Poll 2.5T Coolant Leak/Engine Replacement. What can be done to prevent?

Who is having coolant leak issues and have had their engines replaced?

  • Yes

    Votes: 10 27.8%
  • No

    Votes: 26 72.2%

  • Total voters
    36

sm1ke

Work In Progress..
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Canada
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'18 CX-9 Signature
I posted something on another forum.. They said its a coolant leak. Likely head gasket. Its definitely not normal for the coolant to go down to the Low mark in just 60,000 kms. I’m worried this could be problematic down the road as I didn’t purchase extended warranty and plan on keeping this vehicle for 5 more years. Never thought I might be one of the “few” with coolant loss. This is a downer. I’ll fill it up to under the High mark on a cold engine and observe.


Reposting what @PTguy wrote earlier:
The coolant level in the plastic expansion tank directly relates to the coolant temperature. The coolant temperature relates to both the load on the engine and the heat of the day. You want it above L when everything is cold, and you want it up to F after working hard on a hot day. The actual level isn't as important as having a consistent level at a consistent temperature.

I'd just fill it to the middle one a cold engine (or maybe an inch or two below the fill line) to account for expansion. But as @PTguy mentioned, "the actual level isn't as important as having a consistent level at a consistent temp".
 
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2020 CX-5 AWD
I didn't see it posted previously, so I'll mention that when monitoring for coolant loss, the coolant level at the radiator cap also needs to be checked, along with the level in the overflow tank. Check both only on a completely cold engine, and do a visual on the overflow level first, before removing the cap to check the level there.
 
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2019 Mazda CX-9 Signature
So i called mazda this morning and the service advisor said its completely normal for the coolant to be at the low mark even if the engine is hot. He said its just an expansion tank and to not add anymore coolant to it. If it was leaking i would clearly see a leak somewhere according to his words so looks like i will just observe this regularly
 
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Pueblo county CO
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CX-5 Sport 16.5 6M
I posted something on another forum.. They said its a coolant leak. Likely head gasket. Its definitely not normal for the coolant to go down to the Low mark in just 60,000 kms. I’m worried this could be problematic down the road as I didn’t purchase extended warranty and plan on keeping this vehicle for 5 more years. Never thought I might be one of the “few” with coolant loss. This is a downer. I’ll fill it up to under the High mark on a cold engine and observe.
Any coolant leaking into the oil is bad, head gasket is probably the worst. Also pretty rare.

Are you sure your Mazda started with the coolant at the F mark?
 
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2019 Mazda CX-9 Signature
Any coolant leaking into the oil is bad, head gasket is probably the worst. Also pretty rare.

Are you sure your Mazda started with the coolant at the F mark?
Quite certain it was at or near full. The engine may have been hot at the time though.
 
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Winnipeg Canada
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2017 CX-9 GT
I don't think that was me. Normally I check the coolant level at every oil change, and its always been at a normal level. It seems to only have dropped recently. Even now, the car doesn't drip anything, and I don't think there is any indication of coolant pooling on the plastic panel that covers the oil filter. No odd smells coming from the engine bay either.

Maybe the leak isn't on the engine itself, but that wouldn't explain the high potassium reading from my last UOA.
It could also leak in the turbo and be blown into the combustion chamber and past the piston rings.

EDIT: Not sure if that's even possible, but i do believe there are coolant lines that go to the Turbo.
 
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2019 Mazda CX-9 Signature
Trix, do you always park in the same place? Look for drops of coolant under the engine there.

A $30 oil analysis will show if the oil contains any antifreeze.
https://www.blackstone-labs.com/tests/standard-analysis/
Yeah its parked in the same place, but the outside driveway has a crazy incline since the garage is below ground so nothing really pools up. I may consider the oil analysis but I’ll wait a bit longer
 
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2010 CX-9 GT
It could also leak in the turbo and be blown into the combustion chamber and past the piston rings.

EDIT: Not sure if that's even possible, but i do believe there are coolant lines that go to the Turbo.

Water leaking into the turbo and into the intake or exhaust is not likely. Oil, yes. Water, no. The bearings can sometimes leak oil into the intake or exhaust if the oil pressure is off or the bearings get trashed, but the water circulates through the bearing housing and doesn't have a path into the guts of the turbo unless something cracks. The bearing housing usually doesn't have cracking problems because its temperature is more tightly regulated.
 
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2017 CX9 GT AWD
I updated the thread to include a poll now of who is and isn't having this issue.

If you've had this done, please comment on the model year, how many miles you had when it occurred, when you first noticed the issue, if Mazda covered the cost under warranty, and any other details.

Also those with higher miles and no issues let us know how many miles so far.
 
