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

aside from the engine compartment smoke, Did you have any burnt oil on outside of engine/underneath or oil puddles?

Or smoke coming out tailpipe?

I still do not have any oil puddles under the car in the garage. I can now see some oil on the undercarriage plastic towards the back of the compartment (below the exhaust heat shield). I think most of the oil is getting evaporated/burnt off in the engine compartment while the car is running because the smell is damn awful when driving. I don't notice anything too different with the exhaust out the tailpipe.

The Mazda dealer that I bought/service the car from sells about 50-60 CX5's a month (pre-COVID while they still had cars to sell) and I am the first CX5 (first 2.5L N/A SKYACTIV G for that matter) with an oil leak at the dealership. Based on this rudimentary analysis, I would say it's not a widespread issue across the 2.5L N/A motors w/ CD.
 
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what is it in this case?

I think the service advisor should have stated cracked cylinder head at cylinder 2 (not a crack in cylinder 2). In any case, they will be replacing the cylinder head when the part arrives (hopefully shortly after the new year). Only downside to living in Canada is that the same TSB (that is issed by Mazda North America Ops) does not apply here.
 
IThe Mazda dealer that I bought/service the car from sells about 50-60 CX5's a month (pre-COVID while they still had cars to sell) and I am the first CX5 (first 2.5L N/A SKYACTIV G for that matter) with an oil leak at the dealership.
Every car dealer is trained to tell its customers that “we’ve never seen this problem before” no matter how wide-spread the problem is. Heard this too many times.

If there’s a TSB or Service Alert, that indicates there’re plenty of cases for the problem. Hence the TSB or SA is issued.


⋯ Based on this rudimentary analysis, I would say it's not a widespread issue across the 2.5L N/A with cylinder deactivation motors.
Fixed.
 
Every car dealer is trained to tell its customers that “we’ve never seen this problem before” no matter how wide-spread the problem is. Heard this too many times.

If there’s a TSB or Service Alert, that indicates there’re plenty of cases for the problem. Hence the TSB or SA is issued.



Fixed.

I guess I've been lucky with vehicles (not that I have owned very many of them; maybe I'm not old enough to have experienced anything). This is the first motor related issue in my 22 years of driving (and I come from a family that buys new and drives it down to the ground. All vehicles have hit a minimum of 10 years on the road).

It's too bad that the TSB/SA from Mazda NA Ops is meaningless here in Canada; we just don't have the #'s like the US.
 
Every car dealer is trained to tell its customers that “we’ve never seen this problem before” no matter how wide-spread the problem is. Heard this too many times.


Fixed.
I won't generalize it that much.
Some dealers are fair to deal with.

There was a wheel issue with older Mazda6. The clear coat peeled off and it happened to mine. When I pointed it out to the service advisor of a dealer I frequent, he said, "This is common. I will take care of them for you!" He replaced all four wheels when only 1 or 2 showed the problem. "Same batch." He said.

So, your mileage might vary when dealing with service advisors.. Some go extra miles for you, others are out to lighten your wallets.
 
I made an account just to reply to this thread. I've been a tech for Mazda for over 15 years now, doing my second bad head related replacement today actually. The first time I found one was on a CX9. No complaints, was just a simple 16k service and I noticed that the oil and coolant had mixed together, opened a ticket to Mazda Canada and they sent an engine replacement. Now the problem is so common that we just replace the head and gasket. The problem seems to be from a small crack in the head near the exhaust manifold bolts. The engine will either leak coolant or oil depending on where it's located, but the leak gets worse the hotter the engine gets. Thanks to supply problems, took well over 2 months to get the parts needed to repair this CX5 I'm working on today. As far as how common this is, my dealership has done maybe 9 or 10 heads in the last year.
 
I made an account just to reply to this thread. I've been a tech for Mazda for over 15 years now, doing my second bad head related replacement today actually. The first time I found one was on a CX9. No complaints, was just a simple 16k service and I noticed that the oil and coolant had mixed together, opened a ticket to Mazda Canada and they sent an engine replacement. Now the problem is so common that we just replace the head and gasket. The problem seems to be from a small crack in the head near the exhaust manifold bolts. The engine will either leak coolant or oil depending on where it's located, but the leak gets worse the hotter the engine gets. Thanks to supply problems, took well over 2 months to get the parts needed to repair this CX5 I'm working on today. As far as how common this is, my dealership has done maybe 9 or 10 heads in the last year.
2.5 Turbo, 2.5 N.A., or both?
 
I believe it is only on 2.5T due to higher pressure in cylinders.
At least for this thread, the oil leak is specifically on the 2.5L with cylinder deactivation due to cracked cylinder head.
 
I made an account just to reply to this thread. I've been a tech for Mazda for over 15 years now, doing my second bad head related replacement today actually. ....
A couple of questions for you.

There have been some posts here of owners being told that the engine needs to be removed in order to replace the head. I'd be expecting you guys to never prefer that, instead of just doing the job with the engine in the vehicle. So which way does it get done at your shop?

Second question is that bit I read in the Mazda TSB about tying the timing chain up with string during the head removal and install. I'm assuming they said to do it that way in order to avoid having to remove the chain cover and everything else related to doing it that way. So do you actually tie the chain up the way the TSB says, or do you remove the timing cover in order to have full access to the chain?
 
A couple of questions for you.

There have been some posts here of owners being told that the engine needs to be removed in order to replace the head. I'd be expecting you guys to never prefer that, instead of just doing the job with the engine in the vehicle. So which way does it get done at your shop?

