engine revving on its own

Hi everyone. I need to make sure I'm not going insane!!! Help! I have a 2015 6 speed MT TRD off road tacoma with 5400 miles on it (it's brand new why is this happening!!!)

I took my truck in for a new cv axel. Got it back and now it does this:
At idle it randomly revs anywhere from 900 to 1100 sometimes 1200 (well past after warming up, it goes all over the place).

While driving, if I push the clutch in the rpm hangs for a second (as it always had) and the drops to its idle rpm, then soars up on its own to 1500 to 2000 rpm, all on its own. Foot off the gas, out of gear, clutch to the floor. It will go back and forth to all kind of random rpm holding for a few seconds and changing to a different rpm. Just like the when it idles now just more exaggerated (it used to hold idle at like 900-1000 once warmed up, none of this speraticaly changing stuff).
Toyota (local dealership) is saying this is completely normal. They said they drove a brand new taco and it does the same thing. Did I never notice it before? Or wtf!!!!

Thanks in advance. I'm freaking out over this. Im 25 yrs old and this is my largest purchase ever and I'm 99% sure they are trying to screw me. None of my old MT ever did this.

 

Sounds like a vacuum leak. It's not normal, I've had a 2009 6 speed manual and never had your issue. Rev hang is normal though.

 

Okay, thanks for the feedback.

 

^^^^
What he said. I also have a 2015 6 spd (approx 8500 mi.) and haven't noticed any rpm changes, just the rev hang between shifts.

 

That dealership employee is lying to you. He is trying to weasle out of spending money to fix your problem. Ask to see the service manager or go to another dealer.

 

Thanks for the feedback. I'm in the process of that now. I had to contact Toyota in order to get this local service manager to even talk to me. I'm jumping through so many hoops. So frustrating. They are putting more effort in avoiding the problem than just fixing it.

 

I ran the Taco into town today: 750 rpm, in neutral, rock solid, no variations. (No A/C or accessories on either...)