SUVs. I'm not sure what I'll find (I may come back to the CX-5... who knows), but at this point I want to be more comfortable before I drop $40,000 on my next car.

Since this issue may become more of a problem as time goes on and affect more owners, pinning may be a good idea.

We are seriously considering replacing our 2018 CX5 once the powertrain warrantee is up but can't seem to find one with the same style and drive as our CX5. If you find something, please let us all know!

 

[sm1ke]

If/when an official TSB is issued for this specific problem, we will consider creating a sticky thread for it to make the solution and any useful reference documentation easy to find.

 

[mkristo2]

Good to know. Will be interested to see going forward how many on this board end up having an issue. Hopefully none!

My 2019 CX-5 with 30K miles started smelling of burning oil. Dealer diagnosed cracked cylinder head and repaired under warranty/ gave me loaner for 2 weeks while waiting on parts. When asked if the repaired part will fail again in 30,000 miles , dealer said Mazda has redesigned the faulty part . ( does anyone know about that? Credible?)

 

[CX5Nut]

My 2019 CX-5 with 30K miles started smelling of burning oil. Dealer diagnosed cracked cylinder head and repaired under warranty/ gave me loaner for 2 weeks while waiting on parts. When asked if the repaired part will fail again in 30,000 miles , dealer said Mazda has redesigned the faulty part . ( does anyone know about that? Credible?)

I would hope they did redesign the head but my understanding is that no one (except Mazda) knows for sure.

 

[edmaz]

.... dealer said Mazda has redesigned the faulty part . ( does anyone know about that? Credible?)

The three stories making the rounds are: 1) mis-designed head corrected with a new part version; 2) manufacturing defect, commonly referred to as 'a bad run of castings'; and 3) exhaust manifold nuts overtorqued at the factory.

There's been no proof as to which of the above is the actual cause, that I'm aware of anyway. Mazda did admit in print that their turbo heads have been revised due to design flaws, but nothing like that so far for the NA/CD heads. So unless Mazda provides an official confirmation in print, or some other highly credible evidence shows up, no one outside of the Mazda inner circle will know the answer to this question.

 

[BTR]

My 2019 CX-5 with 30K miles started smelling of burning oil. Dealer diagnosed cracked cylinder head and repaired under warranty/ gave me loaner for 2 weeks while waiting on parts. When asked if the repaired part will fail again in 30,000 miles, dealer said Mazda has redesigned the faulty part. (Does anyone know about that? Credible?).

@mkristo2 - Do you have the post-repair printout? If so, please post it. If we can see the part numbers, then we can begin to (maybe) figure out if the head has, or hasn't, been redesigned.

 

[edmaz]

@mkristo2 - Do you have the post-repair printout? If so, please post it. If we can see the part numbers, then we can begin to (maybe) figure out if the head has, or hasn't, been redesigned.

The replacement head that Mazda sends does have a new part number, which is PYY4-10-SJ0. However, that number actually represents the 'loaded' head containing much of the valve train components, and has a description of 'Head Set, Cylinder'. And they haven't written anything about the head being updated, so the part number alone is not going to help figure anything out.

What might actually be very helpful though would be to find pictures of the new head, particularly the upper back side, where the damage always occurs. Any significant difference at the back of the head, between the new head and the original one would basically confirm that a redesign was in fact done. So far there have been no pictures of this replacement NA head to be found on the online parts sites, just those stupid drawings instead.

I've kicked around the idea of asking at the Mazda parts counter to take a look at this new head (and then take a few pics as well), assuming they happen to have one available in stock. Unfortunately, I never get any warm vibes when I buy oil filters from them, and I've come to understand that they're not at all interested in carrying on any conversation with a DIYer customer, related to current Mazda vehicle issues.

So I've given up asking them anything, and I suspect they would find an excuse to reject my request, even if they did have one of those heads in stock. Perhaps someone else, who has a good relationship with someone working at Mazda, might provide a major service to others here by taking some pics of the back of one of these replacement NA heads.

 

[BTR]

@edmaz - Understood.

I like your proposed approach to answering the question (same/different head?). Am I correct in recalling that... somewhere in this thread... there's a a picture of the back of an "old" head? And/or are there pictures somewhere else in the forum? If we can get a picture of the back of an "old" head, then we're halfway there.

Re pictures of a "new" head, I'll see if I can execute your approach. No guarantees, but I'll give it a shot.

 

[edmaz]

... Am I correct in recalling that... somewhere in this thread... there's a a picture of the back of an "old" head? ...

Here's a snapshot from the set of vids of a couple of cracked NA heads taken by a Russian mechanic, which were posted somewhere in this thread.

The particular areas of interest are marked in green, directly above the exhaust manifold studs, which is where the cracking has been reported. However, if they did modify the head by beefing it up, then the entire area marked in red might look different as well. And that upper section of the back of the head is also accessible on our vehicles (after removing the heat shield), for additional close-up pics if necessary.

Good luck to you, or anyone else who might want to try getting a look at that replacement head!

 

[BTR]

@edmaz - Perfect! Thanks! That's the exact pic I was thinking about (because it shows the bracing between cylinders 1 and 2).

 

[BTR]

I spoke with a Mazda dealer here. I started by asking the parts guy about the 2018-2021 heads, the 2022 head, and the 2023 head on the 2.5L SKYACTIV NA w CD. He was aware of the head cracks, but didn't know if a "new/different" head was being used on the 2023s. He said he'd speak with the shop foreman. Upon returning from speaking with the shop foreman, he stated quote-unquote:

"We've had a ton of these come in (for repair). There was a casting problem that made the aluminum thin. It caused oil leaks in the NA engines. The head was fixed in 2021. We haven't had any (head cracks) in 2022s or 2023s."

