I was on the highway today going about 60 mph. When I would accelerate a little and the rpm's were at 2,000, the car would shake. If I accelerated more and the rpm was at 3,000, it would no longer shake. I did this a few time over the course of 5-10 minutes. After that time, it didn't happen anymore. Very weird. Has this happened to anyone before?

update: 2012 Sentra, 125k miles.

First, see if there are any codes in the TCM (transmission controller). There may not be any, since a '12 won't have "judder detection" in the CVT firmware like later models, but you should check anyway. When the engine is lugging along at low RPM with the Torque Converter locked, accelerating lightly won't unlock the converter and puts maximum torque load on the CVT belt. That's when judder (CVT belt slip) is most likely to occur. Judder can be a come-and-go occurrence in the early stages, but if that's the problem it will definitely get worse over time.

What kind of mileage does the car have? Has it gotten regular transmission fluid changes?

The car is a 2012 with 125k miles. I last changed the CVT fluid at 68k and I plan to change it again this weekend. The check engine light isn't on but I'll scan for codes anyway.

Could it be the motor mounts?

Rtraveler wrote: ↑

Tue Apr 05, 2022 6:23 am

The car is a 2012 with 125k miles. I last changed the CVT fluid at 68k and I plan to change it again this weekend.

That's an awfully long fluid interval unless you live in Kansas and drive like grandma. Otherwise, I can pretty much guarantee your fluid is shot. Most people should D&F about every 30K, or sooner if you're a real leadfoot. The wife and I both are, so our '13 Altie gets changes at 20~25K. You don't need to blow up your budget with OE NS2/NS3 fluid anymore, the aftermarket fluids have caught up with the miscibility and film strength issues they used to have. I can personally recommend Eneos and AMSoil by way of my customers, I've seen very good results and zero issues.

Rtraveler wrote: ↑

Tue Apr 05, 2022 6:23 am

The check engine light isn't on but I'll scan for codes anyway.

The older CVT's can do a lot of goofy stuff that doesn't light the MIL, particularly for over-temperature protection. The MR20 CVT's don't have coolers, either, so they can run hot routinely and never give you the slightest clue until one day the TCM says, "Too hot, I'm shutting you down." You end up parked for 15 minutes and then the car is fine, no MIL, no nothing, even with a scanner. Only a dedicated CVT monitor app like CVTz50 will show you what's really going on.

Rtraveler wrote: ↑

Tue Apr 05, 2022 6:23 am

Could it be the motor mounts?

Possible but unlikely. If it is the mounts, then there must also be something in your engine's state of tune that's making the bad mounts need to work too hard. Mount problems rarely show up when cruising, usually they show up during R-D-R-D shifting or on hard accel/decel.

I was just following the scheduled maintenance which is 60k miles for CVT fluid but I get your point, it can't hurt to do it every 30k miles. Thank you for your input.

"For vehicles with a CVT transmission (cube, Murano, Altima, Altima
Coupe, Maxima, Rogue, Sentra
and Versa), replace the fluid every
60,000 miles"

Sadly, what Nissan recommends for CVT service has never been what's best for the car. Nissan isn't the only guilty party, all OE recommendations for CVT's are largely based on getting the car past 100K miles with minimum official cost of ownership. Since a D&F with genuine NS3 is cost-equivalent to about 4 oil changes, that's a chunk. Believe it or not, when CVT's first came out, Nissan and some other OE's actually had the chutzpah to advertise "lifetime fluid". That ended in a hurry (badly), but the crappy maintenance recommendations didn't (and still haven't).

I see dead CVT's literally every day of my working life, and I can tell you with few exceptions, they all die from old and burnt fluid. When you consider how a CVT works, it's easy to understand why. Instead of sacrificial clutches like a conventional A/T, a CVT has a steel belt riding on a pair of steel pulleys. Steel riding on steel means the mechanism is entirely dependent on the quality of the fluid. Film strength is the only thing keeping those parts separated. So when the fluid fails, so does the trans. Simple as that.

Thank you for the explanation. I will do it every 30k miles going forward. I'm trying to get to 200k miles. I figure it might take 4-6 years but that's my plan so I want this car to last.

You're most welcome. You can reach that and more if you take care of it. We have an old Murano in our shop that will go past 500K sometime next year on the original CVT. The vulnerability of the CVT to bad fluid is also it's strength when you keep the fluid fresh. No clutches or bands, so there's nothing to wear out. Perpetual motion.

In your case, since a D&F only voids about half of the old fluid, I think I'd recommend giving it a couple of D&F's in quick succession to get at least 3/4 of that old stuff out. Don't let anyone tell you about "leaving old fluid alone" like a conventional A/T, either. It doesn't apply. With almost no clutch material, CVT's never make "ATF soup" like a conventional trans, so the rule for worn out fluid is simply, "Get it the heck out." The only other caveat is, never overfill. Topping-up extra is another bit of conventional A/T wisdom that doesn't apply to CVT's. With CVT's, overfilling is destructive, so keep it to the right level and not above.

Hope you reach that 200K, and happy motoring!

The right amount is 4 quarts, right?

Go by the stick, or measure what you remove and replace the same amount. Never just throw a fixed amount at it, they all take a little more or a little less. Underfilling is harmless, even by as much as half a quart, but half a quart overfull can kill a CVT in 1000 miles. The level is one thing you never want to screw around with, it needs to be right.