IronCobra

If you recently had your LCA Bushings changed or had the bolts loosened and/or removed and you are getting a popping sounds when coming to a stop or when stopping in reverse I have narrowed this sound down to the LCA bolts not being tightened. They required quite a bit of tightening (possibly with an impact wrench) or a torque bar.

This sound is from your LCAs moving forward and backwards as you stop and go. If they are not VERY TIGHT they will gradually move backwards as you drive or come to a stop and POP forward when you stop as your backing up or turning.

I am posting this because there are ALOT of people that have asked this question and very few real answers have come out.

Many people think that the popping sound is coming from their Brake pads shifting.

Here is a way to distinguish between the two sounds.
-Brake Pad Shifting sorta sounds like Tapping a nail head against concrete

-LCA (or subframe) Popping sounds like tapping a metal hammer against concrete.

The Bolts that go through the Control Arm Bushings (Circled in Yellow) are what need to be VERY tight. VERY VERY tight! I mean Super Tight!

AME_VIP

iTrader: (2)

good post.

I recently installed new supra TT LCA's and the popping/knocking is slowling coming back.

Gotta be loose bolts.

IronCobra

Probably.. I had new LCAs installed and I had the popping right after. I took it back, they tightened the bolts and it went away for a few months. It's slowly coming back though. I'm going to have them tightened again.

LexAnt

iTrader: (2)

mite wanna also double check to see the subframe bolts are tightened as well. I had the usual clunkin/poppin noise, so i replaced the bushings, it was still there. So i had my mechanic tighten every possible bolt and found the subframe mount bolts to slightly loose, after tightening it made a big difference, no more sound and the front felt tighter in steering.

IS0LD0UT

iTrader: (1)

any pics of these bolts. I had originally thought my poping noise was due to the brake pads? Not true?

vipsoarer

once you get them torqued. lock-tite those suckers!

pilip99

thanks for posting this bro, i have this exact problem, im gonna investigate it today

soarer5780

i same problems i installed ls brakes on mine and was wondering what it was thanks for the post

IronCobra

Brake Pad Shifting usually makes a Clicking noise. Popping comes from Metal sliding and popping back into place, generally from the LCA bolts working their way loose or not being tightened in the first place..

-Brake Pad Shifting sorta sounds like Tapping a nail against concrete

-LCA (or subframe) Popping sounds like tapping a hammer against concrete.

AME_VIP

iTrader: (2)

One other clunking that I experienced was a loose caliper bolt.

I was getting clunking when braking, and over bumps. It turns out one of the two caliper bolts had come loose slightly and was causing the caliper to shift. I fixed that but now my clunking is coming back slowing, louder each week but just over bumps.

I'm going to get under there and torque every bolt I can reach.

LexGS

I just purchased a beautiful 00' GS300.
I noticed that I was getting a plinking sounds every once in a while. I would get it EVERYTIME when I stopped the car and put it in Reverse and then stop "PLINK!" As if someone had hit my caliper with a hammer dead on the flat surface.

I thought that maybe the pads and the spacers were worn out and creating play within the brake pad slot, but from reading all the posts I think I am wrong and will check the those bolts that you mentioned.

Will let you know the results once I get around to it.


Thanx again

LexGS

SharpCreas

I wonder this is something that you have to do every so often. The bolts never stay tight?

IronCobra

It would appear that they do loosen after time. My 93 GS300, 95 SC400, and current 97 SC300 all have the same issue. On my 97 it started after I changed the front LCA bushings.

Even though this is probably the problem, while the car is in the air be sure to have ALL the chassy bolts tightened.

AME_VIP

iTrader: (2)

I discovered what my loose suspension was this time. The drivers side lower sway bar linkage nut had worked its way loose. I tightened it up and tight as possible and no more noises.

Lesson: Torque every bolt/nut to spec !

TMaxxTim

I know this is a little old, but I had the same problem awhile back and it was also my caliper bolt. I guess sometimes you may think they are tight, but the braking either pops the caliper out and lets you tighten more or something. Anyways, tightened it back up and haven't had the problem since.