# This is Your CVT Fluid Temperature (Chart)



## AlphaBetaUser (Mar 21, 2021)

Drove the Rogue and took the freeway today, and I thought I should log the CVT temperature and find out how hot it gets in a normal traffic in freeway:

The small range that I marked, shows that the CVT temperature raised a bit faster than normal. That was where the traffic got going again and I revved it up. Clearly you can see how belt/pully friction generated heat and changed the temperature quickly from 64C to 70C in 95 seconds.








Caption: 2019 Rogue FWD 23K miles. No CVT service yet. The fluid get to 72C in about 10-15 minutes driving.

The one important takeaway: Don't push the gas pedal too hard from stop!


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## VStar650CL (Nov 12, 2020)

AlphaBetaUser said:


> The one important takeaway: Don't push the gas pedal too hard from stop!


That rise isn't all from friction, it's also residual engine heat from the initial highway run that cooked a bit when you slowed down (the water pump slows too), then hit the radiator when you picked up speed again. There's no temp sensor on the radiator bottom tank, but if you put one there you'd see a strong correlation. That's why an add-on accessory cooler in series with the OE cooler is such a good idea with CVT's. Trannies wear faster when cold just like engines do, so the optimum setup is to get to operating temp quickly and then hold it steady regardless of load. Substituting an accessory cooler deprives the CVT of engine heat for rapid warmup, but putting one in series with the OE cooler retains a fast warmup while keeping "spikes" from excess engine heat from dumping into the CVT. Best of both worlds.


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## AlphaBetaUser (Mar 21, 2021)

That is such a great idea and a practical solution, why Nissan isn’t implementing it in the new CVTs? (Or maybe it has already).

It sounds like the CVT fluid change is wasting time and resources compare to installing an auxiliary heat exchanger in series with the transmission cooler! (Anyone out of warranty should do it if costs permit it).


In lack of such auxiliary heat exchanger, turning on the AC should help cooling down the coolant and therefore, prevent dumping that residual heat to the transmission cooler, is that an accurate statement? Nit sure if AC automatically turns on the radiator fan, if so, it should lower the coolant temperature.


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## VStar650CL (Nov 12, 2020)

AlphaBetaUser said:


> It sounds like the CVT fluid change is wasting time and resources compare to installing an auxiliary heat exchanger in series with the transmission cooler! (Anyone out of warranty should do it if costs permit it).


Don't get that idea for even a minute. Heat isn't the only enemy of the fluid, shear force also gradually destroys the long chain molecules. That's worse when you're a leadfoot, live around steep hills, or trailer. Change the dang fluid!



AlphaBetaUser said:


> In lack of such auxiliary heat exchanger, turning on the AC should help cooling down the coolant and therefore, prevent dumping that residual heat to the transmission cooler, is that an accurate statement? Nit sure if AC automatically turns on the radiator fan, if so, it should lower the coolant temperature.


In cooler temperatures yes, but not if the A/C is doing any real work. Then the condenser (which is in _front_ of the radiator) is actually dumping heat _into_ the system.


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## rogoman (Dec 16, 2004)

AlphaBetaUser said:


> That is such a great idea and a practical solution, why Nissan isn’t implementing it in the new CVTs? (Or maybe it has already).
> 
> It sounds like the CVT fluid change is wasting time and resources compare to installing an auxiliary heat exchanger in series with the transmission cooler! (Anyone out of warranty should do it if costs permit it).
> 
> ...


Don't be foolish. Even if you don't install an auxiliary cooler, the CVT fluid needs to be changed periodically in order to enhance longevity. The CVT fluid should always be replaced every 30,000 mi. When the fluid stays in too long, the chemical properties of the fluid get compromised and it can no longer provide that cushion that's so needed between the steel belt and the cones. You can generally deduce that by looking at the fluid; if it's very dark brown and has a burnt odor, it's shot!


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## AlphaBetaUser (Mar 21, 2021)

Definitely I will stick to “Change CVT fluid every 30K miles”. 
I was trying to compare early fluid change to an auxiliary heat exchanger. 



I have changed my transmission fluids in the past way earlier than manufacturer’s recommendation. Will do the same on the Rogue. 


On that note:
What is the fluid capacity of a FWD CVT?
And what dealers do to change the fluid? Flush? Or drain 2-3 quarts, and replace it with new fluid?


