BradTank

One way you can sometimes track down the noise is by getting a heat gun, and heating up different rubber areas and then taking it for a spin to see if the problem is gone, eliminating areas one by one. (this is assuming colder weather makes the noise come out)

A shop told me the creaking was my rear strut mounts, but I thought they were wrong, so I heated up my rear trailing arm bushings, and sure enough, the noise went away. A $40 fix instead of a $1,200 fix.

I strongly suggest you start though by replacing the rear control arm bushing/knuckle carrier and lube it with something like Sil-Glyde (silcone grease). The part number for the bushing is ADUS part #577


if you want to to be cheap, just remove the factory bushing and put some silicone grease on it to quiet it down. I can almost guarantee you EVERY single ES300 after this many years will have issues.

RXGS

iTrader: (2)

This may sound stupid but today it was raining extremely hard and while driving, the sound wasn't there anymore. Then it dried up and the sound came back?

schmoozer

I believe this is the same for myself as well. Hasn't rained in a long time so I can' t be sure.

If it's dry and cold...oh lawwwd it's noisy.

Power6

If rain makes it go away, I'd guess it is one of the rubber bushings in the suspension squeaking. When wet it has just enough lubrication to quiet it down. Might be tough to figure out which one, you could catch it on a dry day, spray some lube one by one on each rear bushing and take a ride to narrow it down. That might be easier than the heat method.

BradTank I assume it is the rearward trailing arm bushing that gave you trouble, figures it is the one in the knuckle probably needs to be pressed out. Whole trailing arms with the forward bushing are so cheap for the Camry chassis. Then again if the "forks" of the trailing arm are what is rubbing on the bushing in the carrier, maybe a little lube is an easy solution there.

I wouldn't recommend a poly bushing replacement, poly needs to be greased regularly because it doesn't work like a bonded rubber bushing, leave the poly stuff to the race cars.

BradTank

The problem is, Lexus doesn't sell this individual bushing (you have to buy a whole new knuckle) and I can't find a supplier that sells a rubber one, so if you want to replace just the bushing, you're pretty much forced to buy a poly one.

I honestly noticed no difference in the ride and it has stayed quiet.

If you find a source that sells a rubber replacement, that would be a great find.