Rattling noise at idle, back of Jeep, sounds like exhaust?

baddabing · **Posted:** Fri Feb 19, 2010 9:28 am

We have always had this rattling noise at the back of Jeep when at idle, when you touch the throttle slightly or start to drive, it goes away. It sounds like it might be the exhaust? Can anyone pin point what this probably is?

Thanks very much!

flman · **Posted:** Fri Feb 19, 2010 9:30 am

baddabing wrote:

We have always had this rattling noise at the back of Jeep when at idle, when you touch the throttle slightly or start to drive, it goes away. It sounds like it might be the exhaust? Can anyone pin point what this probably is?

Thanks very much!

Motor mount, left side most likely. Does it sound like grinding?

No.2KJ · **Posted:** Fri Feb 19, 2010 9:58 am

Mine is doing the same thing. It's been to the dealer twice and they can't figure it out. I got sick of being without my jeep for a week at a time and gave up. I've learned to live with it. If it's a motor mount thats a different story though... Good luck!

linewarbr · **Posted:** Fri Feb 19, 2010 10:02 am

Where on the Jeep is the moise coming from?

racertracer · **Posted:** Fri Feb 19, 2010 10:22 am

It’s probably a pebble caught inbetween the protective heat shields underneath the vehicle.

Look in-between your protective heat shields on the rear passenger side of the jeep close to the exhaust.

Run your finger in there along the side and see if you feel a loose pebble or object in there and remove it, do it when the exhaust is cold.

The heat shield is connected to the sides of body and not on the exhaust.

Use a small twig or something to reach in there and knock the crud out.

Solved one of the most annoing noises I had.

Let me know if this helped you also.

BVCRD · **Posted:** Fri Feb 19, 2010 10:41 am

I will tell you what it is.... it is the tailgate door. I have tracked mine down to the rubber moulding/weatherstrip on the passenger side by the door latch. If you spray a little WD40 on the area so that the door will slide on the rubber when the door flexes, it will go away. Apparently, the frame twists a little and or the weight of the door alows the hinges to sag a tag over time and when that rubber drys out, there is no smooth slip between the 2. Try it. Mine was making a sort of high pitch sqeek that drove me freakin nuts.

PS....don't forget to spray some on the big honking piece of rubber that sticks up and that the rear window closes against.

flman · **Posted:** Fri Feb 19, 2010 11:19 am

Does, it do it in park?
Does it do in in D or R with you foot on the brake?
Does it do it while you are cruising down the road?
How many miles are on you CRD?

I have 2 of these, and the higher mileage Jeep makes a noise with the tranny in gear, and foot on the brake at idle.

I still need to install the left motor mount I bought several months ago :jester:

baddabing · **Posted:** Fri Feb 19, 2010 4:20 pm

racertracer wrote:

It’s probably a pebble caught inbetween the protective heat shields underneath the vehicle.

Look in-between your protective heat shields on the rear passenger side of the jeep close to the exhaust.

Run your finger in there along the side and see if you feel a loose pebble or object in there and remove it, do it when the exhaust is cold.

The heat shield is connected to the sides of body and not on the exhaust.

Use a small twig or something to reach in there and knock the crud out.

Solved one of the most annoing noises I had.

I just love this web site...you ask a question and almost instantly you get people willing to help! If it wasn't for this site, I probably wouldn't own this Liberty!
Thanks!

From the sound that I hear, it does sound like it could be a small pebble or something jammed in an area described above. I am pretty sure it's not the rubber seal at the back door. I know it's not a grinding noise, I will check the engine mount if I ever hear that though. I will reply back this weekend and let you know what it is!

Let me know if this helped you also.

BVCRD · **Posted:** Fri Feb 19, 2010 4:36 pm

While it could be some foreign object wedged somewhere, please just try lubing the rubber back there. I did as you did, checked exhaust clamps, grabbed stuff and gave thing a yank looking for loose parts. The sound mine produced sounded metalic in nature. It was the harmonics from the back glass vibrating on the hardened rubber seal.

baddabing · **Posted:** Wed Feb 24, 2010 9:29 am

I was surprised to see how much sand / dirt was sitting on top of that heat shield. I also stuck the garden hose in their to try and wash most of it out. It seems that it is about 90% better. I do get a little bit of rattling, but not nearly as much as I did. I will see how it is over the next while. I think I will lube up the the rear window seal as well and try and eliminate anything that could contribute to this annoying sound.

BVCRD · **Posted:** Wed Feb 24, 2010 9:31 am

baddabing wrote:

I was surprised to see how much sand / dirt was sitting on top of that heat shield. I also stuck the garden hose in their to try and wash most of it out. It seems that it is about 90% better. I do get a little bit of rattling, but not nearly as much as I did. I will see how it is over the next while. I think I will lube up the the rear window seal as well and try and eliminate anything that could contribute to this annoying sound.

Glad you got most of it figured out. On mine, the sound was sort of metallic in nature, like a really dull chalk on the blackboard. Made my hair stand on end and gave goose bumps.

racertracer · **Posted:** Wed Feb 24, 2010 9:36 pm

The other problem is that the heavy muffler shakes from side to side like a whip near the flange connection.

I took everyones suggestion that had this same problem before me and replaced the muffler with an inexpensive lighter 2 1/2" Dia. one, which cost me about 120 dollars installed.

Never regretted it.

stevesmith7 · **Posted:** Thu Feb 25, 2010 7:44 pm

BVCRD,
Tell you what I wasn't sold on your fix but it was so easy I tried it and my noise is gone. For me it sounded like a metallic chirp when I hit small bumps at low speed when cold. Put some rubber dressing on the weatherseal and all's quiet. I would have never found it. Thanks.

BVCRD · **Posted:** Thu Feb 25, 2010 8:00 pm

stevesmith7 wrote:

BVCRD,
Tell you what I wasn't sold on your fix but it was so easy I tried it and my noise is gone. For me it sounded like a metallic chirp when I hit small bumps at low speed when cold. Put some rubber dressing on the weatherseal and all's quiet. I would have never found it. Thanks.

I was pretty amazed too. I just about tore the back end apart underneath trying to find/reproduce it. Wasn't happening. In desperation, I headed into the cargo area. Glad to be of service. It will come back. But now you know. :BANANA:

BBB · **Posted:** Sun Feb 28, 2010 10:50 am

We have replaced the rear rubber muffler/ tailpipe hanger (twice) that was causing a low dull rumble/ rattling at a idle.

Both times the replacement only lasted a few weeks before the rrrrrrumble/ rrrrrrattling came back. Apparently the rubber hanger is too soft (gasser version?) for the vibrations caused by the deisel engine. Vibrations transmitted thru the exaust wears larger holes in the rubber hanger then the exaust vibrates. I'm going to fab a new one out of reinforced rubber belt or similar material when I get a chance. For now I just used a worm clamp to compress the muffler hanger together. A lighter exaust would probably help the hangers last longer. :2cents:

BVCRD · **Posted:** Sun Feb 28, 2010 12:39 pm

65000 miles and my rubbers are fine.

dgeist · **Posted:** Sun Feb 28, 2010 3:26 pm

BBB wrote:

We have replaced the rear rubber muffler/ tailpipe hanger (twice) that was causing a low dull rumble/ rattling at a idle.

A lighter exaust would probably help the hangers last longer. :2cents:

Probably right. You should take the muffler out. It'll be lighter and it'll perform better with better fuel economy, too

Rattling noise at idle, back of Jeep, sounds like exhaust?

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