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

[Jack Rabbit]

If it's a bolt torque issue, would be nice if they issued a recall to have the bolts checked and re-torqued correctly, it that is possible.

If the bolts were overtorqued, it's too late as the damage been done and on those overtorqued will have unseen micro-cracks in the cylinder head. Just a matter of time before micro-cracks subjected to hot pressurized engine expand and continually become worse.

Just a waiting game. They'll fix the ones that fail during warranty period. Anyone else is out of Luck.

It might be worth it to pay for a specialized test (by a third party) to verify micro-cracks in cylinder head before the warranty expiration and then request Mazda fix it. I am considering having this specialized testing before the warranty expires.

Edit: maybe in the future the governments can mandate engines go though spot check engine testing for micro-cracks. Especially since vehicles are high priced items.

 

[CX5Nut]

If the bolts were overtorqued, it's too late as the damage been done and on those overtorqued will have unseen micro-cracks in the cylinder head. Just a matter of time before micro-cracks subjected to hot pressurized engine expand and continually become worse.

Just a waiting game. They'll fix the ones that fail during warranty period. Anyone else is out of Luck.

It might be worth it to pay for a specialized test (by a third party) to verify micro-cracks in cylinder head before the warranty expiration and then request Mazda fix it. I am considering having this specialized testing before the warranty expires.

Edit: maybe in the future the governments can mandate engines go though spot check engine testing for micro-cracks. Especially since vehicles are high priced items.

Our engine warrantee on our 2018 expires summer 2023. Your idea of having a third party check now for micro-cracks is an interesting one! Mazda should lengthen the warrantee on this issue past 5 years since it's a factory defect and not normal wear and tear.

 

[hw4ng3r]

I wonder if it is a ticking time bomb or if you're in the clear after lets say 50k considering how "early" the leaks came up in the life of the engine.

 

[hw4ng3r]

For completeness sakes/record:

2018 CX5 GT, purchased brand new. Odo at the time I noticed the burnt oil smell in the cabin: ~35000 km/~22000 miles. All work and parts were covered under the Powertrain Warranty.

Refer to this post for Chain of events

Location: Toronto, Ontario, Canada
Problem diagnosed/parts ordered on Dec 13, 2021
Parts arrived Aug 17, 2022

Drove it around until the parts arrived. I guess the slow leak was not catastrophic. Only had the "oil level low" indicator kick on once in the 8 months of waiting for parts. Just had to put up with stench of burn oil fumes in the cabin when driving around with fresh air coming in. This was a major headache in the winter especially when you have to use the front windshield defrost.

Car dropped off at Mazda on Aug 22, 2022
Car returned Aug 29, 2022

Direct from work order:
A REPORT ON OIL LEAKING FROM ENGINE (HEAD AREA)
CAUSE: REPLACED LEAKING CYLINDER HEAD. BULLETIN SA-031/21
B0401FRX CYLINDER HEAD (WITHOUT ENGINE VALVE R&R), R&R

Parts:
1 PYY4-10-SJ0 HEAD SET, C
1 PY01-10-271 GASKET, CYL
5 5555-CL-001R ANTI-FREEZ
1 PE01-13-655 GASKET, THR
1 PE01-15-165 GASKET, W. P
1 PYFA-15-592A O-RING
1 KL2F-50-EK1-BB COVER (R), T
1 PE02-18-T41 RING, 'O'
2 9956-21-200 GASKET
5 PY01-13-111 GASKET, INL
1 PE01-15-287 RING, 'O' -W
1 PYMM-13-290A PIPE, FUEL
1 PE01-10-673 RING, 'O'
1 PE01-12-257 RING, 'O'
2 9994-61-000 NUT
1 PE23-40-305 GASKET
1 PY01-14-342 GASKET, OIL
1 PE01-13-555 RUBBER. SEA
1 PE01-18-T41 RING, 'O'
4 PYFA-13-252 GROMMET
1 PE01-20-ZF2 RING, 'O'
1 PY01-10-2C8 GASKET
1 PYFA-15-591A O-RING
1 PYFA-15-159A GASKET, WTR
1 0000-77-1217-TB SEALANT SI
1 PYFA-10-235 GASKET, HEA
1 PYFA-18-G00A PUMP, VACUU
1 1WPE-14-302 CARTRIDGE,
5 5555-EG-001R ENGINE OIL
5 5555-CL-001R ANTI-FREEZ
1 PE01-10-602 SEAL, OIL
4 PY01-13-252 GROMMET
4 PYFA-13-253 O-RING

Labour: not stated; N/C
Cost: N/C

 

[Jack Rabbit]

For completeness sakes/record:

2018 CX5 GT, purchased brand new. Odo at the time I noticed the burnt oil smell in the cabin: ~35000 km/~22000 miles. All work and parts were covered under the Powertrain Warranty.

