So I have been dealing with this for month's and have researched it immensely and cannot really find a solution. Been to the dealer and they say its working normally. My mechanic can't figure it out.

Half the time I am in drive stopped at a stoplight or stop sign, my rpms will drop to around 500ish and the car will idle rough. Nothing crazy like the steering wheel shaking but it vibrates in the seat pretty bad and is honestly so annoying. If I turn the ac on while this is,happening, the rpms go up to 600 and stay there and the vibrations go away.

I understand why its vibrating, it is because the rpms are low. But why is my cars rpms dropping like that? Unless I put more load on the engine, the rpms do not jump back to 600. Sometimes everything is fine, the car will idle at 600 -650ish. I have cleaned throttle bodies, had the dealer preform a throttle relearn and check the bodies as well. No codes either. Change my oil every 4k with synthetic. Also just changed my diff and transfer chase fluid. Have no idea what it could really be. The dealer says it is fime and just needed a proper idle relearn but that did not really do anything. Some days it is fine, others it so annoying. 127k. Does the g37 have an iacv? Maybe it could be thatthat.

 

How are your spark plugs? and have you done an A/F Reset? https://www.infinitihelp.com/diy/gse...f_learning.php

 

I have not done that reset, haven't even heard of it lol. Spark is were replaced 20k miles ago and from what I know, I have no oil problems so I dont think it could be the plugs, but its worth a check.

 

Wonder if your crank pulley is going bad

 

ahhh I hope not, that would not be good considering how long I have been driving like this. Back to the dealer tomorrow but I really don't even know what to do at this point since they keep telling me it is normal.

 

Did this ever get solved?