amcdonal86

Hi,

I've had this popping sound that was hanging around for a long time on my '97 LS4 from the passenger's side of the front suspension area. It was really annoying, so I replaced my lower ball joints. This did not help.

I had read on here that sometimes the lower control arm nuts can become loose. Today, I tried tightening the nut. To my surprise, it did not seem that tight (it was on there, but I was able to turn it more with my breaker bar with not too much force).

After I did this, the noise seemed to occur with less frequency, but with much greater intensity. I mean, this is a pop that you can feel through the entire car! Previously, it would vary in intensity--sometimes it would be a gentle "click", other times it would be a light "crunch", and occasionally it would sound like a loud "pop". Now it's all loud pop!

I think this indicates that I have isolated the problem. But my question is, how do I fix this popping sound? Does this mean my lower control arms are bad? When I tighten the front nut, is it just spinning the entire bolt around, or am I really tightening it?

Thanks in advance!!!!!

Previous thread about problem:

https://www.clublexus.com/forums/ls4...ints-last.html

rob22

I had a popping/knocking sound in my 97LS that I finally got resolved last week. It was an occasional popping noise that occurred either when I went over speed bumps at low speed or ran straight for awhile, then made a turn (like entering an on-ramp). The sound was from my left front and it sounded like a pop or knock...sort of like you're cutting veggies, metal knife knocking against a wooden cutting board. Difficult to describe these sounds . It didn't shake the whole car though...like you describe.

I checked all the joints and nothing seemed loose. I couldn't generate the sound by bouncing the suspension, shaking the spindle...anything.

First replaced the sway bar bushings, no change.
Next replaced (rebushed) the strut rods, as I've learned from here that these are common culprits, but no change.
Next replaced lower control arm balljoints and tie rod ends, new alignment, no change, still knocking.
Next tightened subframe, crossmember, steering rack nuts/bolts, still no change.


All this time I was getting conflicting info from mechanics. One guy said it was my UCAs, another said my strut mounts.

Last week I rebuilt the struts. New shock absorbers and strut mounts. This finally took care of the problem, the knocking is gone.

My struts were (to the best of my knowledge) original with 200K miles on them. The knocking had been going on since I purchased the car at 170K. There was no oil leakage from the struts, no weird tire wear, car tracked straight. The ride was soft and it leaned in corners somewhat but that seemed consistent with the "floaty" ride of the LS.

Even with my struts removed, springs disassembled, I was getting conflicting info. I took the shock absorber to the dealer service, a tech checked it out and said that it was soft but correct. Then I took it to my indie mechanic (the guy who had previously insisted that the struts were fine, don't waste money on them, it's the UCAs); he looked at the shocks and said that they were toast, replace them!

I installed KYB GR2 shocks, both front and rear.

Hope this helps. Do you have a torque wrench? It's very important if you're doing your own wrenching. Being able to turn nuts "a little more" with a breaker bar doesn't give info as to if stuff was loose or tight to begin with, makes it more difficult to diagnose your problem. Good luck with it.

amcdonal86

Thanks for the info. I don't think this sounds like my problem, though. I also only have 112k miles on it, and when I replaced my upper strut mounts, my struts were not leaking or anything so they still seemed to be good.

rob22

I understand. I didn't answer your question...which nut on the LCA are you tightening? Is it the one that sets your camber? The attached might help.

amcdonal86

Thanks for the diagram. I am tightening the nut on the opposite side of the camber bolt. I guess what I want to know is what are symptoms of bad LCA bushings.

amcdonal86

Really? Nobody has any idea what the symptoms of a bad LCA bushings are?

atoyot

lol, well, i thought based on what i have read here it's a clunking sound when going over bumps.

amcdonal86

Hm.... but I don't have clunking over bumps. I have clunking/popping when braking hard, or switching from drive to reverse. And no, it's not the brakes because I replaced my front brake pads and shims and fitment kit and put plenty of grease!

That, and tightening the LCA bolt made the noises much more loud. So my conclusion is it MUST have something to do with the LCAs! But since I expected the noise to go away by tightening the LCA bolts, does this mean that since it made the noise worse, that my LCA bushings are, indeed, bad?

amcdonal86

Well, I decided to go ahead and order the right front lower control arm with all of the washers and bolts (except for the large camber bolt) from Sewell Lexus. We will see if it solves the problem! I'll probably install it on Friday.

python

iTrader: (4)

lower ball joint

amcdonal86

That's what I thought, too, but I replaced those last week with no change in the noise.

atoyot

a little side tangent here, but since the OEM ball joints seem to fail pretty quick, would a NAPA or some other replacement be just as good as OEM?

rob22

When you replaced your brake pads, did that cause any change to the sound? When I bought my car it had a high-pitch clicking noise coming from the front when I applied the brakes. I took the pads off and noticed that they were installed upside down. It's subtle but there's a chamfer on the pad material that has to go in a certain direction. It is possible to install them upside down. I corrected the orientation and repacked them with the brake lube and the noise went away.

Hope the new LCA does the trick.

amcdonal86

No, the brake pads didn't cause any change whatsoever. The pads are installed correctly with all new hardware and plenty of grease.

I will let you all know what happens with the new LCA.

amcdonal86

Replacing the right front LCA has fixed the popping problem.