Cooler for 2018

[D1dad]

Anyone installed an aftermarket cooler in their rogue 2018? Any tips and instructions would be helpful and also what cooler should I use? I’m also in a cold climate (northern Ohio) so I don’t want a situation where the transmission runs to cool either. Also, do I need to add more fluid to accommodate the cooler itself and or flush the cvt?

[VStar650CL]

I really like the Hayden 69x series, they have a bidirectional H-Valve and a 160F crack temperature very suitable for CVT's. You can also steal the cooler off a junkyard R52 Pathfinder, those have a 140-something crack temp and are very hefty.

Not to put in a free plug, but it sounds like you're a candidate for one of my beehive-killers. One of my customers with a Quest in Idaho tells me he routinely runs 15~25F cooler climbing mountains just like the ones you traverse in WV:
https://www.ebay.com/itm/144840813130

[VStar650CL]

PS - There's not usually enough fluid capacity in a small-to-medium cooler to necessitate adding extra fluid. However, back-flushing the existing heat exchanger while the hoses are off would be a very good idea.

[D1dad]

Thanks vstar. What cooler should I order? You didn’t exactly give me the full #. Does this cooler have a built in thermostat so I can heat up the fluid during the cold months here in the rust belt?

[VStar650CL]

The 697 is what I have on the wife's Altie, it's probably also appropriate for your Rogue. It has a 160F internal bypass with a very clever (patented) reed valve setup which makes it bidirectional, either tube can be inlet or outlet. It will still care about orientation, you should follow Nissan's side-tank pattern of mounting it sideways with the inlet lower than the outlet. That will bleed any bubbles from startup cavitation back into the pump. The lower/driver tube on the beehive is pressure and the upper/passenger is return. You will need a couple of brass adapters for the lines in addition to the cooler, Hayden uses 3/8" nipples and the beehive nipples are 5/16". On the Altima (side-tank setup) I found the easiest install was to put everything on the pressure side of the radiator and leave the return line completely alone. Your Rogue has a bottom tank, but I think that will still give you the easiest arrangement. When flushing the heat exchanger in the radiator, make sure to back-flush through the return port. The cross tubes in the cooler are very tiny and forward flushing won't do a thing. Check out these pics, you'll see what I mean:
post6848395.html?hilit=heat%20exchanger#p6848395

[D1dad]

Thanks for that. So mount the cooler sideways, feed the cooler from the bottom and back flush the existing cooler? What do I use to back flush the cooler? Sorry for all this, but I’m having my local guy do the job as I’m crazy busy at work right now. I’m catching flights to and from Tampa weekly and barely have time to even mow my yard and wanna give him as many pro tips as possible. He’s a 30 year mechanic so I trust him, he just doesn’t do these on Nissans everyday.

[VStar650CL]

They sell CVT cooler flush in a can, but frankly, ordinary alcohol and compressed air are fine on a car with fairly fresh fluid. I know you take good care of your hardware, so gum cutter probably isn't necessary.

[D1dad]

Got it and yes I do. My mechanic yesterday commented that I’d be the guy he’d wanna buy a used car from. At near 80k I’ve performed 12 cvt fluid changes, 4 transfer case and rear diff services and just replaced all the brakes and rotors the 2nd time. I did a double drain and fill yesterday on the cvt with eneos eco (love that stuff) switched the diffs over to motul ester 80-90 and switched the brakes over to Ebc (red stuff) rotors and pads. I could make this thing stop on a dime if needed. Brake fluid gets changed when my digital tester shows it needs it, which is well beyond Nissans 20k. My 21 Altima has only had 1 cvt service and new ebc rotors and pads and a brake fluid flush at 30k. Although I did ditch the stock Hankooks which sucked at 25k for some Michelin pilot sports. The end result is my wife not noticing a dam thing I’ve done to her car. As long as that sucker goes from zero to the speed limit as fast as possible, she’s happy.

[VStar650CL]

The end result is my wife not noticing a dam thing I’ve done to her car. As long as that sucker goes from zero to the speed limit as fast as possible, she’s happy.

Happy wife, happy life. Love it!

[D1dad]

I got the same one on order Vstar. What temps does your Altima run at now? I have a place in Myrtle beach and it would be nice to see temps well below 200 running through the mountains.

[VStar650CL]

I got the same one on order Vstar. What temps does your Altima run at now? I have a place in Myrtle beach and it would be nice to see temps well below 200 running through the mountains.

