2013 JK Auto - Jumpy RPMs

Anything concerning your jeep... Repairs, parts, etc
Post Reply
Joleat
Newb
Posts: 38
Joined: Fri Mar 25, 2016 8:25 pm
Vehicle: 2013 JK
Location: Charleston, WV

2013 JK Auto - Jumpy RPMs

Post by Joleat » Tue Oct 18, 2016 9:39 pm

For the last 3-4 months, I've noticed a jumpy RPM issue that is becoming more prominent. It occurs with and without cruise and seems to be most apparent at 60-70mph. When it occurs, it may last for 5-6 seconds and it sounds like it is modulating 50-100 RPMs very quickly up and down. With that said, it doesn't do it all the time, but I do notice it more when the throttle is applied to keep the speed up and not so much when the Jeep is coasting.

Also, the RPMs sometimes drop (well under 500) abruptly when I'm switching from drive to reverse and back to drive when turning around. I know gear change-related RPM variation is normal, but when they drop in these scenarios, it almost feels like the Jeep is going to stall.

The JK has 37k miles and there are no CELs. Does anyone have any suggestions as to where I should start troubleshooting?

Thanks!
Roads? Where we're going, we don't need roads...

User avatar
wharthog69
WVJC Member
Posts: 1991
Joined: Mon Oct 12, 2009 3:08 pm
Vehicle: 2008 JK

Re: 2013 JK Auto - Jumpy RPMs

Post by wharthog69 » Tue Oct 18, 2016 9:59 pm

Probably obvious, but check the battery and alternator terminals. My JK battery lost a cell at 3 years, the replacement lasted about 4.

Joleat
Newb
Posts: 38
Joined: Fri Mar 25, 2016 8:25 pm
Vehicle: 2013 JK
Location: Charleston, WV

Re: 2013 JK Auto - Jumpy RPMs

Post by Joleat » Tue Oct 18, 2016 10:10 pm

I'll do that. I've given pretty much everything that is easily accessible within the engine bay a quick once over. Nothing appears to be suspect on the surface. I was thinking it might be related to a sensor, but again, no CEL.
Roads? Where we're going, we don't need roads...

Joleat
Newb
Posts: 38
Joined: Fri Mar 25, 2016 8:25 pm
Vehicle: 2013 JK
Location: Charleston, WV

Re: 2013 JK Auto - Jumpy RPMs

Post by Joleat » Thu Oct 20, 2016 9:14 pm

I checked all connections and didn't find anything.
Roads? Where we're going, we don't need roads...

User avatar
J-rod
Moderator
Posts: 7653
Joined: Tue Jan 29, 2008 1:24 pm
Vehicle: 2008 JK, 2005 KJ
Location: Farmington WV

Re: 2013 JK Auto - Jumpy RPMs

Post by J-rod » Fri Oct 21, 2016 8:28 am

check throttle body connection? check and or clean IAC / IAT?
check/clean throttle body?
Jared:
His: 2008 JK Unlimited Build Thread
Her's: 2005 KJ
Building a capable off road Jeep is easy...building a street legal one that you can drive two hours away to wheel and then drive to work the following morning is the challenge.

Post Reply