2006 LS430 ML, 153K miles

I've searched and searched for answers to this to no avail. I have a rattling noise coming from the front left area of my '06. It happens when going over bumps, or going over rough pavement, it's best described as a metallic rattling noise.

I spent a lot of time trying to chase this down, and have done the following:

• Replaced both front shock assemblies (they needed it anyway)
• Replaced the lower ball joints
• Replaced the outer tie rods (kind of had to, they wouldn't come off the lower ball joint!)
• Replaced the sway bar end links
• Replaced the sway bar bushings
• Took apart the front left caliper and replaced the pads while I was in there, also replaced the anti-rattle (ha!) spring and retaining pin. Replaced the same items on the right, but didn't pull the caliper off. I even replaced the caliper bolts because you're supposed to. This was to make sure that the pads weren't loose and rattling. Interesting to note: the rotor isn't attached to the hub by a screw, it's just kept in place by the tire. First time I've seen that.
• Wheels have been rotated, so it doesn't seem to be wheel related. (Side note: there are "Ironman" tires on the car, is it just me or are those cheap and noisy?)
• Checked to see if maybe the wiper assembly was loose. Nope.
• Heard about rattles in the steering u-joint, but my indie Toyota/Lexus shop said it was solid.

I had it in yesterday to do the timing belt/water pump/pulleys/idlers/thermostat/cam seal and they thought the shock needed to be checked since they're the ones who installed it. He was thinking maybe they didn't seat something correctly. So they tore it apart and put it back together and that wasn't it, which is good because that's kind of a bad mistake to make. (I figured it could have been the upper shock mount, but no). They spent a bit of time looking all over, and it seems that the suspension is solid. The noise remains.

This weekend if time permits I'm going to check the heat shields and whatever mounts I can see, and for anything loose. Unfortunately I don't have a lift but I do have jacks and jack stands. I'm also going to try lifting the front and set up some kind of lever against the bottom of the tire to try to induce some vibration and maybe pinpoint the noise. The shop also wants me to bring it back because I think it's annoying them that they can't find the problem! He said it's probably something cheap and stupid rattling around in there. I wonder if someone didn't drop a socket wrench in there at some point in the past.

I wonder if it's in the control arms, but they didn't tell me that they thought that was the problem, but I'll ask next time.

Any other suggestions of things to check? It's definitely coming from the front left; if I hit a bump I can hear the rattle before the rear hits the bump, so it doesn't seem like one of those noises that's transmitted along the frame and makes it sounds like it's coming from somewhere else.

Thanks!

I have an 06 with what sounds like the same problem. My mechanic isn't sure what is causing it either. He suggested replacing the entire lower control arms ($250/each) but I'm going to try replacing the rear bushing (only one of the bushings is replaceable on the lower control arm). I picked up a pair on Amazon for around $100 (part no. 48655-50012). There are threads on replacing the lca bushing. Will send an update after it's done.

I can't attest to their quality but they are available, fiarly inexpensive too...
https://www.moog-suspension-parts.com/moog-k201684

Edit- Rockauto sells them for $12 ea.

Have you done steering rack bushings? I've done those, sway bar bushings and rear lower control arm bushings, everything appears fine for the rest. I assume it's a strut mount but not sure. Stupid noise makes me want to sell my 04. What shocks did you replace with? Did they put on new strut mounts?

I got some super f'd up noises driving on gravel from the steering colum it sounded like I assumed it was rack bushings, replaced those and I think it helped a lot, but I still get that front left rattle.

Haven't touched anything in the rack, just the outer tie rods. The shop verified the strut mount. Not sure which shocks they used, I didn't take a look. It seems to be worse when it's colder. I'm in Florida, so it varies from day to day. One day it's 80, then the next morning it's in the 30's.

I'll have to check that LCA bushing... looks easy enough to replace. I think that in the past the dealer replaced one or both of those, I'm not sure. I'd have to look at the history they printed out for me.

Good luck!

Edit: It actually looks like you need to press the bushing out of and in to its bracket, at least from the video I saw.

