Loud Noise Hitting Bumps

[SiVisPacemParaBellum]

I purchased a used 2006 Jeep Liberty Limited (with 9k miles on it) a few days ago. It's in great condition, but I've noticed something, and not really being much of a "car person", I'm not sure what it is.

When I hit "big bumps" (e.g. speed bumps, major potholes, etc.) at a "non-slow" (e.g. 20MPH and faster) speed, I hear a very loud noise.

It's tough to describe the noise, other than "very loud", but I'll do my best.

It happens only at the moment that I hit the beginning and/or end of the bump. That is, if I hit a speedbump at about 25 (when I "should" be going about 5-10), I can hear the sound twice (once at first contact with the bump, and once when I'm returning to the pavement beyond the bump).

The sound is quick. It is not any sort of rattle or other "long-lasting" sound.

If I had to describe what it might be, it seems like a very short and quick "grinding"/"vibrating"/"rubbing" sound. It is relatively low frequency; it is NOT a high-pitched squeak.

Also, I can not isolate the sound at a single wheel. In fact, if I had to guess, the sound may be coming from all of them simultaneously.

I have tried making the sound occur by simply pushing down on the vehicle, thinking it may have something to do with suspension, but I'm a lightweight; I do not weigh enough to push down a relatively new Liberty very much.

Note that this sound does NOT occur on all bumps. In fact, this Liberty really feels and sounds great on normal roads. It's only under unusual circumstances that I can hit a bump or hole and hear this sound. However, when I do hear it, it is very loud.

Also, the volume of the sound is static. That is, it's either there (and loud), or not there at all. There is no middle ground.

Thanks in advance!

 

[kjfan18]

Its more than likely your sway bar bushings. Seems to happen to almost all KJ's. Just grease them up real good.

 

[Dave]

SiVis.......Sounds like kjfan is right. You could spray them and see if it stops the noise. Also, you said your kj was an 06 with 9k on it so you are in warranty, so let the dealer replace them???

Dave

 

[SiVisPacemParaBellum]

Responses

Thank you both for your responses.

Is there any particular grease that either of you would recommend?

Yes, it is still under warranty. Is this something a dealer could do quickly, or will I have to leave the vehicle or wait a while?

Thanks again.

 

[Dave]

SiVis.....You could spray it with wd40 just to see if it stops the noise. Then you will know for sure that was the noise.

But I use Endura Heavy Duty Penetrating Grease made by Castle. It is heavier than wd40 and stays put better. It comes in a red/white/blue and purple spray can and i got it at Autozone. I think I saw it at wallymart too. I am under the jeep when I do an oil change anyway so I spray them. Havn't had any noises yet.

I don't know what the dealer will do. They might just spray them with something or they might replace them???

Dave

 

[gordymills]

I have a 2004 KJ with 43K miles. Mine has been doing that since winter set in. We had a warm week (50's) a few weeks ago and it didnt do it. I found that if it's below 40 degrees it seems to do that. I'll try greasing up the bushings and see if that stops it. It's more of a creaking noise when the shocks compress more than normal (beginning of speed bumps and such) and I only seem to hear it from the front wheels.

 

[Corwyyn]

Yeah Gordy I'd say it's your front swaybar/control arm bushings. Just give 'em a good spray with some silicone lube and they should be good, the upper arm bushings you get at thru the wheel wells. And don't forget the two big bushings that are tucked up behind the front bumper.

 

[chirokj]

Mine just started making a squeeky noise when going over speed bumps, especially coming down from them. any ideas?

 

[reload40s]

We finally hit sub 20 degree weather here and right on cue the sway bar bushings started ******** going over bumps. Like everything else "It's a Jeep Thing" and it is part of their charm.

 

[Marlon_JB2]

It's a Liberty thing. They pretty much *all* do it.

Personally I never hear it anymore because I'm so used to hearing it. Dealers around here have those in stock for quick replacement. I got them replaced on my '04 KJ and my sister got them replaced on her '05 KJ thinking it would solve the problem.

It just came right back next winter.

 

[SiVisPacemParaBellum]

Charm

Part of their charm? Alrighty then, I can deal with that.

It's just luck that I happened to purchase this Liberty right when the temperatures in my area plummeted for the first time this winter.

Marlon: Thanks for the extra information. I've been debating whether I should visit a dealer and push for them to replace them, in hopes that the next set would be better. However, I'm now thinking that would just be a waste of time for everyone involved, including myself. I may still talk to the dealer about it, but I won't be as pushy as I was originally thinking about being.

If I go the grease route (and thanks to Dave for a type to look for), I was thinking I would only need to grease the bushings up under the bumper. However, Corwyyn suggests there are other places I should grease as well. If this is true, I could benefit from a little guidance as to what should be greased, where it is, what it looks like, etc. (I'm not as competent about these things as I would like to be.)

 

[Welsh Dragon]

Ha ! a suspension thread - great advice here I'm just wondering if it applies to my rear suspension noise? The front is smooth as silk but I get a popping sound from the rear driving slowly over slight bumps and a louder two tone low moan if hitting large bumps at slow speed. Otherwise drives fantastic tho best car I've owned!

I've got a month left on the warrenty - its it worth getting it looked at in case it's going to be a nasty costly suprise or is it more likely to be a simple cause and remedy or is it "just a Jeep thing"

 

[JeepJeepster]

I would just crawl under it and check it myself. Check that balljoint on the upper A-arm. Torque all the bolts to proper specs. Its probably the shocks.

 

[kj924]

I get a hard hit in the back when going over depressions in the road. It will skip the disk player it hits that hard. It sounds like I am hitting the rear bumpstops......hard! Took the buggy to the dealer and they replaced rear control arm(one with balljoint) and that didn't solve the problem. I knew it wouldn't, but warranty covered it so......

Now its also -20 Celcius( no conversion...don't make me do the math) here, and things are cold, but it shouldn't hit that hard .....should it?

 

[JeepJeepster]

Mine has only bottomed out when I had extended bump stops on to keep the tires out of the fender. I also had a 2.5in lift on the rear though. I took those off and replaced them with air bags.

Its possible that a stock suspension is bottoming out on HARD bumps. If youre just going over speed bumps then no, it shouldnt be bottoming out.

 

[Welsh Dragon]

Jeepjeepster - I take it that the ball joint on the upper A - arm you refered to is at the rear? And as you say symptom occurs when driving very slowly over large bumps, so definatly not bottoming out. It could well be the shocks as the two tone noise seems to match the movement of the shocks compressing and then decompressing. Only 24000 miles on the KJ tho would expect higher mileage out of the shocks myself. Has anyone had to replace shocks so soon or know of a common complaint with them or the set up?

 

[fujitsubo]

Yeah Gordy I'd say it's your front swaybar/control arm bushings. Just give 'em a good spray with some silicone lube and they should be good, the upper arm bushings you get at thru the wheel wells. And don't forget the two big bushings that are tucked up behind the front bumper.

I recently have the same noise but when going over big speed bumps, it sounds like the front is rubbing something, as opposed to a squeek. The noise reminds me of a lowered car going over the bump. What i can't figure out is how would the sway bar bushings make that noise instead of the lower or upper control arm bushings?

 

[LibertyOrDeath]

Does white lithium grease work?

 

[Redneck]

Kj problems

What would make my 06 jeep liberty bog down when I hit a bump and when I go from 35mph and up

 

[HoosierJeeper]

Welcome to the forum - if you start a new thread you'll get a better response!