[JukeyJukeJuke]

Fastreligion thats great great info. Couple thoughts and questions as I read that.

First, your "too big" cvt cooler could have has a bypass and thermostat valve (they are common) and it would only send coolant to the big cooler when needed (at 180f or whatever the thermostat is set for).

How did you feed the cooler on the Juke you sold at 130k, with the four-barb beehive?

Do you think my juke temps are resulting from older fluid? Or is normal wear showing in higher temps? 2011, has about 150k mostly easy miles on it.

What did you use for the pump on the insane Juke?

 

[FastReligion]

I was trying to make a product to sell, and thermostatic by-passes ad a LOT to the cost of the system and complexity. Not everyone knows how to tell of one is working right or not. So It had to be simple. You also have to deal with air at that point too. When you shut off a CVT the fluid will drain out the hoses and back into the CVT if the cooler is mounted above the adapter. This is fine when you just start the car back up, as the CVT self bleeds in a few seconds, and your not driving at that point. Now, if your driving the car and the thermostat opens to allow CVT fluid into the cooler, the CVT now has to burp that air in the cooler while it is already moving, which could cause aeration to occur in the fluid, making it more likely the CVT pickup will get bubbles in it and cause issues. Also: Shocking the CVT with ambient air temp fluid on the initial opening of that thermostat is bad too, the internal temp sensor for the CVT could see a dramatic drop in CVT fluid for a second and trip a code or limp mode, thinking something is wrong. You want it all to heat up and level off organically. There is a reason almost no affordable OEM's use thermostatic systems in regards to oil or hydraulics, too many potential issues. You jsut have to size the cooler to maintain a set temp in set circumstances.

At 150miles on the oem cvt, that CVT is just about done. Your lucky it has lasted that long. Highway driving is what kills a CVT. its a long duration of continued torque. Thats why most people get CVT limp mode on the highway, and not some back road. The CVT makes the most heat on the highway.

On the Insane juke I ran a self-priming pump designed for oil with a thermostatic switch with two lines directly into the modified CVT pan. IT was both overkill, and never did what it was meant to do as mentioned above. Your adding a lot of complications with a system like that.

All my jukes, my current one included, just use the OEM 4 barb beehive system. Ive sold hundreds of them, installed dozens of them, and never had any issues.

 

[JukeyJukeJuke]

all very interesting. still dont know why my CVT is running so warm tho. Looks like from reading all this, boils down to wear, old fluid.

btw this all started when it surprised me with limp mode last July after towing a boat for 100 miles all highway, and then I researched it. after that the amazon beehive and cooler went in with the Hayden 677 cooler and I think 1/4" lines. The other day it was kinda warm so i said "let me check the CVT", plugged in the OBDII and was shocked to see 130c temps. The question really is "why", wear, or could simply old fluid do it?

amazon.com/gp/product/B07DS7QBWR

https://www.amazon.com/gp/product/B000C3F3SO

 

[FastReligion]

old fluid heats up faster and loses its viscosity faster, and at that many mileage, wear is causing it too.
That cooler is WAY too big, on a fresh CVT that will potentially cause CVT temp issues.

 

[JukeyJukeJuke]

That cooler is WAY too big, on a fresh CVT that will potentially cause CVT temp issues.

I assume you mean it would keep a fresh CVT too cool? I been working on cars and modding for decades. But it stumps me how a too big cooler could allow 130c CVT temp on a normal (ok I drive slightly spirited) highway drive.

Wish Nissan had done CVT RIGHT to begin with...

 

[FastReligion]

it comes down to the flow rate, the fluid flows fairly slow, and cooler like that can cause it to flow even slower, which means more time to cool off, which is the point. Thats why i run tube and fin, it does not obstruct flow at all, so the fluid can pass through like it normally would in the oem cooler available internationally. But we are stuck with what we are stuck with in regards to the CVT. With all the CVt testing ive done i have found age means heat, old fluid means heat. no cooler will fix that.

 

[JukeyJukeJuke]

If I ever need one, is this option better than OEM? $2795

Nissan CVT Transmission for Sale, Remanufactured Rebuilt

 

[FastReligion]

I only ever install OEM reman units. They come with a built in warranty. And that one in the photo is a V2. you can tell from how the front of it looks.

 

[JukeyJukeJuke]

where would I get a OEM reman? and what do those cost?

 

[Macgyver]

If you want to do anything. Tho it is only short term. Change your CVT fluid. Buy 6 quarts and get it changed.

 

[FastReligion]

where would I get a OEM reman? and what do those cost?

the dealership. About $2700.

 

[JukeyJukeJuke]

OK big clue today after a fairly long drive about 60 miles each way. First half CVT temps stayed at or below about 110. I checked the cooler out front and the left side was warm, most of it was cold.

On the way home, temps slowly rose to 128c. at 70+ MPH at times. Outside temps in the upper 70's

When I got home I immediately checked the cooler and it was STONE COLD, as in, no flow.

CVT was at that point, 127c. I checked the CVT dip stick (my 2011 has one) and it looks quite a bit over the hash marks, very clean almost clear fluid.

Could overfilled CVT cause the cooler to NOT get any flow?

This is VERY weird. BUT I'm determined to get to the bottom of it, with help from here of course!