2016 sport. ~82k. Must’ve started leaking between oil changes since that’s when it was noticed at the dealer. I did see a spot but never looked right before starting the car. I always warm it up and have the AC on so I thought it was condensation as I had seen that before. The dealer even showed me the location they noticed coolant coming from and told me in the spot that Mazda was just replacing the engines and not trying to trouble shoot it.
Mazda is currently in process of replacing my engine. Gonna be almost 4.5 weeks from the time they kept it to the time I get it back.
 
'17 signature, 58k, coolant leak, engine replacement under warranty. brought it in for oil change and the dealer found the issue, and started the repair work.
 
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2017 CX9 GT AWD
When I first checked while the engine was warm, the reservoir was about halfway in the middle between full and low. A few hours later it was about 1/3 above the low. I'm having the oil changed next week and will see what the coolant level is going forward.
Had mechanic check the compression and do a visual check of engine for any coolant leaks. All looks good.

But I'm going to be watching this closely and really won't feel comfortable until Mazda addresses this issue publicly and say they'll replace the engine with this problem even out of warranty.
 
2016, 80k Miles
I am outside of the factory warranty from Mazda, I do however have an extended warranty. The extended warranty ruled NOT to cover the engine replacement. Mazda USA has decided to cover all costs with the engine replacement even outside of the warranty. This includes parts, labor, and an enterprise rental.
I still do not have my car back from the dealer and it has been roughly 9 weeks, my engines ship date according to the dealer is 6/9/21.
 
I also hope that Mazda addresses it publicly. I’m not sure if a recall is needed but maybe a Special Service Program of sorts is the right solution?
Had mechanic check the compression and do a visual check of engine for any coolant leaks. All looks good.

But I'm going to be watching this closely and really won't feel comfortable until Mazda addresses this issue publicly and say they'll replace the engine with this problem even out of warranty.
 
2016, 80k Miles
I am outside of the factory warranty from Mazda, I do however have an extended warranty. The extended warranty ruled NOT to cover the engine replacement. Mazda USA has decided to cover all costs with the engine replacement even outside of the warranty. This includes parts, labor, and an enterprise rental.
I still do not have my car back from the dealer and it has been roughly 9 weeks, my engines ship date according to the dealer is 6/9/21.
Seems to me that if Mazda is covering the costs, they’re trying to keep it on the low. Without coming out and acknowledging the issues with a recall, they’re hoping to save money
 
I got an update today. Engine came in and work was started but they needed to order some bolts. Looking at hopefully about another week at the dealer.
 
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2019 CX-9 Signature
I really hope Mazda would step up and explain the situation of this engine issue. If this is isolated problem or somewhat wild spread. What's the cause of the issue and if anything could be done to prevent or fix this. I think this is making a good amount of owners thinking twice about whether to keep this car or any of their 2.5T cars past the powertrain warranty.

I'm not positive that if Mazda will be keep covering the cost to fix this problem. I'm now considering to purchase the extended powertrain warranty to 100k. But hearing from here that not every extended warranties are created equal. One decided not to pick up the tap for the engine replacement. Where is a good place to get the extended warranty? The dealership or online?
 

sm1ke

Work In Progress..
Moderator
Contributor
:
Canada
:
'18 CX-9 Signature
I really hope Mazda would step up and explain the situation of this engine issue. If this is isolated problem or somewhat wild spread. What's the cause of the issue and if anything could be done to prevent or fix this. I think this is making a good amount of owners thinking twice about whether to keep this car or any of their 2.5T cars past the powertrain warranty.

I'm not positive that if Mazda will be keep covering the cost to fix this problem. I'm now considering to purchase the extended powertrain warranty to 100k. But hearing from here that not every extended warranties are created equal. One decided not to pick up the tap for the engine replacement. Where is a good place to get the extended warranty? The dealership or online?

The main thing to keep in mind with extended warranties is reading the fine print so that you know exactly what will be covered, and how to keep the extended warranty intact. As far as I know, the equivalent of an extended warranty from Mazda is the Mazda Protection Product (MPP) Vehicle Service Agreement (VSA). Here's a link to the MPP VSA for the Powertrain. After reading the PDF, I'd contact Mazda via email asking to clarify what exactly is covered, for how long, and if there are any criteria that must be followed in order to keep the VSA intact.

Generally, you'll want to avoid third-party insurers for extended warranties. They usually have more criteria to follow (all maintenance and service must be done at dealer A, Mazda OEM parts purchased from dealer only, etc.). On top of that, some of these insurers may go bankrupt, at which point you'd be SOL if you ever needed to use the insurance.

As far as buying the MPP VSA, it would probably be best to get quotes from as many dealers as you can - location shouldn't matter if you can pay over the phone. The price for products like these is always negotiable, so try to find the best deal, or negotiate to a price you're comfortable paying (if you decide to buy the MPP VSA).