Refer to this post for chain of events Chain of events

Location: Toronto, Ontario, Canada
Problem diagnosed/parts ordered on Dec 13, 2021
Parts arrived Aug 17, 2022

Car dropped off at Mazda on Aug 22, 2022
Car returned Aug 29, 2022

Direct from work order:
A REPORT ON OIL LEAKING FROM ENGINE (HEAD AREA)
CAUSE: REPLACED LEAKING CYLINDER HEAD. BULLETIN SA-031/21
B0401FRX CYLINDER HEAD (WITHOUT ENGINE VALVE R&R), R&R

Parts:
1 PYY4-10-SJ0 HEAD SET, C
1 PY01-10-271 GASKET, CYL
5 5555-CL-001R ANTI-FREEZ
1 PE01-13-655 GASKET, THR
1 PE01-15-165 GASKET, W. P
1 PYFA-15-592A O-RING
1 KL2F-50-EK1-BB COVER (R), T
1 PE02-18-T41 RING, 'O'
2 9956-21-200 GASKET
5 PY01-13-111 GASKET, INL
1 PE01-15-287 RING, 'O' -W
1 PYMM-13-290A PIPE, FUEL
1 PE01-10-673 RING, 'O'
1 PE01-12-257 RING, 'O'
2 9994-61-000 NUT
1 PE23-40-305 GASKET
1 PY01-14-342 GASKET, OIL
1 PE01-13-555 RUBBER. SEA
1 PE01-18-T41 RING, 'O'
4 PYFA-13-252 GROMMET
1 PE01-20-ZF2 RING, 'O'
1 PY01-10-2C8 GASKET
1 PYFA-15-591A O-RING
1 PYFA-15-159A GASKET, WTR
1 0000-77-1217-TB SEALANT SI
1 PYFA-10-235 GASKET, HEA
1 PYFA-18-G00A PUMP, VACUU
1 1WPE-14-302 CARTRIDGE,
5 5555-EG-001R ENGINE OIL
5 5555-CL-001R ANTI-FREEZ
1 PE01-10-602 SEAL, OIL
4 PY01-13-252 GROMMET
4 PYFA-13-253 O-RING

Labour: not stated; N/C
Cost: N/C

Thanks for posting.

Luckily I got a 2018 cpo with 7 year/100,000 miles PTO warranty.
So have time to see how it plays out.

Additionally will be having Blackstone UOA at least once per year and maybe an engine ultrasound(hope to find a auto lab/auto test business close to me) to detect micro-cracks prior to the warranty end.

My suggestions is for anyone with a CX5, CX9, or mazda 6 to do the same as far as testing goes. If possible, buy a cpo for the extended warranty.

Lastly, the mazdas seem to have one heck of a safety ratings and based on some of members posting here that have walked away from accidents, even if one has to buy a new engine at $7000, small price to pay for a car that prevents life debilitating injury and death.

My next vehicle will be another mazda, or a ford maverick, or some other hybrid/electric truck provided it's safety ratings are near the mazdas.

 

[hw4ng3r]

Thanks for posting.

Luckily I got a 2018 cpo with 7 year/100,000 miles PTO warranty.
So have time to see how it plays out.

Additionally will be having Blackstone UOA at least once per year and maybe an engine ultrasound(hope to find a auto lab/auto test business close to me) to detect micro-cracks prior to the warranty end.

My suggestions is for anyone with a CX5, CX9, or mazda 6 to do the same as far as testing goes. If possible, buy a cpo for the extended warranty.

Lastly, the mazdas seem to have one heck of a safety ratings and based on some of members posting here that have walked away from accidents, even if one has to buy a new engine at $7000, small price to pay for a car that prevents life debilitating injury and death.

My next vehicle will be another mazda, or a ford maverick, or some other hybrid/electric truck provided it's safety ratings are near the mazdas.

I have nothing against the CX-5. It's been great up to this point. Only other complaint I have would be the rear brake rotors, they did not hold up well in the 3.5 years I've had it; no issues on the fronts.

I'm only one of three 2.5L NA CD motors with this issue at a dealership that is the 2nd largest Mazda dealer by volume sold in Canada (I do trust the service and my sales guy as I've seen some figures/info they probably shouldn't be showing me).

I've decided to move on from the CX-5 (thank's to COVID turning the used car industry upside down) to a 2022 CX-9 GT (my god I hope they figured out the coolant leak issues in the 2.5T, because if I get thrown in to that, this may be the last Mazda for a while).

