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Discussion Starter · #1 · (Edited)
Many of us have it and gone nuts looking for it. Some even had dealers looking for it. Seems to be more with those that have autos with their 4.0 motor.

It rattles when in gear and stopped. Not in P or N. or at anything off idle rpm.

A couple weeks ago I found it to be actaully coming from the engine compartment. Directly behind the valve cover where the tranny dipstick tube is, the battery ground cable is bolted to the firewall. At idle and in gear, the motor is a hair rough and it is possible that the ground cable is against the tranny dipstick tube ever so lightly. The vibrations from the motor, transfers the vibs thru the ground cable, directly to the firewall. And with that we hear the rattle as what we will swear is coming from the heater ducting. A simple wire tieing the ground cable tight against the tube will eliminate this vibs/rattle as it is held tight now. Or you could reroute the cable away from the dip stick as long as it will stay away. A couple guys here posted this to be the fix for them after they tried it.

Now, a week ago I started hearing this rattle again, thinking I didn't find the problem after all. So tonight I looked back into it. This time it turned out to be the large wire harness in the plastic loom that is bolted to the back of the V/C, goes around the recess bend in firewall, then to the computer behind the battery. Again at idle rpm, in gear, the motor idles just rough enough that the large wire harness can vibrate against the firewall. It happens when anything just barely touches the firewall, not is tight against it. Hence the vib/rattle sound.
Both the ground cable and this wire harness are both routed in this same tight location at the dipstick tube where the fire wall is recessed to clear the motor. The dip stick tube is what makes this area more likely for this condition to happen as the routing of the wire harness is more confined now. My harness had actually wore the paint off down to bare metal on that corner. Wire tieing both ground cable and wire harness to the tube keeps them away and from vibrating against the firewall.

Sorry for long winded post, but I know many have chased this around with no luck because they are looking behind the dash and I wanted to update with the 2nd possibilty. If you have this rattle, have someone sit in your Jeep, with it in gear, while you slightly push the wire harness tight to that corner (you'll know where I'm talking about as soon as you eye ball it), not to effect it anywhere else. The 2nd person makes it real easy to know if the rattle stops. I say try pushing there just enough to hold it tight against the firewal so you are sure that is where the issue is. Don't want to disturb anywhere else.


Hope this helps.
 

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I just replaced the Neutral Safety Switch- engine runs great, but now rattles just like you said. I obviously altered the delicate spacial relationship between the wires and dipstick while unplugging the old and plugging in the new NSS.

Thanks
 

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Thanks for the post. I have the same rattle on my 03 at stop lights and have been lementing getting into the dash to try to find it. I'll look at the items you indicated.
 

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strange

Mine had the same noise and endless searchs found nothing, I had marked it up to one of lifes unexplained mysterys. :brickwall
Then I decided to do a cheap budget boost , so I did a 2 inch BB and dropped the transfer 1 1/2 and added tires and wheels.
Lifes unsolved squeak/rattle in dash area went away and has not been heard from since. I dont know what one had to do with the other but who am I to argue with success :cheers2:
 

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I get that annoying rattle also. Sitting at a stoplight while in gear it just sneaks up and rattles away; drop the auto tranny in neutral and it immediately dissappears. I'm going to have to look at what you're talking about and give it a quick fix!
 

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I was wondering what that was too. I always thought it was something to do with the suspension. Thanks!
 

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Bingo............yep mine was the main harness tapping against the recess. I zip tied it t the tranny dip stick tube to pull it away.
 

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That's exactly what mine does too. And under throttle up till 1200 rpms. After that no more sound.
thats dead on, and the reply about droppin it into N, that works everytime. i fixed this problem tho with the thread starter's advice and the Jeep is a much nicer ride. I won't say quieter, because after all, it is a soft top TJ.
 

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Add me to the list, I have that annoying rattle behind my dash or so I think. However, my wife is using the jeep right now. I will check out the suggestions later this week.

You guys rock:thumbsup:
 

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Reviving this from the dead to say thanks. I just went outside and noticed the ground wire right next to the transmission dipstick and large harness/loom making contact with the firewall right behind the transmission dipstick. I see where the wire harness removed paint from the body. Going to test it out tomorrow, hopefully the annoying vibration is gone.


If this doesn't work I'm just going to sound deaden the daylights out of everything.
 
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