CVT Surge

[kerrton]

I'm surprised that no one has started a thread on the "CVT surge". I don't remember it being that intense early on when I was test driving, but it sure is noticeable now. It's particularly bad if you drive conservatively with a light foot and once the car is warmed up, if you push very gently on the accelerator from a stop all of a sudden around 10km/hr the vehicle will surge forward as the torque converter locks up. If you coast into a stop light at around 20km/hr the torque converter unlocks and surges you forward, and there have been times when I found this to be almost dangerous, because the forward surge is significant.

If you drive harder on the accelerator and hard on braking this isn't barely noticeable at all, it only happens when driving with a light foot. I don't like it and honestly it makes me drive a little more aggressively to prevent this from happening, and like I said it seems a little dangerous at times. The CVT is supposedly so smooth, but that isn't entirely accurate and I can't say I'm impressed with the surging.

Anyone else have thoughts on this, do you notice it, does it bother you?

[philipa_240sx]

Nope, don't notice it. Mine seems very smooth.. either that or I do not pay attention.

Curiously, a good friend of mine has a Mini Cooper ('03 or '04?) with the CVT. They have had so many issues with driveability. The most disturbing was a tendency to gear down too quickly when braking... to the point where you would be flung forward in your seat. It made it difficult to drive the car smoothly. BMW was releasing new software for the CVT on an almost monthly basis to fix the problems. I guess BMW finally gave up as the new Mini's now use conventional automatics.

[kerrton]

Really....I noticed a lot of Sentra and Versa owners reporting it, all feel it is a normal characteristic of the CVT, but I still feel it is heavily dependant on driving style......anyone else?

[Couz]

I feel the surge when I start the car and get going after I stopped the car for a short period of time, like a gas fillup or going into a convenient store for a few minutes.

When the car is warmed up and you start it again it picks up or surges right away but settles down after.

Other than that I don't notice it much, only an odd time when I'm cruising.

[maverick_rogue]

Hi

I have noticed very slight (and very much manageable) surge when Torque Converter engage or disengage while stopping at a signal or starting at it. Something similar to what we notice in a manual Shift transmission while changing gears or applying clutch.

I cross Twenty Four signals on an Eight Mile drive from home - office, so probably I am used to it by now if it exists. I too am a conservative driver though and drive with a light foot ( Driving in 35 MPH Zone with cops on every corner helps).

Edit: I usually wait for Thirty Seconds after starting the engine before I press throttle or until engine temperature indicator shows bottom two blocks (Sorry don't know how they call it technically). Do you guys do the same ?

Modified by maverick_rogue at 4:27 PM 5/14/2009

Modified by maverick_rogue at 4:27 PM 5/14/2009
Modified by maverick_rogue at 4:28 PM 5/14/2009

[ahhbeebee]

I consider myself to have a pretty light foot, never noticed it.

I typically try to pay high attention, but I'll have to double check next time I'm driving.

[NismoPhan]

I don't think I've ever noticed it. One thing I do notice is the low gearing on inclines. I live on a pretty steep hill and when I coast down the hill the CVT really does any and all braking for me. Good or bad, I haven't decided yet.

[kerrton]

Well maybe a better way to describe it is the same sensation as a conventional transmission gearing down, that little bit of a kick when you're decelerating towards a stop, presumably as the torque converter unlocks......

[Pescakl1]

I have noticed very slight (and very much manageable) surge when Torque Converter engage or disengage while stopping at a signal or starting at it. Something similar to what we notice in a manual Shift transmission while changing gears or applying clutch.

Ditto.

