NA CX-5 with Cylinder Deactivation Engine Repairs - Report In

[walt]

I'm the person who posted a couple of months ago with the 2022 CX-5 NA that had the cracked cylinder head at 13,000 miles, and posted the repair invoice. In reading all the posts since that time with the discussion of the parts numbers, if I've read those posts correctly, the consensus is that the replacement kits have the same old (possibly) defective cylinder head in them. So even though my car was repaired, it may still be a ticking time bomb?

I assume that it's still a minority of vehicles that actually have had their cylinder head crack, but if there has been no improvement to the cylinder head, why is it just a minority of us having the problem? That's really just a rhetorical question, as I'm sure no one has the answer, but any theories would be appreciated (in layman's terms, I'm not a car person).

(FYI, I actually ordered the car in April, not March as I originally said. And, as someone guessed, a lot of my mileage is highway mileage.)

Exactly my concern. Same casting process and or molds it seems.
With the publicity it's just hard to imagine the lack of communication
company wide given the potential ramifications. This is assuming the crack referenced is in the same location on the head.
Not familiar with the casting process but maybe there are a number of molds and only one of them is out of spec.

 

[Kedis82ZE8]

https://static.nhtsa.gov/odi/tsbs/2023/MC-10241612-0001.pdf

Published 8.16.2023

Update from last one

"Reference Warranty Policy 3.28 MASH Authorization for Warranty Repairs to confirm whether MASH is required or not."

 

[walt]

MASH?

 

[yrwei52]

MASH?

Mazda Assistance Service Hotline.

 

[flrmazda]

Exactly my concern. Same casting process and or molds it seems.
With the publicity it's just hard to imagine the lack of communication
company wide given the potential ramifications. This is assuming the crack referenced is in the same location on the head.
Not familiar with the casting process but maybe there are a number of molds and only one of them is out of spec.

In the mid to late 2000s, I consulted for the one of the big US-German tier 1 auto suppliers with regard to casting technology, trying to develop something very low cost for emerging markets. The standard process was gravity die casting. This was also used for cylinder heads in Europe but I believe that low pressure die casting is standard in Japan. I have not been involved for 15 years.

Now, I can tell you with 99.999% certainty that bad molds is not the issue, especially with a Japanese company. I doubt even Chrysler in the 70s or 80s (or whenever the company was at its nadir) would be that incompetent. A mold could have up to a 100k unit lifetime so you would have a hell of a lot more bad cylinder heads out there. The issue is process control and the fact that (according to the Russian guy repairing the head on his US sourced Mazda 3) there is a 2 mm thick section, so you are operating at the very limit of low pressure die casting, so that's the crux of the problem. Some people say that 3 mm is the limit. I should add that gravity die casting would not be able to produce a 2 mm thick section. To safely achieve 2 mm you should do high pressure die casting, which is not suitable for this for a number of reasons.

 

[Antny]

In the last couple weeks my 2019 NA CX-5 began making a high pitch sound coming from under the car. My local mechanic traced it to the exhaust system - a flow control valve that actuates when CD is active. Has anyone else had this happen? I found one post on Reddit with this problem where the dealership had to replace the pipe and catalytic converter. I have 64,xxx miles on the vehicle.

 

[edmaz]

In the last couple weeks my 2019 NA CX-5 began making a high pitch sound coming from under the car. My local mechanic traced it to the exhaust system - a flow control valve that actuates when CD is active. Has anyone else had this happen? I found one post on Reddit with this problem where the dealership had to replace the pipe and catalytic converter. I have 64,xxx miles on the vehicle.

Your question is posted to the wrong thread - completely different subjects. There's some information in <this> thread that should help you out. But if you feel the need to discuss your issue further, then either start a new thread or post on the one that I linked above.

 

[Antny]

Sorry, I mistook this thread to be related to all problems being encountered with the 2.5l with CD.

 

[dunhillmc]

In the last couple weeks my 2019 NA CX-5 began making a high pitch sound coming from under the car. My local mechanic traced it to the exhaust system - a flow control valve that actuates when CD is active. Has anyone else had this happen? I found one post on Reddit with this problem where the dealership had to replace the pipe and catalytic converter. I have 64,xxx miles on the vehicle.

that might be covered under the 96m/80k emissions warranty