CX-9 2.5T Engine Replacement

Anyone here have issues with the 2.5T? My CX-9 is currently at the dealer getting a new engine. An issue with a vibration at idle that was caused by loss of compression in one cylinder. Pretty shocked....thankfully, covered under warranty.
 
My dealer said I’m the first case they had, but Mazda has seen a few of these cases around. My symptoms triggered tech line to recommend a compression test.
 
Bought a 2016 with 107,000 miles, it happened at 101k miles. Didn’t know until I found it in the paperwork. Didn’t show on car fax. Description in paperwork was “ Ran rough, found low compression on one cylinder”. The engine was warrantied with labor covered by owner (~$4k). Doctor previous owner then decided to get a new one a bit later.
 
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2005 Mazda3
45K miles

What year is your 2nd gen CX-9? I kind of wonder if they made any minor un-publicized fixes when they "retuned" the engine for the 2020 model and gave it a little more torque, hoping they did, but maybe they didn't.

Another user (with a 2nd gen cx-9 2.5T) also had an engine replaced, mchu123:

Here's another user (with a 2nd gen cx-9 2.5T) SaltyGoat who also had a cracked engine :

As the 2nd gen ages with the new 2.5T, it seems like quite a few cracked engine block cases are popping up. Mazda needs to look into this, especially since they plan to use this engine in virtually their whole lineup. That's a lot of potential engines they may need to replace in the future.
 
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2010 CX-9 GT
I'm sure Mazda already knows exactly how many engines they've replaced under warranty. The fact that Mazda's tech line recommended a compression test when presented with the symptoms is not a good sign. Still, there's about 5-10 posts on here, which isn't a huge number (yet?).

It appears that the part number for the short block changed, but I have no idea what is different between the two versions.
 
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2020 CX5 Signature
I'm sure Mazda already knows exactly how many engines they've replaced under warranty. The fact that Mazda's tech line recommended a compression test when presented with the symptoms is not a good sign. Still, there's about 5-10 posts on here, which isn't a huge number (yet?).

It's too bad Mazda Canada didn't share in this wisdom. They go down a rabbit hole with a parts canon before they come to the final conclusion that it has a dead cylinder. The tried sensors, spark plugs, engine decarb and injectors before they made the call to replace the engine.
 
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2005 Mazda3
I'm sure Mazda already knows exactly how many engines they've replaced under warranty. The fact that Mazda's tech line recommended a compression test when presented with the symptoms is not a good sign. Still, there's about 5-10 posts on here, which isn't a huge number (yet?).

It appears that the part number for the short block changed, but I have no idea what is different between the two versions.

They probably are aware of it by now, but they can't admit it otherwise users would outcry for a recall which would be too expensive, so they're doing the usual replace as it arises routine, which is fine. What is concerning is, even though it's just 5-10 posts on here, how many owners out there that aren't on the forum are having the same problem, I'm thinking it's widespread enough for Mazda to be on their toes. I vaguely recall that some of the owners who posted here that had the cracked block mentioned that they pushed the engine hard/drove spiritedly(but it still shouldn't be a problem), so perhaps it may be more isolated to driving habits, who knows... the engine is only 3.5 - 4 years old, and not many posters here have reached the 100k mile mark yet.

Do you have a reference to the new part number for the block?
 
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2010 CX-9 GT
They probably are aware of it by now, but they can't admit it otherwise users would outcry for a recall which would be too expensive, so they're doing the usual replace as it arises routine, which is fine. What is concerning is, even though it's just 5-10 posts on here, how many owners out there that aren't on the forum are having the same problem, I'm thinking it's widespread enough for Mazda to be on their toes. I vaguely recall that some of the owners who posted here that had the cracked block mentioned that they pushed the engine hard/drove spiritedly(but it still shouldn't be a problem), so perhaps it may be more isolated to driving habits, who knows... the engine is only 3.5 - 4 years old, and not many posters here have reached the 100k mile mark yet.

Do you have a reference to the new part number for the block?

I just went on an online parts catalog and looked up the short block for a CX-9. There's a current part number, and it lists a "superceded" number. Again, I have no idea what changed.

Current part number for the block is PY8W-10-300A.

Old part number is PY8W-10-300.
 
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2005 Mazda3
I just went on an online parts catalog and looked up the short block for a CX-9. There's a current part number, and it lists a "superceded" number. Again, I have no idea what changed.

Current part number for the block is PY8W-10-300A.

Old part number is PY8W-10-300.

Thanks for posting this. I can see now what you're saying now.


The "a" part number replaces the non-"a". Hopefully it addressed the issues we're starting to see in the original 2.5t.
 
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sm1ke

Work In Progress..
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Canada
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'18 CX-9 Signature
It seems (at least from this thread) that owners reporting these issues all have 2016 MYs. Is that correct? I'd be interested to learn when the P/N was superseded.
 
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