2016 CX-9 Signature leaking coolant

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Mazda 2 touring
Hey guys,

This weekend the CX-9 started leaking and burning coolant. I took a look at the engine bay and I couldn’t find a leak around the any of the hoses. However, it seems to be leaking from the firewall side. I’ve made an appointment with the dealer, for this coming Saturday. I’ve been reading through the forum and this seems to be a problem, that is affecting the 2016 model years.

I’ll update as I learn more.

2016 signature
39,000 miles
 
Solution
Hey guys,

So I dropped off the CX9 today and this is a known issue (2016 model years). The service assistant confirmed this, even before I took in the car. Once the car was inspected, they determined a new engine would be required. However, they are in back order and I’ll get more information on Monday. I’ll try to get photos of the engine and more details if possible.

I think my build date is March or April 2016.
I just got out of the dealership for my 16 sport. I bought it CPO and the extended warranty for it is gonna cover the replacement of the engine. They even showed me the area the leak was in but they couldn’t figure out where it was coming from. For now I’m in a tiny cx30
 
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We finally received a rental vehicle from Enterprise paid for my Mazda. It’s a 2019 Toyota Tacoma TRD Sport and it’s super rough and clunky. I called Mazda USA’s corporate number last week to get a rental because the dealer wouldn’t give us answers and the next day we had a rental. Saturday (5/22) will be 7 weeks without the car. Last we heard the dealer is ready to install the new engine once it arrives, and they have been ready for several weeks. They keep telling us since my CX-9 is not under the factory warranty that we keep getting pushed to the bottom of the list for the new engine which is why it’s taken 7 weeks so far. Everything I have read on any forums about this issue, it’s resolved in less than a month.
 
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We finally received a rental vehicle from Enterprise paid for my Mazda. It’s a 2019 Toyota Tacoma TRD Sport and it’s super rough and clunky. I called Mazda USA’s corporate number last week to get a rental because the dealer wouldn’t give us answers and the next day we had a rental. Saturday (5/22) will be 7 weeks without the car. Last we heard the dealer is ready to install the new engine once it arrives, and they have been ready for several weeks. They keep telling us since my CX-9 is not under the factory warranty that we keep getting pushed to the bottom of the list for the new engine which is why it’s taken 7 weeks so far. Everything I have read on any forums about this issue, it’s resolved in less than a month.
I really hope you get your CX-9 back soon. That's always a pain. The delays could also be caused by the pandemic and other factors at play such as parts locations/supplies around the world, also with the logistics of shipping a whole engine it can be tricky. Remember that Mazda is a small OEM when compared to their competitors. The Taco's are truck based, unlike the Honda Ridgeline, and do tend to ride rough, I briefly had one as a work truck.

You should definitely ask your service manager some questions about your CX-9, try to dig for info on if this failure is a reoccurring problem they're noticing, and if there was any bulletins, TSB's or updates to the 2.5T Skyactiv-G engines that are related to these failures. It would be a great help for the rest of us with this engine and for future owners. OEM's don't like to share info easily, but if you come across as a concerned owner that just wants to make sure your vehicle is safe in the long term they are more likely to give you more detail. Good luck!
 
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Mine hasn’t been as long. It’ll be 2 weeks tomorrow but they did tell me that the engines are on back order and are waiting for them to ship from Japan. But I’m now seeing that a lot of people are having a hard time at the dealer. Guess I got lucky cuz the dealer I bought at and service at are doing an all star job with me.
 
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I'm starting to see more reports on the Facebook groups as well. I don't think it's limited to 2016 models. Hard to say how prevalent this will be but it's not looking good.
 
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I'm starting to see more reports on the Facebook groups as well. I don't think it's limited to 2016 models. Hard to say how prevalent this will be but it's not looking good.
Exactly.
Wonder how long til they make it a recall. The main reason I bought a CPO was because there hadn’t been any.

I’m seeing this issue with lower and higher mileage engines. And some dealers have been replacing and some (well at least one) are fixing the issue but not replacing the engine.
 
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Mine has been in shop since April 7th......Dealer still waiting on engine to arrive. Loaner is a 2021 Mazda cx5 Touring....nice car, but really miss the cx9.....
 