Lola has a CVTsaver on her and the tallest mountains around here aren't very tall, so I don't think I can give you an analogous assessment. I can tell you on a hot summer trip to Fort Worth I had CVTz50 on her the whole way, she never topped 175F even in 100F ambients. Climbing Mount Nebo or Mount Petit Jean she never gets much past 185F, but those are short, sharp climbs compared to the long highway grades you're traversing. Very steep, but not very lengthy. She used to hit near 200F going up Nebo with a Hayden 512, before the 697 and the CVTsaver.

[VStar650CL]

PS - I've found the real problem with hills to be that the cooler can't dissipate as much heat on the downhills as the transmission accumulates on the uphills. So steep, repetitive grades are a killer. The biggest reason is that the beehive never stops dumping heat into the fluid, and that's trouble when the engine is working hard. That's where the CVTsaver makes a huge difference, cutting off the beehive flow so the cooler can work efficiently. Here's the real life performance doing a hot transmission simulated with a deliberate Torque Converter stall:
post6843611.html?hilit=CVTsaver#p6843007

[D1dad]

I actually had somewhat of the opposite going through the blue ridge mountains last year. There was one stretch where I was on a steep grade for around 30 miles, I topped out at close to 220. As soon as I reached the top the temps started dropping and ended up in the 195 zone. I’ve tracked this and came to the conclusion that the cooler in the radiator will keep the cvt from welding itself into a big hunk of aluminum, but not much more.
My cvt temps average about 10 degrees warmer than my water temp. I just hauled a 30 ft construction trailer for my son with my powerstroke Saturday, fully loaded, and my trans in that beast hit 210 while laying into the throttle. I used Lubegaurd cvt fluid on this last trip to Kentucky, which has a higher viscosity and the temps were higher than with eneos, so thicker isn’t better here. I did a double drain and fill when I got back to rid the cvt as much as possible of the Lubegaurd.
Of course it got cold again in Ohio so I can’t see if it helped. I also did a coolant drain and fill with zerex Asian coolant last fall so maybe that contributed as well? Although the water temp has always been 180-190 so I doubt that played a part.

[VStar650CL]

Running more than a 50-50 coolant mix can purportedly drive up the CVT temperature because the heat transfer characteristics of glycol are crappy compared to water. However, in my experience, the presence of the beehive makes that a push under most conditions. Unless the fluid goes above coolant temperature, the beehive is pumping heat into the transmission instead of dumping it. So while too much glycol hinders the efficiency of the heat exchanger at cooling the fluid, it also hinders the beehive's ability to heat it up. The bottom line is, I don't really think your fresh coolant would have affected things much, even if you went overboard on the mixture.

One other thing I noticed in the course of experimenting for the CVTsaver is that under load, the SUV's and crossovers all ran higher radiator outlet tank temperatures than the sedans. I can only speculate that it's a function of airflow deriving from engine box layout, but I found it true across the board and across powerplants. V6 Muranos, Pathies, and Quests all ran hotter outlets than Maxes, I4 Rogues all ran hotter than Altimas. The beehive is heated by the cylinder head loop and not the block, so in equilibrium that may actually be lower, but since the outlet tank temperature directly governs how much heat the exchanger can dump, some of what you're seeing seems to be baked into the cake.

[D1dad]

It was a premix jug of coolant. From what I’ve gathered, pentosin seem to the oem producer for Nissans coolant, so I wouldn’t think valvoline/zerex would be of any less quality. I can say for sure that the thicker lubegaurd cvt fluid gave me higher cvt temps than oem or eneos ever did, so thicker fluid isn’t necessarily better in a cvt. I still have about 5k left till the extended warranty expires and don’t know if installing this cooler would cause an issue should things go south before then? so I may wait.

[VStar650CL]

In a perfect world a cooler wouldn't affect the warranty unless it was installed improperly, but the world isn't perfect. It will implicitly shift the burden of proof from Nissan or the warranty company to you. I'd say wait the 5K.

From a heat standpoint, thicker fluid definitely isn't better in any belt-driven CVT. When the TC is locked, the greatest heat-producer is shear in the fluid inside the pump and where the belt contacts the pulleys. Fluid with higher resistance to flow will cause more of that, not less. It might (arguably) be better for the bearings and gears, but positively not for the belt.