CVT problems...???

[BigJohn767]

I just purchased an '08 Sentra SE and it feels like something is wrong in the transmission. At 35mph decelerating, it feels like it drags until it gets to 25mph and then it surges like it was released. When I touch the accelerator at low speeds the car the jumps some. Driving at 30mph, I get noise from the transmission.It also rides rougher than the truck I traded in. The dealership says they can't find anything wrong (twice). I have driven 3 other '08 Sentras and none of them acted like this one. Has anyone had any problems like this? Does the Sentra really ride rough?

[nametakennow]

First off, welcome to NICO!

As for the transmission, the CVT's are known for the surging. It has to do with how Nissan's CVT technology works. It's essentially a variable-ratio pulley system with rubber-band-like belts in it. When you get off throttle, the belt takes a moment to react in order to change the ratio, kind of like in a manual transmission car when you go from engine braking to putting the clutch in or neutral, suddenly the resistance on the engine is reduced, so you feel a surge because your rate of deceleration is also reduced. For whatever reason, some owners notice it more in their cars than others, though in theory it should affect all CVT Sentras equally.

What sort of noise do you get at 30mph?

As for the rough ride, I haven't seen any other complaints about it.

Given the noise and ride, I wonder if you have a bad motor mount. There have been some instances of problems with the passenger-side engine mount. Did the dealer check it?

[gotak]

Ride? Can't compare with the SE R having stiffer suspension but it's better then the 97 explorer i was using before and hurts more to hit bumps then my sister's Camry or my bro's 323i.

The surge yes I get that. I don't think it's a problem. I suspect it's the torque converter locking and unlocking. Above a certain speed it locks and you'll notice that this allows engine braking when going down hills. It also means the car feels more like a manual does when you let go of the gas (it slows quicker then an auto). When it unlocks that's when it starts to act more like a regular auto and that's when you get the surge as the car suddenly find it self free from the engine RPM and can coast better.

As for the noise umm I don't get that but I do think my CVT is different from the unit you get though. I do get a rumbling noise from the intake resonators when the CVT is at top ratio cruising around at city speed. But your 2.0 don't have the same intake so it shouldn't be that noise.

[livinloud98]

my car does the same thing with the engine braking and then releasing its normal, the CVT will whistle every now and then, and the car is pretty tight, so you will feel bumps. trucks have loose suspension so you wouldnt feel as much in your old car

[djtorello]

Im

I just purchased an '08 Sentra SE and it feels like something is wrong in the transmission. At 35mph decelerating, it feels like it drags until it gets to 25mph and then it surges like it was released. When I touch the accelerator at low speeds the car the jumps some. Driving at 30mph, I get noise from the transmission.It also rides rougher than the truck I traded in. The dealership says they can't find anything wrong (twice). I have driven 3 other '08 Sentras and none of them acted like this one. Has anyone had any problems like this? Does the Sentra really ride rough?

Im confused. There is no 08 sentra SE. the options are: 2.0, 2.0S, 2.0SL, 2.5 SE-R, and 2.5 SE-R Spec V.

Assuming you have the SE-R, what you feel is normal. You also need to understand, the 2.5L's are the Sport Version of the basic 2.0L Sentra. Which includes stiffer springs, and larger rims with thinner tires. Making the ride a bit more harsh the the 2.0L, but what you get in road feel, gets compensated with better stability, and better braking. If you notice, our brakes are far superior to that of the 2.0L version.

YOu need to be careful when trying to compare Sentra's as a whole, as the upper models are a big differance then the lesser models.

As for any odd noises, you will get a high pitched squel like noise, This is air passing the Throttle Body butterfly. If you get more of a Deisil sound? Thats the intake track, its specificly designed to make a more powerful sound, then the base 2.0L.

[BigJohn767]

Sorry about the misinformation...it's an S model. Don't know where I got the E from!!!!

Thanks everyone for the info. It just feels funny decelerating between 35 and 20. Kind of drags but I will try to get used to it.

NOW the tire pressure light came on and won't go off. Oh well, back to the dealer! I might have one of those lemons here......

[djtorello]

Sorry about the misinformation...it's an S model. Don't know where I got the E from!!!!

Thanks everyone for the info. It just feels funny decelerating between 35 and 20. Kind of drags but I will try to get used to it.

NOW the tire pressure light came on and won't go off. Oh well, back to the dealer! I might have one of those lemons here......

Well the TMPS light might be on simply from a change in air temp, as the air in your tires expand and contract, Or you have a leak.

Check all your tires and make sure they are at 35psi. at 33psi the light comes on. If you are low on air, top it off, then drive up to 40 mph. Anything lower then 40mph and the light will stay on. 40 mph is the computers reset speed.

If the tire doesnt have a leak, and you are still losing pressure, it can be one of 2 things.

1) your Rim is bent just enough that you will lose air under certain driving conditions, like hitting curbs or bumps.

2) it could be the TMPS on the rim. It has a small gasket to prevent air from placing by and out the tire. That where my problem lies. My dealership has the part on backorder, so i just fill the tire up every 2days or as needed.

[jonthapianist02]

i don't know if u got ur problem fixed yet or not.. but i had the same problem. had a bad motor mount on the passenger side... took nissan a week to replace it. they gave me a lame excuse about nissan having a "bad batch"... then it thru off my catalytic heat sheild so when i shifted, it knocked. they fixed that too.

[kerrton]

Has anybody got close to 100,000 miles on their CVT yet? It would be nice to use as an example to those who believe that the CVT won't have the long term durability of a conventional. Also, have you had the CVT fluid changed over that time? Some say it never needs to be changed, other dealerships recommend quite short intervals, not sure why the inconsistency?

