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Thread: New confusing article on the JATCO CVT7

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    Senior Member Dirk Diggler's Avatar
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    Lightbulb New confusing article on the JATCO CVT7

    https://www.transmissiondigest.com/t...lematic-cvt-7/

    The writer says this is one of his favorite transmissions to work on, but then goes on to not write one positive thing about it? Claims a new cvt cooler needs to put on every 30k miles! Lol would love to see the costs of that combined with $200 fluid changes. Is this guy for real? Wizard council, what do you think?



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    Where's the leak ma'am? Marklovski's Avatar
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    Honestly I'm pretty tired of journalists lol. If Mitsubishi didn't recommend it at 30K why would we need it? Why would Mitsubishi want your CVT to fail before 100,000 if it was really needed?
    Fuel Log: Good enough
    Instagram: @zoras_sapphire

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    Senior Member Top_Fuel's Avatar
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    ...the CVT fluid oxidizes rather quickly...smells burnt and overheated
    ...not one friction plate is burnt...Not even the converter clutch is damaged or burnt.
    ...seems to suggest the heat exchanger is insufficient in cooling the CVT fluid.
    I wouldn't completely dismiss what this guy is saying. Have you guys made similar observations about the Mirage's CVT fluid? Does it smell burnt and look bad after 30,000 miles? Has anyone ever had an oil analysis done of used Mirage CVT fluid? I think the answer is no...but it would probably go a long way into figuring out exactly how quickly CVT fluid in a Mirage deteriorates over a period of time.

    Overheating fluid seems to be an issue with the Nissan guys. You don't have to look hard to find owners installing aftermarket transmission coolers in Nissan CVTs. This video below is an example. This cooler combines a standard CVT heat exchanger with the ability to route the transmission fluid through an external traditional automatic transmission oil cooler. It's an interesting concept if you know your problem is overheating CVT fluid.

    Last edited by Top_Fuel; 07-23-2020 at 05:31 PM.

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        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 52.0 mpg (US) ... 22.1 km/L ... 4.5 L/100 km ... 62.4 mpg (Imp)


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    Senior Member Dirk Diggler's Avatar
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    With such a small engine on the Mirage, would this attribute to kess cvt overheating issues since its less taxed?

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    Senior Member Top_Fuel's Avatar
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    It would be interesting to monitor the fluid temperatures of a Mirage CVT to see if they tend to run hot.

    There is a temperature sensor inside the transmission...but you need a secondary device to read the temp from the computer...like a a ScanGauge, or a smart phone with the Torque Pro app (assuming this data is accessible in a Mirage).

    The Mirage service manual makes a few references to the "normal" operating CVT fluid temperature. For example, when checking the fluid level in a CVT, they state the fluid temp should be within the normal operating range of 50-80 C (122-176 F)...

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    So that got me to thinking...

    Exactly how hot does the CVT fluid in a Mirage have to get before the driver gets an overheating warning?

    Answer: 137 C (279 F)...

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    That's 100+ degrees above the top of the "normal" operating range. Is that too hot for CVT fluid? I don't know...but I think I might want to know what's going on in the transmission before the fluid reaches 279 F!



    Here are some interesting comments from a Fit owner who monitored the temps of his CVT over time...

    2018 Honda Fit EX w/CVT

    I have a Scangauge 2 and the ability to monitor CVT temps. 7+ months have taught me.... The car does have a CVT warmer. Basically a heat exchanger between the engine and CVT. This will bring up CVT temps quicker for fuel economy and my best guess is that once it tries to go over the engine coolant temp, then you could consider it a CVT cooler. That is very loosely said, but the truth is that it works both ways.

    So, about the temps...

    Southern Indiana Winter, under 20 degrees: The trans almost never gets over 100F degrees with my driving and short trips under 15 minutes. From there the temps creep up very slowly and I believe interstate cruising was around 150 degrees. No interstate hills in Southern Indiana.

    Spring temps into the low 70's: CVT acts just like the winter, but add about 20 degrees. It warms up sooner of course, but not a lot sooner.

    Summer 85-100 degrees: The CVT warms up incredibly quickly. I know it helps that it's already warmer to start with... With the car running between 185-190, the CVT is usually 195-205. This is interstate at 75mph. Temperature wise, I feel like interstate driving is where it sees the hottest temps and most of my driving is interstate.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 52.0 mpg (US) ... 22.1 km/L ... 4.5 L/100 km ... 62.4 mpg (Imp)


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    Senior Member Dirk Diggler's Avatar
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    I wonder if the writer was thinking a Nissan with alot more power needs a new cvt oil cooler every 30k miles and not a Mitsu?

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    Senior Member Top_Fuel's Avatar
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    Quote Originally Posted by Dirk Diggler View Post
    ...a Nissan with alot more power needs a new cvt oil cooler every 30k miles and not a Mitsu?
    Put the power issue aside for a minute. The question is does a Mirage's CVT fluid show signs of overheating when the the trans is serviced at regular intervals? I don't know the answer to that because I don't pay close attention to most CVT threads. Hopefully Fummins can weigh in on it when he gets back. I know he has posted pics similar to the ones in that article (nasty looking fluid, fuzzy magnets in the pan)...but I don't know if they were 30,000 mile fluid changes or 100k mile changes.


    ...with the same transmissions that have deteriorated fluid...each of the magnets in the pan is coated with metal particulates
    ...this metal may have entered the heat exchanger restricting the flow of the CVT fluid to be cooled.
    So this guy's theory is that the fluid may be overheating because the transmission heat exchanger is less effective because it might be plugging up with metal particles.

    Replacing the heat exchanger might not be a bad idea. On the other hand, why doesn't he just cut an old one open or flush some solvent through it and see what comes out?!?

    Again...all of this is one guy's theory and it makes for good interweb banter. None of this would matter if you could monitor the trans fluid temperature of the CVT yourself and know if it is running hot. The temperature sensor is already there. Does anyone on the forum have a ScanGauge or Torq Pro app on their CVT Mirage?!? I'm surprised someone hasn't done this already.


        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 52.0 mpg (US) ... 22.1 km/L ... 4.5 L/100 km ... 62.4 mpg (Imp)


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