Scopedog

Hi! I'm driving a stock 2010 Wrangler Unlimited Sport hard top with automatic transmission.

I went off-road with it for the first time at Anza Borrego Desert State Park on Saturday. I drove around the trails for about three hours and had an insane amount of fun. On my way back home I noticed my alignment was off and I also noticed an unusual but rather faint rattling/buzzing sound when I press the accelerator. I don't hear it in reverse or while idling or once I'm at speed. Once I got home I had a friend sit inside and press the accelerator in neutral while I checked out the engine and I couldn't hear it from the outside at all nor could I see anything wrong with the engine. Since I can only hear it when I'm inside it seems like it must be coming from the transmission.

I made an online appointment with the dealership for Monday at 11:45, so I took my Jeep in today and told them about the noise and the alignment problem. They called me saying it was ready to pick up at around 5pm and the paperwork they gave me says they fixed the alignment but regarding the rattling noise it says "NORMAL OPERATION AT THIS TIME, OPERATING TO MANUFACTURER SPECIFICATION". They said I should bring it back if the noise gets worse, but otherwise everything is fine.

I was given a loaner while my Jeep was being inspected and it happened to be a Wrangler Unlimited X with a soft top and the loaner definitely didn't have the rattling/buzzing sound, so I know its not in my imagination.

Although the sound is a little annoying, I'm not that worried about it and I'm glad I got it documented in case something happens in the future. In any case, I was hoping the knowledgeable contributors of this forum might have some insight into my problem and whether I should be worried, and if so, suggestions of how I should proceed. Please let me know if you need any further details and thanks for any help!

mkjeep

Probably a heat shield on your exhaust, check your crossover pipe, it has about 8 tack welds on the shield. If one weld cracks it'll cause a buzzing rattle sound. There are other heat shields aswell, though the crossover pipe one took me 3 days to find .

Blackmetal

You know I also hear a ticking sound on my JK.
I too have an auto but its an 07.
And I only hear the ticking sound when my doors are off and I am close to a wall.(you know the whole echo thing)
I wonder if this is a problem? Since I have no mechanical experience I cannot give you any advice.

mkjeep

One possibility of that "tick" could be an exhaust leak , loose bolts and or a cracked manifold. Mine cracked , was covered under warranty. Driver side usually, 20,000m later it's doing it again, probably cracked again.

Scopedog

Hi! Thanks for the feedback! Would the crossover pipe or heat shield problem you describe only cause rattling/buzzing during acceleration?

Also, where exactly are the tack welds you're referring to and which pipe is the crossover pipe? I took a look at all the visible exhaust components (exhaust pipe to engine) from underneath and didn't see any conspicuously fragile or loose welds on the piping or heat shields. I also had a friend press the accelerator in neutral while I was underneath listening from different angles and I didn't see or hear the rattling/buzzing. I only hear it from the inside. Even opening the windows while driving makes it hard to hear.

Can you identify the suspected problem area with either of these pictures?

http://moparestore.trademotion.com/m...K/i2234468.gif
http://moparestore.trademotion.com/m...K/i2245510.gif

Again, your assistance is greatly appreciated!

Scopedog

Update on my rattling/buzzing:

I took my Jeep to a different dealer today for a second opinion. I initially rode with the Service Department Manager while he drove it and he said he didn't hear anything unusual. I went for broke and told him that I had done some research online and that a common reason for the noise I am hearing is a loose tack weld on the crossover pipe heat shield or a problem with the knock sensor. He said he would take a look at those and also he would drive another similar JK to see if it sounded different.

After having it for about six hours they called me and told me that they didn't find anything wrong and that everything was tight. They also said there was evidence of bottoming out on the passenger side splash shield but that the damage was superficial.

I'm going to let it go at this point and if it does get worse or become a bigger issue I have plenty of documentation that it was brought to the dealership's attention.

mkjeep

On your first pic #8 or 6, the numbers are tiny and I need reading glasses, it's the pipe that goes across the bottom of the jeep in front of the tranny. It has a heat sheild on it. There are approximately 8 tack welds on it and unless you inspect each one closely you won't see the crack. I took a flat screwdriver and just pryed the sheild away a little from the pipe at the weld. Some people put band clamps on it and tighten down. Also check and see if any of your shields on the body tub are touching the exhuast pipe and or muffler. There is also a shield over your manifold that can cause a rattle. Mine rattled under acceleration and actually it sounded like I was having tranny issues. From your decription it sounds like an exhaust rattle somewhere. I bet they didn't check the crossover pipe good.

Scopedog

This advice makes a lot more sense now, thanks! I'll take a closer look at my heat shields tomorrow or this weekend. If I find the culprit, I'll probably go the band clamp route. Thanks!

MaineRubi

If you can only hear it inside when accelerating, check the plastc grommet on the steering column in the engine compartment. Mine slipped about 1/8 inch and sounded like an exhaust leak on acceleration. The dealer told me the same thing about it.

Scopedog

You were right! Yesterday morning I inspected that grommet before heading to work and I tapped it with a hammer but it didn't move. There was about half an inch of grease on the end of it so it looked like it had moved but I needed to go to work, so I didn't mess with it any further. This morning I went under the Jeep again and took off a splash plate to inspect the crossover pipe heat shield. It seemed like one of the tack welds was loose so I pried it away from the exhaust but the sound continued. I poked around at some of the other tack welds, and still found nothing loose. I went back to the steering grommet and noticed that the grease mark was larger so I decided that it had definitely moved. I tapped it harder than before with a hammer and it went back in. It seems like the grommet isn't very well secured and that this problem will occur again.

For everybody's info, the grommet in question is highlighted in this picture: