Poll 2.5T Coolant Leak/Engine Replacement

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

  • Yes

    Votes: 30 35.7%
  • No

    Votes: 54 64.3%

  • Total voters
    84
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22 CX-9 GT
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21 6 Carbon
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The way I read it is Mazda added a turbo to an engine head that wasn’t designed for the additional stress it caused.
 
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18 Mazda CX5 AW
I traded in my 2016 CX-9 with an active leak. I answered all their questions truthfully but did not offer any extra information. At first, it was a sight unseen offer (didn’t plan on buying when we visited). Showed up the following day and they did their inspection and did not find the coolant leak or did find it and didn’t care. Got average trade in estimate for it. K-seal was recommended to me by an older gentleman who said he used to work for a dealership that would throw that in any car that had a coolant leak. Not sure if it would work or the legality of that

This coolant leak issue is why I started getting oil sample analyses done every oil change. They never detected it. My nose detected it before anything else. Kind of sweet kind of warm celery smell when standing near the vehicle after turning the engine off.
Yeah. I was thinking of getting another analysis by another lab done as well to compare. Seems some labs have disappeared. Is WIX UOA any good?
 
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18 Mazda CX5 AW
No it's more both a design flaw and manufacturing problem.

Added stress from a Turbo wouldn't explain the NA cracked cylinder heads. Design was weak from the start for a high pressure engine coupled with possibly overtorqued bolts at factory.
 
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18 Mazda CX5 AW
I thought this thread is specifically for the 2.5 Turbo engine.
My bad.

The head problem/coolant leaks seem to be happening on both
CX-5 and CX-9 turbos and non turbos...didn't realize which thread this was. And for it to happen across both lines and engines means the something in the design was flawed from start, regardless of which model or engine.
 
My bad.

The head problem/coolant leaks seem to be happening on both
CX-5 and CX-9 turbos and non turbos...didn't realize which thread this was. And for it to happen across both lines and engines means the something in the design was flawed from start, regardless of which model or engine.
I've never heard of this problem on the NA engines. Where have you heard this?
 
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22 CX-9 GT
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21 6 Carbon
There were reports of the 2.5 NA with cylinder deactivation having a cracked head. The regular 2.5NA is solid though.
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There were reports of the 2.5 NA with cylinder deactivation having a cracked head. The regular 2.5NA is solid though.
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This is simple. US spec. Quality of gasoline in north America is inferior. They needed to reduce compression slightly to compensate. I wonder why the earlier skyactiv enginesn don't have this problem. Didn't these model skyactiv engines get some sort of update which changed the torque curve slightly?
 

sm1ke

Work In Progress..
Moderator
Contributor
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Canada
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'18 CX-9 Signature
There's been a lot of unrelated cross talk involving the 2.5 NA engine in 2.5 turbo engine threads, and vice versa. We need to be more careful about this as it just creates unnecessary confusion (as it has above).

If you are going to post, please doublecheck the thread title to ensure you are posting in the correct thread.
 
Follow up to the issues I had after a new cylinder head installation. The dealer took a look at our car and found a hose clamp that was not seated correctly. Not sure why it didn't leak immediately but this was our first "longer" drive after the cylinder head was replaced. Dealer replaced the hose clamp for free and all has been good for the past few weeks.
 
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North of Toronto
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2019 CX-9 Sig
At this point, I'm looking for puddles and sniffing like a hound hoping to find the issue. Better now, since with a new engine I'd be good to go. If this happens instead on a trip, a few months out of warranty...

Nope, I'm not dreading it, I'm hoping for it. 2 yr countdown for me to have this happen.
 
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2016 CX-9 GT
Yeah. I was thinking of getting another analysis by another lab done as well to compare. Seems some labs have disappeared. Is WIX UOA any good?
I’ve only used Blackstone and only on my turbo vehicles. Both times I found the coolant leak before anything showed in the oil according to them. I am 0 for 2 on turbo engines. I had heard of Blackstone the most so assumed they were the best, but I guess may be all marketing. Or there really wasn’t much coolant in the oil for either vehicle when I got rid of them
 
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2016 CX-9 GT
At this point, I'm looking for puddles and sniffing like a hound hoping to find the issue. Better now, since with a new engine I'd be good to go. If this happens instead on a trip, a few months out of warranty...

Nope, I'm not dreading it, I'm hoping for it. 2 yr countdown for me to have this happen.
Drive it hard and hit every pothole you can at speed I guess since bumps can cause it
 
Tomorrow I’ll be going for an oil change. I’ll try to get some actual information from the tech. They’ll have a good idea of how many cars come to the dealer with the problem in 1 week, 1 month….
 
How many do they sell in a week?
Mazda has 544 dealers in the US. They sell roughly 31000 CX9 per year. How many cars getting work per dealer monthly is a mystery, but I have a feeling the numbers are larger than what someone posted before percentage wise.
Techs don’t talk about it or maybe they are told not to say anything.
 
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Mazda has 544 dealers in the US. They sell roughly 31000 CX9 per month. How many cars getting work per dealer monthly is a mystery, but I have a feeling the numbers are larger than what someone posted before percentage wise.
Techs don’t talk about it or maybe they are told not to say anything.

Per year sales, not month.
 
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2010 CX-9 GT
Mazda has 544 dealers in the US. They sell roughly 31000 CX9 per year. How many cars getting work per dealer monthly is a mystery, but I have a feeling the numbers are larger than what someone posted before percentage wise.
Techs don’t talk about it or maybe they are told not to say anything.

Mazda and Ford were also pretty tight lipped about the water pump issues on the old V6, so the silence is par for the course.

It looks like Mazda sold about 120k CX-9s during the 5 year period the TSB references. Doing some back of the envelope math, the average dealer would have sold slightly less than 1 per week. If they are repairing 1 a week, that's not a good sign... You said they had 3 in for this work?