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slight shaking when idling

41K views 20 replies 14 participants last post by  Mongo53 
#1 ·
hi all! haven't been on in a while, no issues with the Jeep until last week.
out of nowhere it started doing this weird thing when I'm stopped at a light or in traffic idling. (it doesn't do it every time, but almost every time depending on how long im stopped for) I feel a shake or hesitation or shudder similar to the feeling you get when it's going to stall, only not to that extreme. I'm not worried it's going to stall, but it's definitley not right. the engine doesn't make any noises when it does this and the engine otherwise is running totally fine, doesn't sound different. No check engine light and the gauges aren't fluctuating or anything when it does this.

worried it may have something to do withe cylinder misfires....:(
it's a V6
taking it to jeep this week
 
#10 ·
My '11 had gotten a tad bit of a rough idle. I had to make about a 1000 mile round trip week before last so on the return trip I filled up with 89 octane NO Ethanol. The idle seems to have cleared up.

Just for info, I was getting 22 mpg running 87 octane 10% Ethanol on the tank going and I got 24 mpg running the 89 octane NO Ethanol on the return trip. Speeds around 75 both ways all interstate.
 
#13 ·
Key to listen for is a buzzing or humming from under the car once you have turned it off.


For all of your ideling problems just remember the word TIPM. It starts with the ideal and ends with you not being able to crank the car. It is actually your fuel pump shorting out. There's a lot of threats on that and jeep is issued a recall for that computer system. Jeep will not touch your car when he comes to recall until it just stops running altogether. In my case my wife was driving and it died on the interstate at 70 miles an hour. That was before the recall and I got rid of the car due to the $1200 price tag and no guarantee of it being fixed due to them not upgrading the system even though they know it has an issue.
 
#15 ·
Me too. Mechanic I trust suggested swapping aftermarket non-oiled intake back to the stock airbox with new filter and then he'd do a TB cleaning. Said the spark plugs are totally fine and wouldn't do anything, I guess he was right based on what I just read here. But seems like the TB cleaning didn't help folks here either.


Thinking some more now on my own, I wonder if its just age and the engine mounts starting to wear out. I hope it's not what the first poster on the page said about the TIPM and fuel pump short, cuz I do I hear a buzzing/humming sound once in a while from the car when it's off. It's always done that though...
 
#17 ·
Thinking some more now on my own, I wonder if its just age and the engine mounts starting to wear out.
I’ll almost guarantee it’s the engine support mounts. Mine went “south” at about 80k miles on my ‘11 Laredo X. Started noticing shaking and studdering especially at idle almost like the engine was about to die... but RPM’s were always steady and smooth. I finally realized it was the engine mounts when the driver side mount started leaking hydraulic fluid on the driveway several weeks after the symptoms started.

It’s a $700 fix at the dealer. I ended up buying two Mopar OEM mounts on Ebay for $110 shipped and paid a Craigslist mechanic $90 to install them. The thing has run smooth as silk since.
 
#16 ·
I had the same issue for my 16' limited 3.6L. It only has 22000mi. Come on FCA,,,,,

It happens at the traffic light, mostly at first cold start first traffic light after overnight parking.

Try to duplicate your symptom in the morning when your car is cold see if you get the same issue. Mine happens around 30' second after a full stop.

I am also doing 89/91 gas experiment as I hear light knocking sound with 87. I have been running 91 for over the weekend and looks like the knocking sound is gone.

:(
 
#20 ·
hi all! haven't been on in a while, no issues with the Jeep until last week.
out of nowhere it started doing this weird thing when I'm stopped at a light or in traffic idling. (it doesn't do it every time, but almost every time depending on how long im stopped for) I feel a shake or hesitation or shudder similar to the feeling you get when it's going to stall, only not to that extreme. I'm not worried it's going to stall, but it's definitley not right. the engine doesn't make any noises when it does this and the engine otherwise is running totally fine, doesn't sound different. No check engine light and the gauges aren't fluctuating or anything when it does this.

worried it may have something to do withe cylinder misfires....:(
it's a V6
taking it to jeep this week
Did you get it resolved? I have same issue, in drive idle is about 600rpm, go to neutral or park and idle rpm goes up and it goes away.
 
#21 ·
There are lots of posts about the WK2's oil filled hydraulic motor mounts going bad as early as 60k miles, some even earlier than that.....
I replace my motor mounts myself, I did a how to....

In that how to I described an easy test you can do to see if your motor mounts are bad.....

Since the HEMI has a plastic oil pan, you can not lift the engine with a floor jack to replace the motor mounts. The Dealer has a special tool and expensive engine lift jack that lift the engine from the top, that requires removing the intake manifold. Yes, no kidding, because of their design decisions they made replacing the motor mounts 10 times more complicated and thus much more expensive in labor; but hey at least they selected a motor mount that need to be replaced 3 times more often than most motor mounts.....

I figured out a way to lift the HEMI with a Floor Jack, but its risky and you need to be very careful.....

The V6 has a two part oil pan, upper half metal and lower half plastic, if there is enough flat area on the metal pan, you might be able to lift it with a floor jack and avoid all the trouble I went through with the HEMI.... ....I have yet to hear from anyone that has tried it on the V6....

Finally, the area the motor mounts is in is pretty tight and difficult to get the room to work in, then they also put heat shields over the mounts, with little bolts that are hard to get too. So yea, besides the difficulties and time in lifting the motor, you still have to double/triple the time of unbolting/bolting out/in the mounts because the area to work in is so tight.....
 
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