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  1. J

    2.5T Engine Coolant Leaking TSB

    I'm speculating here, but it is probably because the engine block is too close to the side of the engine bay to get to the timing chain. You have to l get the timing chain off the camshafts to pull the head. The old V6 is wedged in so tight that the factory service manual tells you to pull...
  2. J

    2.5T Engine Coolant Leaking TSB

    Aluminum heads and engine blocks warp slightly in use. Any time you replace a head gasket, you have to check the head and block for warping. If either is out of spec, that surface needs to be machined ("decked") to guarantee that the gasket will properly seal. Decking an engine block is...
  3. J

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

    Given all the reports coming in, this warrants its own thread. Mods?
  4. J

    2016 CX-9 Signature leaking coolant

    Certainly sounds like a cracked cylinder head. If you have coolant all the way up at the exhaust manifold, it's probably coming from the head. Good luck. Mazda has been stepping up and covering these, even those that were out of warranty.
  5. J

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

    On the other hand, Mazda is moving to a native rear wheel drive platform with a longitudinal inline 6. This is definitely the right direction if you are an enthusiast. I remember Mazda used to be called the "Japanese BMW" by some car magazines. They might actually start making better BMWs...
  6. J

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

    I was not trying to impugn the rotary engine or Mazda's implementation. I am well aware of the Wankel's quirks. If Mazda every releases something more in line with the FD RX-7 and makes me forget the RX-8, I'll be first in line.
  7. J

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

    Mazda has some experience with replacing large numbers of engines. If this becomes a truly widespread issue, I would imagine they will set up a remanufacturing shop and start shipping remanufactured engines to people who experience this failure. They did this before with the rotaries in the...
  8. J

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

    Good luck. NHTSA won't do anything unless they are convinced there is a safety issue. Hopefully enough people complain that Mazda is shamed into formally starting a service campaign, rather than the case by case goodwill that appears to be happening now.
  9. J

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

    Let's put it this way: if Ford and Mazda were never forced to recall the V6 because of the propensity for a water pump leak to trash the engine, why do you think NHTSA will step up and force a recall for a cracking issue? I just don't see it happening.
  10. J

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

    What outcome are you hoping to achieve by reporting this to NHTSA? This is not going to be categorized as a safety issue. The engine doesn't fail catastrophically, leaving you in a dangerous situation.
  11. J

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

    What is likely happening is that the head is developing hairline cracks at the holes where the exhaust manifold bolts/studs go, due to cyclic thermal stresses. That part of the head gets really hot when the engine is running, it is made of aluminum which expands quite a bit with temperature...
  12. J

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

    Looks like 2020 got the slight bump in torque on premium, so the 2016-2019 all had 310. I thought it was earlier than that. My mistake.
  13. J

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

    In 2018 and newer vehicles this is true. However, this is incorrect for the 2016 and 2017 models, which made 310 regardless of octane.
  14. J

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

    The peak torque occurs at about 2k RPM and is not impacted by reduced octane. This theory doesn't bear scrutiny.
  15. J

    2011 CX-9 water pump failure

    It's a bit of a gamble to fix it which is why the dealers typically just jump straight to replacing the engine. It's impossible to know the condition of the crankshaft bearings, connecting rod bearings, and the crankshaft surfaces without really ripping into the engine, which costs big money...
  16. J

    2011 CX-9 water pump failure

    I've read a number of posts about this failure and the stories seem to fall into a couple categories: 1. The check engine light comes on, and the code is related to a timing disagreement between one or both camshaft sensors and the crank sensor. This is likely caused by the oil getting...
  17. J

    2011 CX-9 water pump failure

    The class action suit has been mostly dismissed, I think all but a couple claims have been tossed out. I wouldn't expect any relief to come of this, Ford is choosing to litigate rather than settle. It's a poor design, but the plaintiffs in the case haven't produced evidence that Ford knowingly...
  18. J

    RUMOUR: New CX-9 (possibly CX-90) destined for release in 2024

    Mazda has been working on this for several years now, you can find patent documents out there from years ago. They describe the Skyactive-X version of this engine along with a hybrid architecture. It would not be surprising if Mazda disassembled a few BMW engines while designing their own I6...
  19. J

    RUMOUR: New CX-9 (possibly CX-90) destined for release in 2024

    Mazda's website says "three new SUVs by 2023": https://www.mazdausa.com/vehicles/future-crossover-suvs
  20. J

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

    Yes, I was being somewhat sarcastic in my previous post. Mazda has sold maybe 200k of these engines in the US, and only a fraction of those have accumulated mileage above the 40k+ mile level. To see a stack of failed engines isn't a good sign. I'd expect this to keep happening, the only...