As the subject reads, I am trying to identify and fix an annoying rattle on my 2007 JKU with about 134,000 miles on it. I expect an old high miles Jeep to make some noise, but its finally getting on my nerves.

I first noticed it after I had the alternator replaced about 131k. My mechanic (life long friend of my Dad) said the water pump was noise to keep an eye on it. The noise got a little worse and then 2k miles later the water pump went, and was replaced by the same mechanic. When I got it back I noticed that the noise was A LOT better, but not completely gone and over the past month or so the noise has gotten a little bit worse.

I notice the rattle when accelerating at around 2000 rpm and then when i settle into a cruising speed it seems to stop. Its not constant though. In my opinion is sounds like metal to metal. I as thinking loose heat shield or maybe a muffler hanger? Any help diagnosing and fixing the problem would be appreciated. I will try to capture some audio/video of the issue but it may not help as it would be directional at all.

 

Is it an rattle or squeal? Since most work was done up front did you check the tension pulley?

 

It is definitely a rattle, and it happens when accelerating briskly (but not flooring it). Only between 1500 an 2100 rpm. I can cruise at 2000 rpm without a sound. Also sounds like maybe its only in gear 1-3(?). Not sure about that last part though. Im going to look for a write up on how to check the idler pulley and see if that helps out.

 

I've had an 07 before as well and noticed that on some of the heat shields, they have metal versions of zip-ties to hold the heat shields in place, etc. Those heat shields are spot-welded closed. Sometimes those spot-welds break, but you wouldn't know because the metal "zip-tie's" are strong, they don't necessarily dangle when broken, etc. So, you have to look close and you'll see... That being said, I've had those ties actually rattle so bad, you could clearly hear it.

Now, not saying that's the root of your problem, however - it is a suggestion, and could just be your solution.....happy hunting

 

Believe FoxRacingJMC is on the right track, had similar problem on my 2009, rattle can be heard when you close the rear door or if you kick your tailpipe slightly.

 

didnt get a chance to check the heat shields today, but will most likely get to check them tomorrow. If anyone has a photo of the area which I am looking at it would be helpful. Thanks for the info guys

 

this was the best pic I could find...

 

Get a rubber mallet, crawl under your Jeep, and start tapping under there. You'll likely find the rattle pretty quick.

Good luck and let us know how you make out?

 

Ok, not to bring a mini van into this. But my wife had a 2007 grand caravan. It had the same problem at about 130000. (Same 3.8L engine as the 2007 JK) I tried everything and could never font it. It was just like you described. I even took the intake off and cleaned everything, checked heads and lifters, etc. the van is gone now, but the sound is still mystery. Hope you find yours.

 

X2 on this. I had 2 welds broken on this shield. Took the skid plate off, welded them up and no more rattle.