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## VStar650CL (Nov 12, 2020)

They generally take about 4-1/2, and since there's no stick, it's perfectly acceptable to measure what you drain and then add back in exactly that much. However, exactly means _exactly_. The old A/T wisdom about "erring on the side of too much" will destroy a CVT. Even a half quart of overfilling will cause the fluid to foam, which will quickly ravage the belt. On the other hand, half a quart underfilled won't hurt a thing except to make the fluid wear out quicker. So CVT's are exactly the opposite of a conventional A/T, if you err at all then err _low_. They're really designed to be filled using a bottom-up pump with a special fitting, but there is a short-cut method for models that have an upper drain bolt in the housing. Your '18 probably has one, and there are many YouTube vids about how to employ it. Basically you put in 5 quarts, jack the vehicle level on a lift or 4 jackstands, warm it up completely, then yank the upper drain and let fluid run out until the stream "hiccups". The fluid is ideal at that point and you reinstall the plug.


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## molsoncanadian (May 2, 2021)

VStar650CL said:


> Basically you put in 5 quarts, jack the vehicle level on a lift or 4 jackstands, warm it up completely, then yank the upper drain and let fluid run out until the stream "hiccups". The fluid is ideal at that point and you reinstall the plug.


Couple of questions if you guys don't mind me hi-jacking this... 1) the upper drain that you mentioned, is this the Overflow plug (14mm, iirc)? 2) Is there an average amount of time it would usually take for the ATF temp to reach 95°F to 113°F? The manual says to pull the overflow bolt at between the mentioned temps, but my generic, end-user scan tool cannot access this information (although I do see a ECT when in the TCM scan, but I think that's just the coolant temperature, because I see the same value under ECT in the ECM scan mode).

As its been mentioned here, the exact amount of fluid is crucial for this CVT. So, by ensuring the right amount of fluid via removing the overflow bolt at the right temp, one needn't worry about too much or too little fluid or how well it was filled in the past...

I was thinking of getting a laser thermometer to shoot at the trans pan to get the temp for this procedure, but if "warmed up completely" is within the range of the 95-113 temp, this would mean less expensive tools to own...


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## VStar650CL (Nov 12, 2020)

molsoncanadian said:


> Couple of questions if you guys don't mind me hi-jacking this... 1) the upper drain that you mentioned, is this the Overflow plug (14mm, iirc)? 2) Is there an average amount of time it would usually take for the ATF temp to reach 95°F to 113°F? The manual says to pull the overflow bolt at between the mentioned temps, but my generic, end-user scan tool cannot access this information (although I do see a ECT when in the TCM scan, but I think that's just the coolant temperature, because I see the same value under ECT in the ECM scan mode).


Not at all, happy to help. Yes, the overflow bolt is up and to the left of the pan as you're looking from the front of the car. The temp sensor is inside the VB right behind the oil pan, so shooting the pan with a laser thermometer should work just fine.


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## VStar650CL (Nov 12, 2020)

Here's a pic of the upper drain bolt on a '13 Altima. View is from the front of the tranny:








Note that our "special tool" dipstick from Nissan shows that waiting till the stream stops usually leaves them about 1/2 pint low. Putting the plug back in when the stream first "hiccups" gets them exactly right.


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## AlphaBetaUser (Mar 21, 2021)

molsoncanadian said:


> Couple of questions if you guys don't mind me hi-jacking this... 1) the upper drain that you mentioned, is this the Overflow plug (14mm, iirc)? 2) Is there an average amount of time it would usually take for the ATF temp to reach 95°F to 113°F? The manual says to pull the overflow bolt at between the mentioned temps, but my generic, end-user scan tool cannot access this information (although I do see a ECT when in the TCM scan, but I think that's just the coolant temperature, because I see the same value under ECT in the ECM scan mode).
> 
> As its been mentioned here, the exact amount of fluid is crucial for this CVT. So, by ensuring the right amount of fluid via removing the overflow bolt at the right temp, one needn't worry about too much or too little fluid or how well it was filled in the past...
> 
> I was thinking of getting a laser thermometer to shoot at the trans pan to get the temp for this procedure, but if "warmed up completely" is within the range of the 95-113 temp, this would mean less expensive tools to own...


While laser thermometer works fine, I’d invest that money in a scanner capable of reading CVT fluid temperature. 

If you have an android device, this app is just perfect for Nissan CVTs: CVTz50. It can read CVT fluid temperature, and it can reset CVT deterioration date (date?!) which zeros the baseline for your next “inspect CVT deterioration date”. 