LCA is very common.

If you're near Longwood, check out Avi at ZTech. Excellent service for Nissan Z's and Lexus vehicles.

Tell him Don from Lakeland sent you.

Thanks! I'm in Tampa, but I think the shop I've got now is pretty good. They only do Lexus and Toyota. I'm going to see how much they charge when I bring it in.

Yup, my left front rattle goes away in the summer when its warm and when its in the negative temps for the first few minutes, during the winter it comes back. I wish someone could solve it once and for all but the posts ive seen just for front end shake the replacement parts list is MASSIVE from rotors and pads, to lca bushings, to tie rods, to tires, to bent rims. This rattle seems to be all the same parts list.

I've come to that conclusion as well. But the warm/cold aspect of it leads me to think it's a rubber component somewhere shrinking, then expanding. So it's probably a bushing somewhere.

Yup, I haven't seen much concern towards upper control arm bushings, and the noise seems to be high, atleast for me. Toyotas are notorious for strut mounts though too.

I had similar issue except mine was coming from the REAR driver's side. Sounded like a bag of chains being dropped when going over bumps.

In my situation, it WAS the aluminum anti-rattle bracket in the brake assembly. I was able to replicate it by tapping it with my finger or a screw driver! I took it out and reformed/bent it better to provide more rigidity while installed and locked into place.

Could the noise be coming from a tool, maybe an adjustable wrench (who really uses those on a car though? lol) that was dropped into the engine bay and never recovered? The bottom of the engine is very well sealed off from exposure to the road, which would prevent a tool from falling to the ground if accidentally dropped into the engine bay. I speak from experience in THAT situation also. I dropped a 10mm socket and found it about 3 years later when I took the bottom plastic cowling off. I'm talking about the plastic covering that you partially fold down the flap by removing 2 screws, when changing the oil filter.

Next time the car's up in the air, take your anger out on it and rap upwards on the plastic with your fist. Make sure to go around the entire perimeter of the cowling! I would also use some eye protection because you'll probably have some pebbles and rocks and sand rattle about and possibly fall down!

Hahaha, I actually suggested that. I'll check, but I don't think it's a loose tool.

It's always the 10mm....

I did that test to mine awhile back when I did steering rack bushings and the splash guard definitely flexes and rattles in that area I get the noise. I seem to remember driving it with the splash guard off and getting the same noise though. Lately my fix has been to turn the ML radio up...now the pass side speaker is rattling LOL. GRRRR.

I may do an oil change tomorrow so maybe I'll leave the guard off.

I replaced that speaker a couple months ago. I thought it needed to be refoamed, but when I pulled it out the foam was perfect. It looks like the voice coil was rubbing on one side of the inside of the pole (due to years of gravity) creating distortion.

When I had this front end metallic rattle/clinking, it was my exhaust pipes' heat shields and heat shield clamps. Very easy to check, no need to lift if you can shimmy underneath. I recommend removing the heat shield clamps and heat shields altogether. The dissimilar metals touching each other causes invisible Y-pipe leaks that cause the P0420 and P0430 "catalyst poor efficiency" codes. Add road salt to that equation and the galvanic corrosion will occur even faster. Nothing wrong with the catalyst, but the Y-pipe needs to be patched. However, if the rust is too bad, it can't be patched and you need a new Y-pipe, which comes with a new catalyst. Tell them not to bother reinstalling the heat shields.

Another possible source of the rattling noise is the shield in the picture at https://www.clublexus.com/forums/ls-...l#post10148457

If the sound is more of a clunk, then others here have reported lower control arm (LCA) bushings as the problem. The bushings can be pressed in and out instead of replacing the entire assembly, and only use OEM bushings since they are constructed to be installed in one direction only (note the orientation of the nipple). I haven't had either problem (yet?).

I refoamed my subwoofer several years ago, and my front left and front right speakers a few months ago, all with SimplySpeaker kits, all sounds brand new now. Some tears in the foam surround are very difficult to see, you have to poke and wiggle the foam to see the defective parts.