after warming up my car from a cold start, driving at around 20mph and 2k rpm, the rpm bounces from around 1.9k to 2.1k and the car is making this slight rocking motion back and forth?

anyone know why??

im taking it to the dealer tomorrow but i just want something to back up just incase they say "its normal".

recently i've had the valve stem replaced in the front passenger tire.. and a patched tire in the rear driver side tire.. also an alignement so i have no clue whats goin on..

please help!

 

Are you meaning that while driving it won't stay at exactly 2K rpm? I'm not sure I'm understanding your question.

 

if you're driving at 20mph, do you honestly think the rpm will just stay at the same RPM the whole time? try checking the RPM's at a dead stop when there aren't any variables such as incline/decline. it should be normal

 

Are you using the cruise control? If so, I believe there is a TSB on that one.

 

well when driving off i accelerate slowly.. and when it gets to around 20 mph and 2k rpm.. it starts to bounce.. therefore causing the rocking motion i guess..i didnt try to accelerate while it is bouncing.. but this should not be a normal thing.. this started to happen recently..

 

I doubt seriously that they are going to find anything wrong but even if they do, I'm betting it will be something very minor.

Am I to understand that the car hasn't been above 20mph since it did this the first time?

 

My car is having the exact same problen happens at around 20 MPH and under very slow acceleration. Step on the accelerator and the problem desapears. Seems to be the tranny trying to figure out what to do and not an engine problem. Please let me know what does the dealer tell you, I have an appointment set up for next week.

And yes I'm sure the dealer won't find anything wrong as the problem is very difficult to reproduce, it doesn't happen everytime.

 

Hey P have you tried cleaning your throttle body and MAF sensor?

 

If you are in an automatic that would make sense because the tranny is set to shift right around there. The OP said it was the first time it had done this and it could be because with the warmer weather, the AC is running where it may not have been before. I will say that most likely the dealership is going to say everything is fine and send you on your way home.

 

obviously the rpm doesn't stay the same.. if the rpm jumps up and down enough to feel it pull back and forth then obviously theres a problem..

no i haven't.. you think thats the problem?? i have no idea how to clean it..

well at that time it didnt shift until i went around 3k rpm.. and it jumps up and down about like 5-6 times.. my gf felt it and she was like wtf was that..

it stops jumping after i go higher speed and for the rest of the day.. it seems like its only from a cold start.. so i think it'll be hard for the dealer to check it out..

 

Just read the 045 TSB mentioned above and seems to describes the problem I'm having, my only question is what does the term cold soak means.
Does it mean that the car cooled off after been off for a while or does it mean that it was seating in very cold temperatures.

BTW My car is a S, Prem. Non Nav.

Edit. Never mind TSB specifies that the problem is related to engine temp and not ambient temp.

 

Excuse me, you were asked a question NICELY to clarify the situation you were having. Responding with a smartass answer is not the way to get further help in the future.

 

My point was that it may have been in that tiny area where it doesn't know if it should shift or not. I recall my '04 doing that a few times when it was cold but it was pretty much only the first time you really started off. You may need to just plan on leaving it at the dealership overnight so that they can check it first thing in the morning while it's cold.

 

ok i edited, sorry for the attitude. the way i read his post it seemed like he didnt understand the problem and tried to be a smart guy by saying something obvious.

no i haven't but i just looked it up and it does seem to apply... ima bring it to the dealer and if they say nothing is wrong them i'll flash them the tsb.

thanks everyone for your help. highly appreciated.

 

Mine was fixed here at infiniti of PR, Kennedy. Ask for Yamil of service and tell him that you want the same reflash of my car. After that my car is Ok.