Second question is that bit I read in the Mazda TSB about tying the timing chain up with string during the head removal and install. I'm assuming they said to do it that way in order to avoid having to remove the chain cover and everything else related to doing it that way. So do you actually tie the chain up the way the TSB says, or do you remove the timing cover in order to have full access to the chain?
We never remove the engine, requires the subframe to come down and a LOT more work afterwards including an alignment. I'm also not sure how you could do this job without removing the timing chain altogether, because both cams come out during the head replacement and the actual timing chain cover is bolted in some places to the head. The job is a messy pain in the rear, and warranty pays next to nothing compared to CP. But right now during slow season we welcome this sort of work. Just a shame it's happening, but luckily every single repair we have done has been covered by Mazda with the customer in a rental. Sometimes for weeks or months.
 

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... I'm also not sure how you could do this job without removing the timing chain altogether, because both cams come out during the head replacement and the actual timing chain cover is bolted in some places to the head.
I got my wires crossed on that, thinking about the switchable HLA replacement procedure instead of this one. I've been looking at lots of TSBs related to these vehicles, and sometimes they all just start to run together. Sorry about that:rolleyes:

.... and warranty pays next to nothing compared to CP. ...
Based on what I've seen posted by techs on other forums in the past, that seems to the rule for most automakers across the board. And some guys have said it was one of the primary reasons they moved on to indy shops.

... but luckily every single repair we have done has been covered by Mazda ...
Maybe your ship will come in when warranties are over, and all of them will be CP. By that time, you'll be so fast doing the job that you'll be able to crank out 2-3 a day ;)
 
We never remove the engine, requires the subframe to come down and a LOT more work afterwards including an alignment. I'm also not sure how you could do this job without removing the timing chain altogether, because both cams come out during the head replacement and the actual timing chain cover is bolted in some places to the head. The job is a messy pain in the rear, and warranty pays next to nothing compared to CP. But right now during slow season we welcome this sort of work. Just a shame it's happening, but luckily every single repair we have done has been covered by Mazda with the customer in a rental. Sometimes for weeks or months.
So you have been replacing the cracked cylinder head for the 2.5L with cylinder deactivation and the 2.5T? There’s a TSB for coolant leak on the 2.5T due to cracked cylinder head too.
 
So you have been replacing the cracked cylinder head for the 2.5L with cylinder deactivation and the 2.5T? There’s a TSB for coolant leak on the 2.5T due to cracked cylinder head too.
Yeah. Seems it's all 2.5L within those few years. I'm still not even clear how it happened. I can only imagine a screw up at the plant somewhere. I've never seen a Mazda 3 or 6 with this problem at my shop, just CX5 and CX9 right now.
 
.... I'm still not even clear how it happened. I can only imagine a screw up at the plant somewhere.....
Some guy (not a regular) on another forum posted that these failures are caused by one of those manifold bolts being over-torqued by a bot at the factory. He just stated it as a fact, but didn't offer any reference to a source, or other type of proof, No idea about the validity of this, and I'm certainly not passing it along with any degree of credibility. But I did think it was interesting the way he just wrote it as if it were common knowledge.
 
Yeah. Seems it's all 2.5L within those few years. I'm still not even clear how it happened. I can only imagine a screw up at the plant somewhere. I've never seen a Mazda 3 or 6 with this problem at my shop, just CX5 and CX9 right now.
When you say it’s the CX-5, it has both 2.5L with CD and 2.5T, but when it’s the CX-9, it’s only the 2.5T. The cylinder head assembly is deferent between these two engines. Based on the very recent TSB 01-013/21 for coolant leak on the 2.5T, the leak happens at the cylinder head around the exhaust manifold. There may be cracks at the stud bolt hole or at the outside of the exhaust manifold. In addition, Mazda has since modified the cylinder head and exhaust manifold gasket trying to fix the problem.

Cracks may be caused by:
• Deformation of the exhaust manifold during usage causing unexpected force to certain areas of the cylinder head.
• Residual stress generated during production in the cylinder head material may be greater than expected. The external force from the exhaust system when driving over bumps may cause unexpected force to certain areas of the cylinder head.


2.5T Engine Coolant Leaking TSB
 
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I got my wires crossed on that, thinking about the switchable HLA replacement procedure instead of this one. I've been looking at lots of TSBs related to these vehicles, and sometimes they all just start to run together. Sorry about that:rolleyes:


Based on what I've seen posted by techs on other forums in the past, that seems to the rule for most automakers across the board. And some guys have said it was one of the primary reasons they moved on to indy shops.


Maybe your ship will come in when warranties are over, and all of them will be CP. By that time, you'll be so fast doing the job that you'll be able to crank out 2-3 a day ;)
What is CP ?
 
Finding this thread has been a relief. I have 2019 Mazda 3 with CD that’s been at the dealership for two months. I’m finally getting it back this Saturday after discovering oil at the bottom of the engine bay. This entire ordeal was a headache and I was barely updated on the status of my vehicle. I really hope the replacement was done well but the service center has left a sour taste in my mouth. From the service adviser telling me that oil was not replaced but “topped up”, to the manager telling me that’s incorrect, it was in fact drained and replaced with new oil. I have no faith in Mazda service centres. They wouldn’t even replace a $10 filter after having my car for two months, knowing it was due for an oil change within a few KM’s! I was a Mazda fan boy and recommend them to everyone I come across. After this experience I’ll be trading it in after my warranty is up. Who’s to say the cylinder head won’t crack again and that’s not an issue I want to deal with out of warranty.

Mazda moving “upscale” is a gimmick and why the hell was CD even introduced in the first place? It barely saves gas. The fact they got rid of it for the 2021 MY goes to show you that it was an unnecessary and problematic feature to add.
 
just change the oil and filter to be on the safe side if you dont trust them.
When mine was at the shop for different issue oil pan was down but oil and filter were never changed. After few hundred miles it then broke the oil control valve because of junk stuck in it and it had to be changed as well.

by the way CD is still there in cx5 even on new models. just on those that are not turbo.
 
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