I am really light on the gas pedal (never over 1500rpm at the start (when engine warmed up) hoping one or two seconds later the engine will go down to about 1200 rpm as it goes in high gear) and no surge I noticed in my part.For deceleration as I usually cruise to a stop or a red light (not pleasing my followers but who cares?) with fuel consumption reading 0, as soon as the engine reaches about 1000 rpm, the torque converter is disengaged as the engine will stall below that level (when engaged, idle is at about 650 rpm), and fuel is reapplied and that gives a feeling of free wheel (before you had some engine braking as the rolling keeps the engine running). That may be that feeling you describe as surge, but it is more free wheel (no more engine braking) as you will pull the clutch on a manual car,

[maverick_rogue]

Hello

"with fuel consumption reading 0"

Where do we get this reading? I know MPG reading but did not find fuel consumption reading. If its on Odometer that will be great!!!

[Pescakl1]

Sorry, it is on my scangauge (LHK and LPH readings).

I have an SL Base model so no On Board Computer for me.

[SewinSew]

I haven't noticed any surge in my Rogue. I also drive with a light foot. I have only had my Rogue 1 month, with not a lot of miles behind me. I had a 07 Altima with a CVT before the Rogue. The CVT was a definite must have when I was looking at new car. I never noticed any surge in the Altima. I had driven it for two years in different driving conditions, short trips and long.

[philipa_240sx]

Sorry, it is on my scangauge (LHK and LPH readings).

I have an SL Base model so no On Board Computer for me.

Pecakl1 is using a ScanGauge II, it's a diagnostic tool that plugs into the car and gives all kinds of information including real time fuel consumption.

You can read more here: http://www.scangauge.com/

[kerrton]

I haven't noticed any surge in my Rogue. I also drive with a light foot. I have only had my Rogue 1 month, with not a lot of miles behind me. I had a 07 Altima with a CVT before the Rogue. The CVT was a definite must have when I was looking at new car. I never noticed any surge in the Altima. I had driven it for two years in different driving conditions, short trips and long.

Ok, for everyone who doesn't notice a "surge", do you notice a bit of an impact like the feeling of a conventional transmission shifting gears, when you first accelerate slowly, or upon declerating when the torque converter unlocks? Maybe I labelled it wrong, rather than "surge" I should've called it a bit of a "shift shock". It isn't a big deal, but it's kind of annoying leaves me wondering about wear and tear on the CVT, to the point where i avoid this by accelerating and braking a little harder which eliminates the effect. Its the gentle acceleration and gentle coasting into stops that produces this effect. Anyone else?

[ahhbeebee]

Kerrton, I guess I finally know what you are talking about

I've noticed this from the beginning also and always thought it was because the computer forced transmission into a low gear when accelerating from a dead stop (I don't think I've noticed it upon slowing down though).

Regarding whether it puts undo or excessive strain on the transmission I don't know, but I know in some older automatics the 'shift shock' is more dramatic and I never noticed any specific wear patterns in the cars which had a lot of this.

Have we established, or are we certain its due to the torque converter locking/unlocking? or could it actually be an 'artificial' low gear the computer uses before letting the CVT start varying?

[Topper1]

I feel a vibration on steering wheel when first starting until RPM reaches about 1200. Is this what you are talking about??

[RO-G]

I feel a vibration on steering wheel when first starting until RPM reaches about 1200. Is this what you are talking about??

no it's not the cvt surge.

[RO-G]

i also experience the cvt surge during stop and go driving on low speeds. i usually shift between "light" and "heavy" foot on the gas pedal during such condition to prevent other cars from sneaking in front of me.

i remember i used to have this problem with my infiniti g35s. i think the dealership corrected the problem by re-programming the ECM which controls the transmission.

does anyone know if our rogues have ECMs as well?

[philipa_240sx]

Does anyone know if our rogues have ECMs as well?

Yes, it does.

[philipa_240sx]

Have we established, or are we certain its due to the torque converter locking/unlocking? or could it actually be an 'artificial' low gear the computer uses before letting the CVT start varying?

The torque converter in the CVT locks anywhere from 11 to 56mph (18-90km/h) depending on engine load. With light throttle application, it should lock up closer to 11mph.

Perhaps this sheds some light on what you are experiencing?