 

[Jack Rabbit]

I have nothing against the CX-5. It's been great up to this point. Only other complaint I have would be the rear brake rotors, they did not hold up well in the 3.5 years I've had it; no issues on the fronts.

I'm only one of three 2.5L NA CD motors with this issue at a dealership that is the 2nd largest Mazda dealer by volume sold in Canada (I do trust the service and my sales guy as I've seen some figures/info they probably shouldn't be showing me).

I've decided to move on from the CX-5 (thank's to COVID turning the used car industry upside down) to a 2022 CX-9 GT (my god I hope they figured out the coolant leak issues in the 2.5T, because if I get thrown in to that, this may be the last Mazda for a while).

You should be safe. At the points they redesigned the cylinder head for warranty repairs, you would think that all vehicles manufactured afterwards would include the redesigned heads.

 

[edmaz]

... and maybe an engine ultrasound(hope to find a auto lab/auto test business close to me) to detect micro-cracks prior to the warranty end. ...

First off, a disclaimer that I don't have any expertise in the technology of checking an object for micro-cracks. Nevertheless, I'm somewhat doubtful if that type of testing can be done when the head is attached to the block. And it would be even more difficult in this case, given that the initial cracking is likely to exist only at the inside surface where the head meets the gasket, near the specific rear head bolt hole as shown in the TSB.

But if it is possible to do such testing with a high degree of confidence, are you expecting that Mazda would accept such a test result, and replace the head based on that alone, where no coolant is being lost? Or would you just plan to sell it if the test result indicated cracking?

Not saying this is a bad idea in concept, just wondering if it's physically doable, and what the value of the test result would be, if it is possible to do.

 

[Jack Rabbit]

First off, a disclaimer that I don't have any expertise in the technology of checking an object for micro-cracks. Nevertheless, I'm somewhat doubtful if that type of testing can be done when the head is attached to the block. And it would be even more difficult in this case, given that the initial cracking is likely to exist only at the inside surface where the head meets the gasket, near the specific rear head bolt hole as shown in the TSB.

But if it is possible to do such testing with a high degree of confidence, are you expecting that Mazda would accept such a test result, and replace the head based on that alone, where no coolant is being lost? Or would you just plan to sell it if the test result indicated cracking?

Not saying this is a bad idea in concept, just wondering if it's physically doable, and what the value of the test result would be, if it is possible to do.

If it is possible( based on websites sources, It sounded as if it may be done without engine removal but would need to actually check via phone conversation), then the value of the test would be to show that the head was cracked prior to warranty expiration and was defective. Even if they refuse to fix at that time and the micro-cracks expand and coolant leaks another year or two after the warranty, it would at least be on file so a lawsuit could be filed at later date. Or one could decide to file a lawsuit before warranty is expired(or short time thereafter up to 2 years from mazda denial to fix) under the Magnuson/Moss law to effecuate engine replacement.

So there may be some other ways to see if micro-cracks exist but they may be more intrusive and maybe even damaging( therefore am hoping ultrasound is a possibility)

Lastly most warranties on products(including cars) insure products free of defects in materials and workmanship for a period of time. A defect is a defect and they can't put restrictions (f.i. saying well it didnt leak yet)

A defect is a defect.
Imagine if Toyota argued (well the accelerate didnt stick yet?) Or a dam builder said(well the dam hasn't leaked yet even though they used substandard concrete)

At the points your putting such specific restrictions on a warranty then is it a warranty?

 

[edmaz]

I'm no fan of lawsuits, but it sounds like you would be ok with all of the BS that goes with that process. And I suppose it's possible that a test result like that might be of value in a court case.

And definitely post back if you find someone who is confident this test will produce a valid result on an installed head, and would do it for a reasonable price.

 

[Jack Rabbit]

I'm no fan of lawsuits, but it sounds like you would be ok with all of the BS that goes with that process. And I suppose it's possible that a test result like that might be of value in a court case.

And definitely post back if you find someone who is confident this test will produce a valid result on an installed head, and would do it for a reasonable price.

Likewise

Usually only the lawyers win.

It's a cost-benefit decision.

If they'll fix based on the test(hopefully not too expensive) then good to go..

If not then need to decide if worth it to get a New engine or reman engine installed(at your expense), or proceed with lawsuit or wait til your engine blows up.
While not illegal, it's shady and unethical to sell/trade a car once aware a problem exists. Leaves someone else holding the bag.

 

[CX5Nut]

What I really don't understand is how this is not a safety issue that would require a recall. Hot oil dripping on a hot engine as you drive could cause an engine fire, no?

