wvuguy

My 99 RX300 has recently making a 'whap whap whap' sound when turning right. It seems to be coming from rear driver side. It sounds like rubber grinding against some thing. Sound is definately not metalic. The frequency of 'whap whap whap' seems to increase and decrease with speed. I took a look at suspension components and nothing seems loose or leaking. Boots on CV joints seem intact. It seemed to have started as soon as the temperature outside dropped below 50 degrees. Not sure if sound has anything to do with temperature. Any ideas on this one ? Thanks.

Lexmex

Well things do contract under cooler temperatures.

The rubber supports under the spring on the rear shocks is a possibility, but also consider these bolts here and see if they are tight.

wvuguy

Lexmex,
Rubber below the springs looks fine. Can you please tell me which bolts are these? I double checked the suspension but nothing seems loose. Thanks.

artbuc

I don't think you can tell if the rubber isolator is ok by looking at it. Mine had worn away in the center allowing metal to metal contact but the part you see when the strut spring is assembled looked good.

Lexmex

There are actually a whole bunch of bolts that can get a little loose. This is the area, and I have circled all I know in yellow, but any bolts around this area, take a good look at. You may to shake the areas where the bolts/nuts/screws are to see if there is any play, but I do know the one above caused some knocking noise that drove me nuts until I checked each bolt and found the culprit.

wvuguy

I did check the bolts and nothing seems loose. Today the temperature went over 70 degress and guess what? No more noise. Not sure this little change in temperature can really expand/conract metal much. I am thinking its some piece of rubber some where in the suspension thats wearing out. It could also be the tire. I will swap the tire and see if the noise is still there.

Lexmex

Take a look around the shock area for any rubber pieces of any kind. Could also be an issue with the shock mount back there.

wvuguy

The noise disappeared for a month and now its back again and seems to be louder. Frequency seems to increase with speed but the noise disappears when driving over 30 m/h. The noise come only when I let go the gas. If I press the gas a little it disappears. Seems to be coming from rear left tire. I jacked up the car and tried to spin the rear wheel but it does not spin freely even in neutral. It spins a little but then I hear a click which seems to come from the transfer case and gets hard to spin. I am wondering if its the brakes causing the noise. I have to make a 500 mile trip on Saturday and not sure if I can find a mechanic before that. Doesn't seem to have problem driving on highway though.

Lexmex

Again, the only real way is to have a remote observer and try to pinpoint the noise area.

wvuguy

I took it to a local shop and they said it needs a new rear left wheel bearing. Also said the rear left rotor is warped which could also be making the noise. One would think that bearing would making a constant humming noise and not 'warp warp warp' noise which disappears at high speeds.

JAB

Could be a frozen caliper slider or a broken parking brake, among many other possibilities.

wvuguy

I went on a 500 mile trip and now the noise is gone. I did check caliper slider but did not find anything wrong.

wvuguy

Ok the sound is back and very loud this time. When I hit gas it makes a loud griding noise. When I let off the gas it turns into a squeel. I am gonna get the rear right bearing replaced and see if it fixes the problem.

wvuguy

The problem is finaly solved. I took the car to a locally owned shop. The guy over there drove the car and said it does not sound like bearing. He took the axle apart and found a gear broken. Replaced the gear and no more noise! He charged $60 only. Lexus dealership has flagged the car when I was buying it and had recommended changing rear right bearing, axle and speed sensor for a total of $2700!