Engine lugging with CVT

[chiphead]

I realize this has been discussed before to some extent here on the NICOclub forums but does anyone have anything additional to add. The Rogue forum seems to have a bit of chatter about this. My 2.5 CVT shifts very early into 6th and at speeds below 35 mph or so and it runs at @ 1250 RPM. If I was driving a stick I'd put it in a lower gear to avoid lugging the engine. I know I can shift manually but does anyone have any insights if Nissan plans to address this or is anyone else experiencing this? Thanks.

[Ferguson]

My 2.5 CVT shifts very early into 6th

What do you mean by 'shifts into 6th'? The CVT transmission NEVER shifts! It keeps the engine at the lowest possible speed for the conditions. If you try to accelerate, the RPM will jump up accordingly. If you back out of the throttle, the revs drop quickly to an appropriate level. You are never 'lugging' the engine - it is quite happy at those lower RPMs when you are just cruising along.

Personally, I am not a fan of the engine droning at low RPM regardless of my road speed - one reason I always drive in manual mode, and use appropriate 'gears' at low speeds. Yes, it wastes some fuel, but it just 'feels' better.

[chiphead]

What do you mean by 'shifts into 6th'? The CVT transmission NEVER shifts! It keeps the engine at the lowest possible speed for the conditions. If you try to accelerate, the RPM will jump up accordingly. If you back out of the throttle, the revs drop quickly to an appropriate level. You are never 'lugging' the engine - it is quite happy at those lower RPMs when you are just cruising along.

Personally, I am not a fan of the engine droning at low RPM regardless of my road speed - one reason I always drive in manual mode, and use appropriate 'gears' at low speeds. Yes, it wastes some fuel, but it just 'feels' better.

If you drop from auto to Xtronic while the engine is "lugging" it will show it is in 6th gear. Using the Xtronic to go from 6th to 5th as displayed on the dash readout eliminates the lugging.I also am not a fan of the engine droning at low RPM.Thanks for the response.

[marlin29311]

If you drop from auto to Xtronic while the engine is "lugging" it will show it is in 6th gear. Using the Xtronic to go from 6th to 5th as displayed on the dash readout eliminates the lugging.I also am not a fan of the engine droning at low RPM.Thanks for the response.

The car decideds which "gear" to put the car in based upon your speed...it's not going to put you in 6th if you're going 30...

The engine sound is just how the 2.5 sounds...can't do anything about that except get a 3.5

The CVT is meant to be an efficient transmission - not a sports car - the car is trying to save as much fuel as possible. The best way to get rid of this is to reset your ECU and have the car re-learn you habits, so basically just kill it all the time and it won't do it.

[Ferguson]

Or... just drive it in manual mode all the time!

[chiphead]

The car decideds which "gear" to put the car in based upon your speed...it's not going to put you in 6th if you're going 30...

The engine sound is just how the 2.5 sounds...can't do anything about that except get a 3.5

The CVT is meant to be an efficient transmission - not a sports car - the car is trying to save as much fuel as possible. The best way to get rid of this is to reset your ECU and have the car re-learn you habits, so basically just kill it all the time and it won't do it.

Can you clarify this marlin? Are you saying if the engine lugs in "6th" just keep knocking it back into 5th and eventually the ECU will "learn" to not drop it into 6th at low speed/low RPMs? Or does the ECU actually have to be physically reset then the above downshifting needs to be performed multiple times after the reset to teach the car? Thanks.

[marlin29311]

Or... just drive it in manual mode all the time!

Lol true!

Can you clarify this marlin? Are you saying if the engine lugs in "6th" just keep knocking it back into 5th and eventually the ECU will "learn" to not drop it into 6th at low speed/low RPMs? Or does the ECU actually have to be physically reset then the above downshifting needs to be performed multiple times after the reset to teach the car? Thanks.

It's odd to me that the car automatically puts you in 6th...even going like 55 my car only goes to 5th...

I think a ECU reset would be a good idea to try for you, as this way you can re-teach the system how you want it to drive.

[Mr. Music]

chiphead, I know what you're talking about. Nissan considers it normal. I went through hell and high water to get it explained... My whole story is here; and here are the cliffs notes on this transmission issue:

...at about 35 mph, the transmission solenoids are almost at the point of sending a shift command. The CVT's gearing is split in banks, first to third gear and fourth to sixth gear. Under normal driving conditions, the transmission wants to shift from its equivalent of third gear to fourth gear at around 35mph, but it basically doesn't know whether to shift or not; resulting in the car jerking back and forth as the pulleys fluctuate. Nissan considers this to pose no reliability, longevity or safety issues.

[chiphead]

[QUOTE=marlin29311]

The car decideds which "gear" to put the car in based upon your speed...it's not going to put you in 6th if you're going 30...QUOTE]I'm not trying to be a wise guy but it deos go into "6th" on a regular basis substantially below 30 mph.

[Mr. Music]

Remember, marlin's car is a 3.5, so his might not got to sixth while our 2.5's do.

[chiphead]

chiphead, I know what you're talking about. Nissan considers it normal. I went through hell and high water to get it explained... My whole story is here; and here are the cliffs notes on this transmission issue:

Thanks for the response music. I don't have any jerking or gear hunting it just drops into top gear very early and lugs the motor at 1250 RPM.Thanks for the link to your previous post.I can and most likley will live with this because I truely love the car but I would love to hear more input such as yours and the results they were able to obtain from the dealer. In my case, it would almost seem as if Nissan should re-program the shift points to prevent it from dropping into 6th below 25 or 30 mph.

[Mr. Music]

In my case, it would almost seem as if Nissan should re-program the shift points to prevent it from dropping into 6th below 25 or 30 mph.

That can be done - it was an option for me before I finally discovered what the "problem" truly is. Nissan has to get an engineer out to your dealership to do it though, so don't head to the service department and expect it fixed right then and there.

[chiphead]

[

The car decideds which "gear" to put the car in based upon your speed...it's not going to put you in 6th if you're going 30... QUOTE] I'm not trying to be a wise guy but it does go into "6th" on a regular basis substantially below 30 mph.

I need to clarify this. I was sucking wind on part of my observations. I played with this on the way to work this morning. The issue isn't that it goes into 6th to early. It goes into the next highest gear relative to vehicle speed to early. It can be any gear. It seems the "shift" points are @ 500 RPM to early causing the transmission to select the next highest gear to keep the RPMs @ 1250 under light throttle pressure. At 1250, the engine appears to lug and a slight "booming" is heard. So my question is has anyone been able to get Nissan to rectify this so the "shift" points are 500-750 RPM higher? Appreciate everyone's input.