[fsmith]

My 2012 6sp Versa (recently purchased) delays dropping rpms when foot is taken off pedal (delay is about a second or so). This happens at all times, but is mostly problematic when upshifting quickly (e.g., when going through the low gears quickly to merge into fast moving traffic, shifting becomes a bit jerky). In my other manual shifts (have only had manuals - for over 30 years), engine speed drops off as soon as foot is taken off the pedal, but my Versa does not (in fact, it seems to increase rpm ever so slightly before dropping off a second or so later). Another thing about this problem, is that it only happens when the engine is warm. When the engine is cold, it seems to behave as I expect. I took the car to the dealer, and was told that this is normal behaviour intended to prevent back-firing (from Back-fire - Wikipedia "In some high-performance vehicles, when a driver shifts up and lets off the accelerator, the engine has a moment of running rich. This causes an incomplete burn which causes the fumes to explode in the exhaust system along with an audible pop or bang sound"), and that Nissan has not issued any technical bulletins regarding this, and that I should inform Nissan central, if I feel that this is a problem. Has anyone experience something similar?

Thanks.

 

[robj80]

Nope as soon as I remove my foot from the gas pedal rpms slowly start to drop. Most likely this is some sort of electrical issue since our cars use throttle by wire systems. If this were an older car with a cable I would say your cable is binding or your throttle plate is sticky.

Go the the dealer and have the service guy drive with you in another 2012 6spd. That way you can show him what you want your car to behave like.

There are several other things that might cause an issue like this but since this is a new car it's best to hound the dealer about it and let them figure it out.

 

[fsmith]

Thanks for the input, robj80. I've been super busy and have not been able to get back to this for some time.

By coincidence, about a month later, I brought my Mazda 5 (5 spd manual) to a garage for some suspension related work. It was a new shop (for me), and I found out that Nissan vehicles are there specialty. So I asked the guy about my Versa, and as soon as I started to explain the problem, he recognized it. According to him, all recent model manual shifts do this (regardless of manufacturer - his Honda does it), and it's to do with emission control. Apparently, when engine speed drops off suddenly, some unspent fuel vapour makes it way into the exhaust (values open at the same time, I believe he said). And (some?) governments are asking (forcing?) manufacturers to keep the revs up for a short period when the clutch is depressed (it's all computer controlled), so that this doesn't happen. The guy told me that they (or I) could tune this all out, if I wanted to, so that it would behave as I was used to. Since my vehicle is under warranty, I've decided not to do so, for now. Instead, I've adjusted my behaviour to make the shifting smoother. Now, I didn't think to ask whether this was just for vehicles to be sold in Canada (where I live), or other jurisdictions as well.

 

[08versailles]

interesting, where ya from? welcome

 

[jswilson1987]

it makes shifting harder not to mention the crappy torsion mounts and a clutch with almost no feel

 

[Tubtub]

The Versa doesnt drop rpms fast when the throttle is released because its got a heavy rotating mass and drive by wire. The jerking when shifting is from the soft rubber motor mounts. This car is no race car

 

[jswilson1987]

^^^^god i hate those motor mounts whos tried the torque mount from racingline? I know the mounts are soft cuz i can rock the engine by hand:ack2:

 

[fsmith]

interesting, where ya from? welcome

I'm in King Township - thanks.