 

[181962]

What I really don't understand is how this is not a safety issue that would require a recall. Hot oil dripping on a hot engine as you drive could cause an engine fire, no?

NHTSA initiates safety recalls based on incidents, not speculations. If there are not sufficient incidents of a particular model catching fire then fuggetaboutit.

 

[yrwei52]

NHTSA initiates safety recalls based on incidents, not speculations. If there are not sufficient incidents of a particular model catching fire then fuggetaboutit.

I disagree. How many incidents caused by the fallen rocker arms on those 2.5L with the cylinder deactivation? And how many incidents caused by the failed LED DRLs on the 2016 CX-5’s? Both of them triggered a safety recall. So just report the oil leak problem to the NHTSA. More complaints, more likely to get a recall.

 

[sm1ke]

I think its based on number of incidents and the information gathered from those reported incidents. For instance, with the rocker arms, maybe they were able to recreate the issue consistently enough that they determined a recall was necessary, while the cylinder head cracking issue is too sporadic or a clear cause of the issue is not known yet.

Manufacturers can also issue recalls on their own. Hyundai/KIA have issued quite a few fire risk recalls over the past few years, even though there have been very, very few actual reports of fires.

 

[181962]

I disagree. How many incidents caused by the fallen rocker arms on those 2.5L with the cylinder deactivation? And how many incidents caused by the failed LED DRLs on the 2016 CX-5’s? Both of them triggered a safety recall. So just report the oil leak problem to the NHTSA. More complaints, more likely to get a recall.

My lack of knowledge on number of incidents resulting in previous recalls doesn't matter. You can report oil leaks to the NHTSA until you are blue in the face, but if you are not reporting an incident that resulted in an actual safety threat, such as an actual engine fire, it's going nowhere. Limping or stalling from a fallen rocker arm or a failed DRL (as much as one might question it's usefulness) represent actual safety risks.

There are about 275 million registered vehicles in the US with an average age of 12+ years. A million or more of those may be leaking oil and yet engine fires are rare, rarer still with the later model vehicles., EVs excepted. There seems to be a rise in EVs spontaneously combusting from batteries overheating.

 

[Jack Rabbit]

My lack of knowledge on number of incidents resulting in previous recalls doesn't matter. You can report oil leaks to the NHTSA until you are blue in the face, but if you are not reporting an incident that resulted in an actual safety threat, such as an actual engine fire, it's going nowhere. Limping or stalling from a fallen rocker arm or a failed DRL (as much as one might question it's usefulness) represent actual safety risks.

There are about 275 million registered vehicles in the US with an average age of 12+ years. A million or more of those may be leaking oil and yet engine fires are rare, rarer still with the later model vehicles., EVs excepted. There seems to be a rise in EVs spontaneously combusting from batteries overheating.

Those who need to report are those who
have the coolant leak (unbeknownst to them) which widened to such a point that the engine overheated and the driver was on a highway and had to limp to the shoulder in dangerous traffic and await tow.

Or those who the engine was reaching failure and stalled on the highway. And then was towed home.

The problem is too many people try to limp these things home(and ruin the engine if it wasnt already) then dont know or can't be bothered to report these things to the NHTSA.

I didnt know about the NHTSA until 2010 with Toyota fiasco and most people are oblivious.

So the few percentage that are in safety situations most likely never report.

While the chances of that many mazda owners having this issue lead to car stopping/limping on the highway is low, it only takes one major accident with a 10 car pileup to bring these things to light, maybe.

Still reporting the engine/coolant issue will help rally the numbers so the NHTSA can seen how extensive the issue might be.

 

[mkristo2]

So I have started to see reports of cracked cylinder heads on CX5s (2018-2019) resulting in significant oil leaks. The cars have only ~25K miles on them!
What's this all about? How many here have had this happen? Time to sell our CX5 before it happens?

My 2019 cx5 with 2.5L engine , 30,000miles has cracked cylinder head . Mazda dealer is replacing under warranty. Dealer service rep said Mazda has “redesigned “the replacement head and acknowledged it’s a common problem with 2019 2.5 L engine.

 

[181962]

My 2019 cx5 with 2.5L engine , 30,000miles has cracked cylinder head . Mazda dealer is replacing under warranty. Dealer service rep said Mazda has “redesigned “the replacement head and acknowledged it’s a common problem with 2019 2.5 L engine.

Turbo or non-turbo?

 

[Jack Rabbit]

It will be interesting to see how the class action lawsuit concerning defective Chevy Silverado engines plays out.

Although slightly different problem... Faulty piston rings and excessive oil consumption...it should set some type of precedent as to any future Mazda engine lawsuits.