 

[FastReligion]

No, most CVT's in the Juke are actually over-filled from the factory, theres dozens of posts about it. Make sure you checking the dipstick when CVT fluid temp is ~114F, otherwise it will not read exact (According to FSM) The engine must also be on when checking or you will get a false full reading. I am telling you its the CVT being bad. If the cooler is not getting any flow, you may have a kinked line, the cooler is clogged, or the filter element behind the beehive was damaged and has caused one of the two other issues. The CVT fluid that goes into the beehive has already passed through the CVT itself, so if there was NO flow, the car would not be moving.

 

[JukeyJukeJuke]

more good info. the cooler was brand new not likely clogged. I had them put in a brand new filter under the bee hive that I had sourced and fairly certain ni kinks.

as to the no flow - no moving idea, as far as I could tell looking at the beehive, the flow is shared between the beehive intercooler section, and there are open ports to the extra barbs for the front cooler. if the cooler lines were kinked, it would just behave as a stock beehive, with all flow just going through the beehive?

bottom line is somehow the cooler is NOT flowing, at least I should fix that, and soon as I find the correct procedure, change the CVT fluid.

suprised that the CVT is running too warm with NO other issues, no whining, works fine. and that really means it's bad?

 

[FastReligion]

whining is just a symptom, hell, healthy CVT's whine. Just because you dont have a runny nose, does that mean you dont have the flu? Overheating with a cooler means the CVT is bad...cant really say it any other way... As for behaving like a stock beehive, yes, it would if the system where clogged only in the cooler itself. Which would lead me back to saying theres and issue with the cooler or lines.

You have a CVT that overheats. That's already saying it needs to be replaced...
Adding a cooler to a CVT that already overheats just buys you a few thousand miles...
You have a CVT cooler that works inconsistently, that tells me the cooler design is not working.

These are things I have already said. Best of luck to you!

 

[JukeyJukeJuke]

You have a CVT cooler that works inconsistently, that tells me the cooler design is not working.

OK thinking bout that, how could the fluid NOT be pumping thru it sometimes. I have to investigate that.

Assuming I wanted to try a new reman CVT can u point me to a reliable source for those? There are a lot of options out there no idea what is good or not

thanks!

 

[FastReligion]

it should flow through it all the time. Again, Ive installed dozens of CVT coolers, and they are always warm on the face. Ive tested 5 or 6 different set ups, all of them hot across the face.

Nissan is the only place you should ever source a transmission from. You know they used oem parts to rebuild them, and you get a warranty with it.

 

[pboglio]

Aeration and cavitation is happening because of fluid overfill, don't overfill or overheat and it won't be a problem. The size of oil cooler you would need to dissipate the heat would need to be very large. It's easier to make a more efficient oil/water heat exchanger that uses high water flow rates, to make the exchange with the radiator. I'll be using a Laminova oil/water heat exchanger mounted at the base of the radiator with radiator coolant flow running thru the core, then a couple of CVT oil feed lines coming off a custom oil filter/thermostat adapter mount going in the stock beehive cooler location. The cvt vane oil pump will drive the necessary flow without the need for an external pump. This has enough heat exchange capacity to keep the CVT oil around 98-100 *C if the coolant is running at 85*C, even at power levels past 330 h.p. The thermostat then bypassing the cooler when it's not needed. IMHO all these other external oil coolers are a waste of time, the CVT thermal heat dissipation levels are massive at full power, almost equal to the engine's waste heat thru the cooling system.

 

[JukeyJukeJuke]

so you havent actually done that yet, when will u have it done and tested?

as to aeration, u think that may be why my cooler is not getting any CVT fluid? I'll warm it a little and drain it tomorrow to within the hash marks. Fortunately I have a 2011 with a CVT dip stick. I wonder how to check level on the ones without a dip stick?

 

[FastReligion]

Aeration and cavitation is happening because of fluid overfill, don't overfill or overheat and it won't be a problem. The size of oil cooler you would need to dissipate the heat would need to be very large. It's easier to make a more efficient oil/water heat exchanger that uses high water flow rates, to make the exchange with the radiator. I'll be using a Laminova oil/water heat exchanger mounted at the base of the radiator with radiator coolant flow running thru the core, then a couple of CVT oil feed lines coming off a custom oil filter/thermostat adapter mount going in the stock beehive cooler location. The cvt vane oil pump will drive the necessary flow without the need for an external pump. This has enough heat exchange capacity to keep the CVT oil around 98-100 *C if the coolant is running at 85*C, even at power levels past 330 h.p. The thermostat then bypassing the cooler when it's not needed. IMHO all these other external oil coolers are a waste of time, the CVT thermal heat dissipation levels are massive at full power, almost equal to the engine's waste heat thru the cooling system.

So, your saying all the people who have had their overheating CVT helped by installing a cooler, including the OEM nissan one are wasting their time? Sorry, but the real world testing by hundreds of people and the data myself and dozens of other people have accumulated sort of prove they work. Transmission coolers are used on all kinds of transmissions. The beehive is too small to be able to transfer heat effectively using coolant. In fact, according to diagnostics I did at nissan, the beehive is actually there to help stabilize cvt fluid temps, but will not prevent the temp from rising as milage increases. On the rogue for instance: Older ones came with the Jukes style beehive, and for CVT overheating NISSAN had us install a OEM cooler as a "fix" that was basically the cvt cooler everyone installs on their jukes. As for 330 hp, no cvt Juke will ever see that power level, so no one can confirm anything about that heat. I can confirm that at the CVT limit of 267ish hp the size cooler you need with extra fluid to help maintain a good temp during WOT pulls is very large. Your system you are making osunds interesting, ad more than likely will maintain decent cvt temps, but as the CVT ages, there is nothing you can do to prevent it from eventually failing in one of several ways.