Hi, so when I am driving and I go to slow down my RPM’s go up anywhere from 500 to 1000 RPM’s then go back down. It does this a few times til I usually either come to a complete stop or I speed back up. It has only been doing this for a few days. My Nissan Rogue has 76,000 miles on it currently.
Have you ever changed the transmission fluid? You should have done that 16,000 miles ago. That might be the issue.
I agree with Mustangman as for it being a transmission issue. However, I venture a guess that it is the transmission downshifting as you slow down. As the tranny goes into a lower gear, the engines RPM goes up momentarily to compensate for the lower gear. I’m not saying it’s normal, but just a symptom of other issues with the tranny. So, did you change the fluid?
Try slowing down using a fixed gear (rather than D), then slowing down in neutral. What happens to the engine rpm in those cases? Also try this: At idle, stopped, engine warm, everything unnecessary for this experiment turned off, step on the gas pedal to increase rpm to 1500.
Maintain 1500 rpm for 10 seconds. Now remove your foot from the gas pedal. What happens?
I suspect this has gone unnoticed until now. The computer will adjust the CVT to provide a small amount of engine braking while slowing. The elevated engine speed can produce a cleaner emission output.