Thanks for taking the time to read my post. I tried to cover everything—but let me know if I missed something important.
I have a 2006 Rubicon TJ 4.0 i6 w/automatic transmission (120k-ish miles) with a rough idle.
More info:
• I believe it only happens when it's up to normal running temp (needle right in the middle)
• Typically happens at stoplights or when starting it up again when it was just recently run
• Sometimes it's nonexistent/barely noticeable, sometimes it feels like it's going to stall out, which is a bit worrying when I'm far from home
• When it does feel like it's really going to stall, it usually stops after 10-30 seconds of idling
• Seems worse when I've been doing interstate driving for 30+ minutes and then stop at a light
• Seems to stop being rough when I give it gas/start going again OR rev it up a bit in neutral
• Starts up really rough if it's hot, but only sometimes
• No check engine light, codes, or other related issues from what I can tell
• Took it to the shop several times, and they didn't seem to have any ideas or suggestions
• I think idle rpms may be a little bit lower when I have the issue compared to when I don't have the issue (I'll have to look at them next time I'm out to double-check this and be more specific). The needle doesn't seem to be erratic though.
I'm a bit tired of taking it to the shop because they seem pretty dismissive about it, and I'm not sure they are really looking into it—even when I bring it in hot/as it's running rough.
What I've tried:
• Replaced upstream O2 sensors with the right ntk parts, as recommended here (also one downstream sensor earlier in the year when I replaced the CC)
• Replaced TPS (Mopar)
• Replaced IAC (Mopar)
• Cleaned throttle body and ran throttle body cleaner through the intake while running as Jerry recommended
• Replaced spark plugs (with ones recommended on here)
• Tripple-checked spark plug gap (with the recommended gap on inside hood sticker) AND with multiple gap tools, just to make sure
• Vacuum lines seem fine/not cracked, but I had a mechanic check them anyways—everything checked out
EDIT:
Also, I bought a new battery, and the alternator doesn't seem to have any problems
I've let it run for a week or so after each replacement, and there hasn't seemed to be any change. The problem has been happening for 6+ months.
Do you have any ideas as to what might be causing this rough idle?
This user seems to have fixed their rough idle with a new camshaft position sensor.
Is this a common issue—and is it worth trying? If so, it seems that the part (is this the right one?) is discontinued. I'm guessing I can only use a Mopar part—do you know where I should look to find one, OR is there a specific aftermarket part that would work without causing issues/codes?
Another question: I came across Chris' post about OPDA issues in some TJs.
Would this be related to the issue I'm having? I don't seem to have the squealing sound that is associated with this problem, but I figured I'd ask anyway.
Thanks again for taking the time to read this!
I have a 2006 Rubicon TJ 4.0 i6 w/automatic transmission (120k-ish miles) with a rough idle.
More info:
• I believe it only happens when it's up to normal running temp (needle right in the middle)
• Typically happens at stoplights or when starting it up again when it was just recently run
• Sometimes it's nonexistent/barely noticeable, sometimes it feels like it's going to stall out, which is a bit worrying when I'm far from home
• When it does feel like it's really going to stall, it usually stops after 10-30 seconds of idling
• Seems worse when I've been doing interstate driving for 30+ minutes and then stop at a light
• Seems to stop being rough when I give it gas/start going again OR rev it up a bit in neutral
• Starts up really rough if it's hot, but only sometimes
• No check engine light, codes, or other related issues from what I can tell
• Took it to the shop several times, and they didn't seem to have any ideas or suggestions
• I think idle rpms may be a little bit lower when I have the issue compared to when I don't have the issue (I'll have to look at them next time I'm out to double-check this and be more specific). The needle doesn't seem to be erratic though.
I'm a bit tired of taking it to the shop because they seem pretty dismissive about it, and I'm not sure they are really looking into it—even when I bring it in hot/as it's running rough.
What I've tried:
• Replaced upstream O2 sensors with the right ntk parts, as recommended here (also one downstream sensor earlier in the year when I replaced the CC)
• Replaced TPS (Mopar)
• Replaced IAC (Mopar)
• Cleaned throttle body and ran throttle body cleaner through the intake while running as Jerry recommended
• Replaced spark plugs (with ones recommended on here)
• Tripple-checked spark plug gap (with the recommended gap on inside hood sticker) AND with multiple gap tools, just to make sure
• Vacuum lines seem fine/not cracked, but I had a mechanic check them anyways—everything checked out
EDIT:
Also, I bought a new battery, and the alternator doesn't seem to have any problems
I've let it run for a week or so after each replacement, and there hasn't seemed to be any change. The problem has been happening for 6+ months.
Do you have any ideas as to what might be causing this rough idle?
This user seems to have fixed their rough idle with a new camshaft position sensor.
Is this a common issue—and is it worth trying? If so, it seems that the part (is this the right one?) is discontinued. I'm guessing I can only use a Mopar part—do you know where I should look to find one, OR is there a specific aftermarket part that would work without causing issues/codes?
Another question: I came across Chris' post about OPDA issues in some TJs.
Would this be related to the issue I'm having? I don't seem to have the squealing sound that is associated with this problem, but I figured I'd ask anyway.
Thanks again for taking the time to read this!