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Mine has been in shop since April 7th......Dealer still waiting on engine to arrive. Loaner is a 2021 Mazda cx5 Touring....nice car, but really miss the cx9.....
My loaner changed from a cx30 to a cx5. I’m not in love with it but it’ll do. They’re gonna realize how many miles I drive once they get their loaner back lol.

I was told it could be a month before I got my car back. I’ve read other places that cars out of the warranty range are being dropped to the bottom of the list.

With more and more of these issues happening it’ll be interesting to see where Mazda goes with it. I hope for nothing but the best for everyone.
 
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Been hearing that the cause of the crack is due to the loctite securing the manifold to the engine. The loctite expands and contracts. Im wondering if we can just remove those bolts and clean out the loctite?
 
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Been hearing that the cause of the crack is due to the loctite securing the manifold to the engine. The loctite expands and contracts. Im wondering if we can just remove those bolts and clean out the loctite?
If it were that simple I suspect Mazda would have done a recall and just do that as it's way cheaper than full engine replacement. Same goes for changes to torque spec. I hope you're right, and maybe they're just slow to go through with a recall, but I suspect there's more to it than that.
 
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@TitoP So Mazda appears to be fixing this issue even if the car is out of warranty?
Mine was still covered under the CPO extended warranty so it’s covered. I only took it in because I needed an oil change. But I’ve read some people are paying out of pocket for engines, some are being fixed for leaks at gaskets and some are being replaced at no cost.
Some dealers are giving some people a hard time with loaners as well
 
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But I’ve read some people are paying out of pocket for engines
If I was one of those paying out of pocket I'd be asking for my money back. Mazda needs to fix this for everyone that has this issue -- whether or not under warranty. Otherwise the 2.5T is going to get bad press and people will not want to take the chance to buy any Mazda with that engine.
 
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Hey guys,

So I dropped off the CX9 today and this is a known issue (2016 model years). The service assistant confirmed this, even before I took in the car. Once the car was inspected, they determined a new engine would be required. However, they are in back order and I’ll get more information on Monday. I’ll try to get photos of the engine and more details if possible.

I think my build date is March or April 2016.
I have a 2016 with 110,000 miles and it did the same thing, decided to do a tear down. I found the issue at least on mine is not a head gasket issue, it's the lower left side stud on the variable valve between the turbo and the engine block. Found no crack on it, there is a cooling pass built in this area, ordered new stud, should be back on the road next weekend.
 

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I have a 2016 with 110,000 miles and it did the same thing, decided to do a tear down. I found the issue at least on mine is not a head gasket issue, it's the lower left side stud on the variable valve between the turbo and the engine block. Found no crack on it, there is a cooling pass built in this area, ordered new stud, should be back on the road next weekend.
I'm not very familiar with this part of the engine. What's involved to access this?
 
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I'm not very familiar with this part of the engine. What's involved to access this?
Between the turbo and the exhaust ports there is a flapper valve you have to remove the exhaust and the turbo to get to the leaking stud and re seal it there is a cooling passage behind it.
 
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Between the turbo and the exhaust ports there is a flapper valve you have to remove the exhaust and the turbo to get to the leaking stud and re seal it there is a cooling passage behind it.
So you're thinking that the stud itself is somehow causing the leak? I'm no mechanic by any stretch, but I don't understand how that could be. That stud goes directly into a portion of the engine where it's exposed to coolant? And something happened to that stud that now allows coolant to leak? I hope you're right.

Someone else did theorize that the bolts have something to do with it, which makes some sense. Perhaps there's a crack deep inside and the crack runs along the threads of where that stud fits into?
 
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So you're thinking that the stud itself is somehow causing the leak? I'm no mechanic by any stretch, but I don't understand how that could be. That stud goes directly into a portion of the engine where it's exposed to coolant? And something happened to that stud that now allows coolant to leak? I hope you're right.

Someone else did theorize that the bolts have something to do with it, which makes some sense. Perhaps there's a crack deep inside and the crack runs along the threads of where that stud fits into?
I thought he meant the stud was cracked?
 
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