silvurback

i apologize if this is a repost, but i searched and didn't find anything similar to this problem.

ok, so last wednesday i bought a new 09 JK and ever since i got it it's been idling pretty rough. i didn't notice it on the way home because i was doing 80 mph almost the whole way. today the check engine light came on so i took it to the dealership and had them check it out. they said that the 6th cylinder was misfiring. they took it in and fixed it and said that should take care of the rough idle, but it hasn't. it's still doing it. does anybody know what this could be? a buddy of mine that's the service manager gave me a can of fuel cleaner that they use. he said it should take care of the problem. will this help? any help will be greatly appreciated!

greenjeep

I've read on here before many have had rough idles. i'm at 6,800 miles and have had rough idles almost constantly...

Just-Say-JK

I picked up my new 09 last week. I have the same rough idle. It's booked in this Friday to try and resolve it. I'll post up if they find anything.

silvurback

thanks for the response guys. maybe it's a "Jeep thing" lol. definitely post up if they find anything! thanks!

johnnyd

Most fuel cleaning solutions are used to clean the injectors, it would be hard to believe an injector is dirty. There is no reason this new V6 motor should run rough at idle. Something is wrong. I would be inclined as a technician to check the injectors.

silvurback

so would it be wrong to run the cleaner through to see if it helps before i consider taking it back in?

thanks for the reply

johnnyd

Wouldn't hurt it at all, just pisses me off to think maybe the dealer is trying to save the mothership money by not properly diagnosing injector operation. I wonder what code was thrown by the computer.

Edit: Run it down the road again at 80 and see if the Idiot light comes on again. If it does, a component - ie an injector, is malfunctioning.

silvurback

i just got out my receipt and the code was P0306. it also says they cleared the code and retested. "ok at present"

does that mean they just reset the check engine light and handed me a receipt?

JKlad

Yeah, P0306 is a "cylinder 6 misfire". Apart from injector or computer problems, could be your plug/coil connections that are loose/faulty.

Was doing some offroading on bumpy & muddy terrain in the wet & had a miss on idle the next day on start-up. Threw up a cylinder 2 misfire code on mine, so pullled the plug & coil cables which were wet & muddy & a little loose, dried them out (wife's hairdryer), plugged it back in & it's been fine ever since.

cmpmacchia

A slight rough idle is normal on these v6 engines. Can you describe in detail the condition. Does it happen only at a dead idle especialy durring warm up? I've had this condition since new and it quite common especially when compared to a refined engine. Not that these engines are manufactured badly they are just less refined.