The issue is that maybe once every 10 or so stoplights the rpm will drop down from idle, around 700 rpm, and bounce between the 1st and 2nd mark on the techometer. I can get it to do this also by revving the car a bit and removing all throttle input while in park.

As it bounces, I can hear the engine struggle. Sometimes I thought it was going to stall.

This has happened with the AC on and off.
This car is STOCK, with nearly 55k miles.

The only thing I can think of that it would do before I had this RPM bounce is after being warmed up, the car idling at around 700 rpm. Every once in a while the needle will very slightly drop a mm and i can feel a slight impulse vibration as I hear the car and or exhaust makes a "putt" noise. Not loud but basically the same volume of the noises it's already making on idle.

Else the car seems to run just fine. It has power, accelerates well, etc.

Other issues online sounded close to it but not quite. Hard to tell with just word descriptions, so for this post I added a video.

Any help is greatly appreciated.

 

Sorry to hear your having issues. Did you buy it used? Did you buy it at a dealership?

 

No, I've had it for over 4 years, bought it new at the dealership.

I don't race, it hasn't been in some huge wreck, and I keep it on a regular maintenance schedule.

Someone else suggested the air control valve or O2 sensor.

 

There is no cel on right now is there? And you should take it in the the dealer and have them fix it if its still under warranty.

 

Check all your vacuum lines. Also check to make sure your factory air box is good and tight (i.e. filter etc)

 

+1 on dealer
It might be the timing chain starting to stretch causing your idle to be off, but not stretched enough to throw a code.

 

+1 on the chain

The first couple of years had a timing chain problem.

 

+1 to the Dealer.

I am at 47K currrently, I had the exact same thing happen, but it happened when I finished my drive home and pulled into the garage. I thought nothing of it, until my car threw the Timing chain tirangle of doom, but no CEL.
I had my timing chain replaced under warranty, at 44K.
It hasn't done this since. They also flashed the comp back to stock & relearned the valve timing. I paid for an oil selonid valve that works the vvt, that wasn't under warranty, $220. ( I think it was the exhaust side)

Chain stretch is nothing to mess with. PM me if you want more info.

Not worth stressing over, Good Luck.

 

If this continues to happen, and idle wobbles almost to the point where the car stalls, it could also be an issue with the throttle body. Unfortunately it is inseparable from the throttle position sensor, so it is a big bill to replace.

It will throw a code of P0122 or something similar.

Unfortunately the throttle body/tps is not covered under the powertrain warranty.

 

Yeah, I checked the vacuum lines and air filter. They looked fine.

I just made an appointment with the dealership, but the earliest will be Monday.

Figured I'll save some time by having them do the 60k maintenance with it, so I'm making a list of other things I might want them to check in the mean time.


I sure hope this isn't the case then

 

I had the same issue. Cel came on a day or two later. Dealer replaced the maf under warrenty and no futher issues.

 

Forgot to say no CEL as of yet.

Had to push my appointment to Tuesday.

The service department was shared between to separate dealerships, Mitsubishi and KIA. The KIA dealership handled most of the things upfront with a Mitsubishi tech in back, and the KIA dealership moved away this Saturday. When I arrived, the Mitsubishi was setting up their computers and such and said it was better if I rescheduled so I did.

A little annoyed but it was the KIA people that set up the appointment so...

Hopefully they are all set up tomorrow and they don't feel like they have to rush to get my car back to me.

 

So I just got my car back and they dealership said it was the throttle body.

The invoice notes states no codes came from the scan, cleaned build up in the throttle body, and that they could not duplicate the issue after that.

I got home, parked it in the garage, and tried to get it to surge again. Could not. The needle is more stable as well, not so twitchy.


Thanks everyone for your suggestions!!!

 

That's awesome news! Did they charge you anything or was it covered by the warranty?

 

I guess our cars could benefit from an oil catch can.
were you using stock air filter or oil type? (K&N)