You don’t necessarily need a new android tablet or phone if you already don’t have one, you can actually install android on an old computer, purchase the app for $5 and with your current wifi or Bluetooth obd2 scanner, you’re all set! This app can read and reset deterioration date. Other apps (obd fusion, or car scanner can only read even with enhanced diagnosis feature). 
Hope it helps! 


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## molsoncanadian (May 2, 2021)

Your guys' input is greatly appreciated! It is immense, when there are folks like yourselves on this site where you come and aid other folks in maintaining their prize possessions. It doesn't just benefit us the end-users, but also Nissan the company itself. As, after seeing that there is more and more maintenance related info for the 2016+ MY arriving onto sites like this, it encourages people like myself (not a Nissan guy, but servicing family members'- too old for dealership service, Rogue) to actually look into purchasing one. As I think VStar mentioned in another post, technically these CVT's can last forever as opposed to automatics when MAINTAINED.

I know that the CVT is perhaps the weakest thing on these SUV's, now I also know (thanks to y'all), this CVT can be serviced in our driveway with the right arsenal. My biggest fear was re-filling with the wrong amount of fluid, killing a perfectly good tranny. I remember checking this site out a few years ago, with not so reputable info, so I never attempted it until I gained some confidence from Vstar's (Not to say that others' info is useless, I just happened to come across his this time around) impressive contribution here...
So yeah, thank again fellas. 🙏🙏🤘

So far, my old man's Rogue has 72K miles on it, with no CVT service ever being done. He, says he feels it jerk often at low speeds and the occasional 4k rev with not much go...
I've abandoned the Laser thermometer approach, as I was looking to spend 20 bucks on one. Later after much research, realized that results would be inaccurate with cheapie units as most of these do surface temps only and wouldn't provide the reading of the actual fluid temp behind the pan.
I am going to invest in a bluetooth OBD2 scanner like suggested above, and make sure I get ATF temp reading before attacking this drain and fill... 

Sorry for the Essay, I had to thank y'all, you cannot fathom how useful your advice is for a person like me who does their own wrenching...


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## AlphaBetaUser (Mar 21, 2021)

Very well said! VStar is a massive contributor on this forum.

Nissan should compensate his time and other knowledgeable members here on the forum for answering all questions us owners have.


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## VStar650CL (Nov 12, 2020)

molsoncanadian said:


> Sorry for the Essay, I had to thank y'all, you cannot fathom how useful your advice is for a person like me who does their own wrenching...


Nothing to be sorry about, old son. Knowledge is power in any endeavor, but no one gets it without digging in and reaching out. The world would have far fewer troubles if more people did. Consider for a moment that the knowledge you gained here will also help some unknowable number of others. Yes, they wouldn't have it if I and Alpha hadn't answered you, but neither would they have it if you had never asked. In that regard, all of us have paid something forward, and for me... let's just say that's a good day. Not to jack this thread in yet another direction, but if you haven't spent time around the business end of the car business, then you probably don't realize the fundamental unhappiness of it. To express it in a few words, no one shows up in my service bay because their car runs great and it's the best day ever. No one ever will. So when someone leaves happy, or even better-informed, that's a win. That's what warms a technician's cold wrenches, and if you haven't guessed by now, that's the real reason I spend time here.

So yes, I'll gladly forgive your essay so long as you'll forgive my soliloquy. Happy motoring, and I _mean_ that.


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## rogoman (Dec 16, 2004)

AlphaBetaUser said:


> While laser thermometer works fine, I’d invest that money in a scanner capable of reading CVT fluid temperature.
> 
> If you have an android device, this app is just perfect for Nissan CVTs: CVTz50. It can read CVT fluid temperature, and it can reset CVT deterioration date (date?!) which zeros the baseline for your next “inspect CVT deterioration date”.
> 
> ...


You really don't need any fancy diagnostic tools for measuring the CVT fluid temperature. For a simple drain/fill, it takes about 4.25 quarts of the NS-3 fluid; pour in 4 qts. Now make sure to *Fully* warm up the CVT by driving the car around for about 30 minutes or more. Now let it idle. Very important; make sure the car is *level*! Remove the overflow plug from the overflow port that's under the CVT converter case; it's at an angled position. If fluid comes out, let it continue to come out until it stops at the first "hiccup"; now the CVT is full. If no fluid comes out, then slowly pour a little of the fluid in until fluid starts coming out of the overflow port. let it continue to come out until it stops; now the CVT is full. Now drive it some more for about 15 minutes or more, then recheck the fluid level while it's idling.


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