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Resonating noise at 50-60 mph.
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Author:  ISpy [ Sun May 27, 2007 7:15 pm ]
Post subject:  Resonating noise at 50-60 mph.
2005 Liberty, Auto, 3.7l. Hello Everyone. I'm a new Liberty owner and new to this great site. I have a few issues with my new-used Liberty that I am working out. Stuff like noises, gas mileage :) etc. One thing that is really bothering me is a resonating noise when Im accelerating through 50-60 mph. I hear a loud-er, low sounding noise, like resonation coming from the back passenger side as if its resonating through the tailpipe. If I'm cruising at 55 mph the sound will stay as long as I'm on the gas. In other words, at the 50-60 mph range I can tap the gas pedal and get the noise also. Is this normal for the Liberty? Is this a transmission thing having to do with the back transfer case? Has anyone else experienced this? Thanks for any helpful replies and it's great to have a site like this with fellow Libby owners to consult with.

"Give me Liberty or give me death"!!!
Author:  tjkj2002 [ Sun May 27, 2007 10:09 pm ]
Post subject: 
Could be just tire noise,my MT/R's really howl at about 45mph(alot louder then any other speed).Also it could be the intake making the noise,sucking the air in type of noise(like a vaccum cleaner).Does it have the factory tires on it? Have you checked the rear driveshaft u-joints/front driveshaft CV's?Fluid level in the front/rear diff,and transfer case?Those could all cause some noise to.And welcome to the site!
Author:  ISpy [ Mon May 28, 2007 5:40 pm ]
Post subject: 
Thanks tjkj2002 for the reply but I have ruled out the tires because I can reproduce the noise just by tapping on the accelerator while in the 50-60 mph coasting range. Accelerating through that mph range is constant but while coasting between 50 to 60 mph the noise will stop and I can reproduce it again with slight taps on the accelerator. This leads me to believe it is something in the transmission or transfer case? Anyone else ever experience this problem. Any more suggestions? I'm going to have the fluids checked next week with oil change but do you think the transfer case can cause this noise only at certain mph speeds? Does anyone elses Libby do this? and thanks for the welcome...it's a pleasure to be here.
Author:  ATXKJ [ Mon May 28, 2007 6:33 pm ]
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tjkj mentioned all the variables -but I'd focus on the rear differential - different loads on acceleration, deceleration.
Author:  Metrowest_Kev [ Mon May 28, 2007 10:05 pm ]
Post subject: 
I only have wind and engine noise at that speed. MPG is pretty good (19 mpg) when cruising on the highway.
Author:  hyedipin [ Tue May 29, 2007 9:14 am ]
Post subject: 
I have the same noise, only when I tap the gas pedal lightly while coasting at 60mph. Or there is exact speed maybe 62mph. When I tap the gas pedal it makes a howling noise (apparently only I can hear, my wife keeps telling me I am crazy with these noises on the jeep). Yes, it is there, it is like a wind noise, but only happens when I tap. It could be the RPM+Speed combination and you are giving some gas, but it doesn't do anything kinda situation.. :evil:
Author:  jcphoto20 [ Tue May 29, 2007 9:59 am ]
Post subject: 
[quote="Metrowest_Kev"]I only have wind and engine noise at that speed. MPG is pretty good (19 mpg) when cruising on the highway.[/quote]

thats pretty good for most people on here with a 3.7, but not nearly as good as you could be getting.
Author:  FreeJeep [ Tue May 29, 2007 10:47 am ]
Post subject: 
Sounds like the rear drive shaft / u-joints to me. I was getting a nasty vibration / hum coming from the rear until I changed my u-joints. All is better now, accept when I try to lift it "Just a little more to level it out" :roll: It messes with the angles too much and the noise comes back.
Author:  dog_party [ Tue May 29, 2007 12:18 pm ]
Post subject: 
Could it be exhaust? Is there an aftermarket exhaust system on your new/used Jeep? I've seen different aftermarket exhaust systems create a baffle that put out a horrendous howl/vibration at very specific speeds.

It's unlikely this is the case if you have a stock exhaust (that isn't damaged). But I thought I'd put it out there.

Welcome to LOST!!
Author:  ISpy [ Wed May 30, 2007 11:24 am ]
Post subject: 
dog_party, When I bought the Jeep 3 months ago it had the original 'silencer' muffler on it and the resonating noise was there so I changed the muffler to a 'free-flowing' style muffer and I still have it. I was thinking muffler too but that change has ruled it out. The muffler change with free-flow (no baffles) gives it a more throaty sound without being too loud. I like that sound but it still makes a low howling kind of sound between 50-60 mph acceleration or cruising and tapping the gas.

hyedipin, that sounds like what I have. Have you done anything about it? I'm going to check axles, diff fluids, etc when I change oil.