Sooooo, based on this, has anyone here heard of a head crack in a 2022 or 2023?

 

[SimpleCanuck]

I spoke with a Mazda dealer here. I started by asking the parts guy about the 2018-2021 heads, the 2022 head, and the 2023 head on the 2.5L SKYACTIV NA w CD. He was aware of the head cracks, but didn't know if a "new/different" head was being used on the 2023s. He said he'd speak with the shop foreman. Upon returning from speaking with the shop foreman, he stated quote-unquote:

"We've had a ton of these come in (for repair). There was a casting problem that made the aluminum thin. It caused oil leaks in the NA engines. The head was fixed in 2021. We haven't had any (head cracks) in 2022s or 2023s."

Sooooo, based on this, has anyone here heard of a head crack in a 2022 or 2023?

It's too soon to tell at this point as it seems to happen after a few years and around 30-40K miles.

My '22 with CD just hit 10,000 miles and no issues. But again, too soon to know for sure.

 

[edmaz]

... There was a casting problem that made the aluminum thin. .... The head was fixed in 2021. ...

The resolution to a casting problem would be fixing the casting problem, not fixing the head. So unless you had additional discussion beyond this which clarified what he said, it didn't answer your question of a new/redesigned head.

 

[BTR]

@edmaz - My inference... based on the way the parts guy spoke... was that the casting problem (that made the heads thin) was fixed in 2021. Granted, he didn't explicitly state that the head had been redesigned. However, the totality of what he said and the way he said it, led me to believe the "thin casting" problem had been fixed such that subsequent to 2021, the heads no longer have thin aluminum.

But, but, but... I appreciate your skepticism. I too remain somewhat skeptical. What I'd really like to see... in person, hands on, with a micrometer... is a head that's currently in use.

 

[edmaz]

@edmaz - My inference... based on the way the parts guy spoke... was that the casting problem (that made the heads thin) was fixed in 2021. Granted, he didn't explicitly state that the head had been redesigned. However, the totality of what he said and the way he said it, led me to believe the "thin casting" problem had been fixed such that subsequent to 2021, the heads no longer have thin aluminum. ...

I don't like to spend time rehashing things I've already said, but if the root cause of these NA cracked heads was (using his exact words), a casting problem that made the aluminum thin, then that must mean the manufacturing process didn't completely fill the mold. And the flip side of that would be the very great majority of heads which were correctly cast, and have no issues.

Now I'll be as conciliatory as possible by speculating and conceding it's possible that the original design was in some way making it difficult for the liquid aluminum to flow properly into every part of the mold, 100% of the time. If that was in fact the case, and they changed the mold to eliminate that situation, then IMO it really should have been described as a head design issue, instead of a casting problem. Part of the required engineering process would be a confirmation that the design of the mold will work properly with the casting process - every time. The same basic stuff that's been happening for well over a century.

In any case, I agree with you about still needing to see the new head, in order to try getting past all of the word games.

 

[p38cyq]

@CX5Nut : to answer your question : this is not very common.
Here in Europe, very few cases are documented (as per the UK end German forums).
Bought my first 2.5L NA with CD in 2017, and a 2022 (same config), had no problems.
My dealer isn't even aware of this subject.

 

[yrwei52]

@CX5Nut : to answer your question : this is not very common.
Here in Europe, very few cases are documented (as per the UK end German forums).
Bought my first 2.5L NA with CD in 2017, and a 2022 (same config), had no problems.
My dealer isn't even aware of this subject.

At least in the US, the 2.5L NA with CD is only available starting from the 2018 MY CX-5.

 

[concept]

Often, a "casting problem" is one or more voids in the material. I used to work for a company that had stainless steel brake rotors made by investment casting. To check for voids, I bought an ultrasonic tester. We would check each rotor before sending it out for machining.

 

[ibehomebrew]

2018 cx5 6 months out of warranty bought it in 2017 Mazda dealer says the cracked cylinder head is not covered and has no recalls on it. NHTSA site had scores of people with the same problem my money is on casting problems seems pretty rare for a 5-year-old head to crack everyone I have talked to had not seen it before. Really wish someone with time and money could sue them to force the issues.

 

[yrwei52]

2018 cx5 6 months out of warranty bought it in 2017 Mazda dealer says the cracked cylinder head is not covered and has no recalls on it. NHTSA site had scores of people with the same problem my money is on casting problems seems pretty rare for a 5-year-old head to crack everyone I have talked to had not seen it before. Really wish someone with time and money could sue them to force the issues.

I can feel your pain for a such major engine issue without warranty. The 2mm wall at the back of the head is prone to crack since it’s too thin. A YouTube video from Russia / Ukraine has clearly showed the area cracked on his 2.5L NA with cylinder deactivation. IMO this’s a design problem, not a casting problem.

But I have to ask you when did you get your 2018 CX-5? If you got it in 2017, hence you’re out of powertrain warranty as you stated, that doesn’t make sense. The 2018 CX-5 came out in Feb. 2018, you simply can’t get one in 2017! Ask how I know, as I wanted a 2018 CX-5 and not until late Feb. 2018 Mazda finally started to deliver them. I didn’t get it then as I found out Mazda had added the cylinder deactivation without too much publicity.