Idle issue?

KK_Canuck_Guy · **Posted:** Fri Feb 03, 2012 3:30 pm

Hey all!

So I recently noticed that when sitting at a stop and the engine is idling (Around 600rpm), every now and then it will kinda ...shudder, the rpm's don't drop much...just to about 400 and then go back to 600. When it does happen, the shudder only happens once and then it's back to normal..like nothing happened.

Anyone else experience this? Should I be worried about this?

A little background on the Jeep, it's an 08', auto tranny and i'm sitting at 98k on the engine.

Luny421 · **Posted:** Fri Feb 03, 2012 6:55 pm

i've had a similar problem with my '08, not so much a shudder, but sort of a rough idle, like the entire Jeep shakes when sitting at a stop light...rpm's don't change, and it doesn't happen all the time...i'm curious to see what folks have to say

Jeepin_it_real · **Posted:** Fri Feb 03, 2012 7:56 pm

how many miles you got on your truck? factory spark plugs? I will bet that if you have over 20k on it it's time for plugs or if you dont i'd check out the plugs and see the gapping :2cents:

Luny421 · **Posted:** Fri Feb 03, 2012 8:20 pm

Jeepin_it_real wrote:

how many miles you got on your truck? factory spark plugs? I will bet that if you have over 20k on it it's time for plugs or if you dont i'd check out the plugs and see the gapping :2cents:

I just rolled over 50K a week or two ago. i'll check the gaps this weekend, when i changed my plugs about 8-9 mos ago (so i've put about 8-10k miles on them since), it stopped with the rough idle...good thinking, thanks

KK_Canuck_Guy · **Posted:** Fri Feb 03, 2012 8:23 pm

Jeepin_it_real wrote:

how many miles you got on your truck? factory spark plugs? I will bet that if you have over 20k on it it's time for plugs or if you dont i'd check out the plugs and see the gapping :2cents:

Hmm..as stated mine is about 98K now. Will check the plugs. Thanks!

RenegadeKC · **Posted:** Sat Feb 04, 2012 11:27 am

I've felt this same thing with my 2010. I'll have to check my plugs, as I've got about 23,000 miles on mine.

Diggerfreek · **Posted:** Sat Feb 04, 2012 7:33 pm

Same thing happens on my to. I have 12K on my plugs.

Luny421 · **Posted:** Tue Feb 07, 2012 6:51 pm

well, i pulled all the plugs and all were in the range of .041-.043, so i re-gapped all of them to .040, still have the rough idle...oh well, it seems somewhat common so i won't sweat it...thanks for the info though

Smetna · **Posted:** Wed Feb 08, 2012 7:25 pm

My 2011 with 12k miles does this on occasion. I think it's gotta be normal 3.7L PowerTech operation.

Not to hijack this thread, but, what spark plugs do you guys recommend for long-term engine health?

Or is there a thread about plugs already?

black and blue · **Posted:** Tue Feb 28, 2012 9:11 pm

i changed my plugs about 1,000 miles ago. the idle seemed to improve at first, but now it seems like it may even be worse than before.

the plugs I pulled had expanded beyond the gap spec, i think the worst one being like .050, but i double checked the gaps on all my new plugs, autolite DP.

:ALONE:

hrogi · **Posted:** Wed Feb 29, 2012 12:10 pm

THere are so many plugs.

The safe bet is the factory plugs will give you what you are after...

We all know the aftermarket has many options...
I am not looking to bring up huge flame wars here, but you might want to research a little.

But maybe a few people could comment on their long term results from other 3.7L motors and what they have tried and stick with...

Diggerfreek · **Posted:** Thu Mar 01, 2012 9:51 am

So far I have had autolite plats and autolite double plats in mine. I only have a few hundred miles on the DP's, but I like them better. I can't find the OEM NGK plugs out here with out going to the dealer.

Marlon_JBT · **Posted:** Thu Mar 01, 2012 2:40 pm

I think we all have this problem.

It's so widespread of a problem, that it is normal.

I feel it every once in a while. It recovers very quickly and never stalls.

I don't worry about it. Doesn't matter how many miles are on the plugs, it will... just happen out of nowhere.

WolverineFW · **Posted:** Thu Mar 01, 2012 6:59 pm

You guys have your A/C on when this happens? Or your vent selector on defrost and or floor? Could be the A/C compressor kicking on and off like on the CRD's? Just a thought.

Marlon_JBT · **Posted:** Fri Mar 02, 2012 4:14 am

WolverineFW wrote:

You guys have your A/C on when this happens? Or your vent selector on defrost and or floor? Could be the A/C compressor kicking on and off like on the CRD's? Just a thought.

I used to have a CRD.
A/C doesn't have to be on.
This isn't that, trust me. (I kinda miss that A/C Compressor shake though!)

Luny421 · **Posted:** Fri Mar 09, 2012 5:42 pm

I'm beginning to think it's just the inherent vibration associated with a 90° V6...

Jynxd · **Joined:** Thu Jan 05, 2012 4:57 pm **Posts:** 2

I just had the plugs, wires and one coil pack replaced. My still idles funny.

hrogi · **Posted:** Thu Mar 15, 2012 4:45 pm

Here are exptreme things to change, adjust, and or clean.

1. Index spark plugs to maximize the flame front
2. clean the throttle body every oil change
3. Try differant types of Oil in the engine case
4. Only make right hand turns
5. Loosen and retorque all the bolts you can find
6. let the motor run for 3 minutes before you leave your parking spot
7. clean any sensor that meters the Air coming into your Jeep
8. Get differant motor mounts
9. Change the tranny mounts
10. get softer hoses for the radiator
11. move onto a new Jeep or live with this thing...
12. change the Gap in the spark plugs till it runs better.

Just a few ideas.. most will do nothing, others are just for fun...

smigelskijk · **Posted:** Thu Mar 15, 2012 6:37 pm

Dang I've been doing left hand turns :dizzy:

KKboy · **Joined:** Tue Mar 04, 2008 10:36 pm **Posts:** 26

I have a 2008 Sport North Edition with the 3.7 litre and auto transmission. I've experienced this stumbling idle issue in the last couple of years. I have had my dealer do an injector cleaning twice. It seems to stop for a while, but I noticed it does come back. I'm running Bosch Platinum +4 plugs, installed at 60k, now at 102k. Now I'm wondering if water condensation in the fuel might be causing it. Should try a little gas line antifreeze in the tank.

Idle issue?

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