I also get a wind sound at any speed over 50 mph coming from my passenger back window because the bottom seal isn't covering the gap all the way. Took me a while to figure that one out.
Also, got a sqeaking noise from what I thought was the back gate but it turned out to be the back passenger seat hook. I wrapped thick silver electrical tape around the hook, slammed it up in place and that stopped it.
On the back gate window I put a strip of door weather seal tape (the thin spongy type) along the bottom of the window where it connects to the gate and that took care of a little crunching noise there.
Author:  jcphoto20 [ Wed May 30, 2007 2:04 pm ]
Post subject: 
thats wierd, i dont have any rattles or squeaks or any weird noises. but we dont flex ours much.
Author:  hyedipin [ Wed May 30, 2007 3:42 pm ]
Post subject: 
ISpy wrote:

hyedipin, that sounds like what I have. Have you done anything about it? I'm going to check axles, diff fluids, etc when I change oil. .


No, it wasn't loud enough to bother me. I always have radio on, so I rarely hear these stuff. If it is louder than that, enough to bother you with radio on, i would do deeper investigation.
Author:  cobrastangs [ Wed May 30, 2007 11:20 pm ]
Post subject: 
FreeJeep wrote:
Sounds like the rear drive shaft / u-joints to me. I was getting a nasty vibration / hum coming from the rear until I changed my u-joints. All is better now, accept when I try to lift it "Just a little more to level it out" :roll: It messes with the angles too much and the noise comes back.


Sounds just like what mine was doing. It ended up being the U-joint.
Author:  hyedipin [ Thu May 31, 2007 11:33 pm ]
Post subject: 
Today while I was driving in NJ, I tried this and found the sweet spot (or sour spot) when it makes the darn howling, whirrring, spinning, revving noise, or whatever you'd like to call it.

1800rpm, 58mph.
Touch, and i mean LIGHTLY TOUCH the gas pedal, you hear it.. WRRRRRRRR or WHOOOOOOO
Touch a bit more and it is gone (either rpm goes above 2+ or drives 60mph+ or slower, any other combination it is not there!)
AC on or OFF , it is there.
Did not try it in 4x4FT, but it is there in 2x4.

pls try.
Author:  ISpy [ Fri Jun 01, 2007 7:15 pm ]
Post subject: 
Hyedipin, I get the same low whooooo or wrrrrrrr noise between 52-58 mph. Anything below or above it goes away. It seems to be resonating out of the left back side from the tailpipe. That's why I'm thinking it's more engine or transmission related instead of joints or wheels but who knows? The sound I get above 58 mph is a different transmission sound that seems to have shifted into a higher gear. Maybe something right before that transmission change to higher speed? I only have 4X2 not 4X4 so can't try that. I'm getting oil changed soon so I'm going to have them check joints and fluids. Maybe that will fix it.
Author:  Jeepjeepster [ Fri Jun 01, 2007 7:51 pm ]
Post subject: 
Sounds normal to me. Only reason I say that is because I just got a FlowMaster and it drones at that speed when I give it gas..
Author:  Jeepjeepster [ Fri Jun 01, 2007 7:52 pm ]
Post subject: 
hyedipin wrote:
I have the same noise, only when I tap the gas pedal lightly while coasting at 60mph. Or there is exact speed maybe 62mph. When I tap the gas pedal it makes a howling noise (apparently only I can hear, my wife keeps telling me I am crazy with these noises on the jeep). Yes, it is there, it is like a wind noise, but only happens when I tap. It could be the RPM+Speed combination and you are giving some gas, but it doesn't do anything kinda situation.. :evil:


That howling noise is also normal. All four of our jeeps do it given that situation. Ive grown to like it for some reason.
Author:  hyedipin [ Fri Jun 01, 2007 8:43 pm ]
Post subject: 
ISpy wrote:
Hyedipin, I get the same low whooooo or wrrrrrrr noise between 52-58 mph. Anything below or above it goes away. It seems to be resonating out of the left back side from the tailpipe. That's why I'm thinking it's more engine or transmission related instead of joints or wheels but who knows? The sound I get above 58 mph is a different transmission sound that seems to have shifted into a higher gear. Maybe something right before that transmission change to higher speed? I only have 4X2 not 4X4 so can't try that. I'm getting oil changed soon so I'm going to have them check joints and fluids. Maybe that will fix it.


Keep us posted. Good luck!
Author:  ISpy [ Mon Jun 04, 2007 7:11 pm ]
Post subject: 
Jeepjeepster, Why do you say it's normal? Not all jeeps do it. What would you say causes that droning howling noise only at certain speeds while tapping the gas?
Author:  gopherbeats [ Mon Jun 04, 2007 10:09 pm ]
Post subject: 
This just started to happen to me after I installed my lift. I have not had any time to think about what may cause it. But there are tons of variables.
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