[nametakennow]

Check the manual and go by that for changing interval.

I doubt anyone has put 100k on one in the 2 years they've been out.

[08sentra2.0sl]

also

Sorry about the misinformation...it's an S model. Don't know where I got the E from!!!!

Thanks everyone for the info. It just feels funny decelerating between 35 and 20. Kind of drags but I will try to get used to it.

NOW the tire pressure light came on and won't go off. Oh well, back to the dealer! I might have one of those lemons here......

also for the tire pressure make sure they are all with in 2psi or it will go off. What a nissan tech said, then drive for awhile

[Tedf44901]

68000 miles on my 03 Murano. They say I need a new CVT. $6200!!!

[marlin29311]

The 03 CVT is much different from new redesigned CVT's being used in the 2007+ models from Nissan.

Has anybody got close to 100,000 miles on their CVT yet? It would be nice to use as an example to those who believe that the CVT won't have the long term durability of a conventional. Also, have you had the CVT fluid changed over that time? Some say it never needs to be changed, other dealerships recommend quite short intervals, not sure why the inconsistency?

The NS-2 fluid was designed to withstand about 90k miles under normal conditions.

[kerrton]

[QUOTE=nametakennow]First off, welcome to NICO!

As for the transmission, the CVT's are known for the surging....... For whatever reason, some owners notice it more in their cars than others, though in theory it should affect all CVT Sentras equally.

QUOTE]

I feel that the reason it isn't the same in each vehicle is because it is heavily dependant on driving style. If you drive conservatively it is much more noticeable than if you drive agressively. I'm also pretty sure the surging is caused by the torque converter locking on acceleration and unlocking on deceleration. I really don't think the current CVT models are like your "rubber band" description at all. The steel belt and pully's mesh seamlessly and in my experience there is no "rubber band" effect, only surging caused by the torque converter. I have a Rogue with the same 2.5 engine and identical CVT, and I know a lot of this is related to driving style.

[nametakennow]

To an extent, the torque converter being the culprit makes sense, particularly with a CVT, as the idea that the CVT is putting the engine in a specific point in the power curve, so when the torque converter engages the engine and transmission together, the effect ought to be more noticeable.

However, the whole point of a torque converter in automatic cars is to be able to modulate that engagement. It could just be that there's not quite enough slip in the converter to make the engagement smooth, but to an extent, at least, the fact that the transmission utilizes belts means that there will be at least some flex in that part of the system as well. If the belts didn't flex, they'd be liable to snap too easily under power.

No matter what the actual cause, however, the point stands that the engagement/disengagement with the CVT has been an issue with all Sentras, and most likely any of Nissan's CVT-equipped vehicles.

[kerrton]

Good point.

When you say "this has been an issue....", do you mean just in terms of the driver experience/preference, or do you mean that this is an actual problem with the CVT that could result in pre-mature wear etc.? I assume you label this a problem only in terms of how intrusive drivers may find this feature to be and go against their preference, but since this is the way the CVT was designed to operate it would not constitute a problem the way a service department would define it?

[nametakennow]

Insofar as I know, it's purely intrusive and not an actual physical problem.

That said, I can't imagine that flex in the belts and/or an overly harsh torque converter engagement would be good for the transmission. Not having actually experienced it myself (I have an '01 with a 5spd, after all), I can't attest to the degree to which it is noticeable as I'm sure you can. I wouldn't think it would be excessive to the point of obviously wearing on anything, otherwise I'm sure the complaints would be more common, but an adjustment by Nissan for added smoothness certainly wouldn't hurt.

[sentrahead]

I also have a slight grumble on the passenger side of my 07 sentra with cvt, it could be an engine mount sound. I also experience the delay at throttle off. I also have a very slight whinning noise from the engine all the time, less noticable at higher speeds, I can hear it at idle, goes with engine speed in or out of gear. reminds me of the torque converter that shredded itself on an old dodge caravan, but much lower volume, cant hear it with the air conditioner on. Does anyone else have this small sound?

[ABNRML4U]

I wish you the best on your Nissan Man.

[NickJK]

Wow, haha. Everything you said sounds like what I told my service department verbatim...

I was having the same issues. The dragging feeling around 30ish, then it downshifted and ran a little smoother at about 22mph..

Well, initially they told me nothing was wrong. But, after going back 3 times they gave me a new CVT. Everything was fine.. And then in about another 13k miles, I'm driving in a hilly part of town, and I begin to hear a strange, high-pitched whirring sound. I drove to AZ with the noise the entire time. Took it back to the dealer, they gave me ANOTHER new CVT. First CVT replacement was at near 40k miles, 2nd was near 50k miles. Everything seems to be working fine now..

And as for rough idling, I have never had a problem with that. I have had the occasional stutter, where the engine seemed to drop in RPM's for a split second, but then came right back up..

[crownautotrim.com]

Mine does the same thing around 30mph, its just a trait/quirk that these cars have. I recently got an extended warranty thing that says Nissan will cover the CVT to 100K.

[l0c0tez]

My 2009 sentra is coming up to 100k. I have noticed a "gear engaging-like" sound whenever i initially accelerate or brake hard. i played around with my car and could duplicate the sound while sitting at a stand still switching the shifter from Drive to Reverse...and back and forth. As it engages into gear that "cling" or "ping" or whatever you want to call it can be heard. i can even duplicate it when i physically climb under the car and twist the drive shaft back and forth. It makes sense if the torque converter is involved. I hope its not something that i will be having an issue with after i hit 100k. As far as the drivebility goes, i have no complaints....other than that annoying sound.