docmarioce

I have a 2011 LS 460 with 32+K miles and since its last service done about 6 months ago is making some weird thing. When I am stopped in a light and release the brakes the car makes like if the rear right tire was on top of a rock and it came down. Its a funny feeling. It does not do it all the time but when it does it does it 2-3 times in a row. Yesterday I took it for service to the Lexus dealer and a mechanic (supposedly the master mechanic) did a road test me driving and the car did not do the thing. He did not know what I was talking about when I explained it to him. I guess he though I was crazy. We, the ones who don't know much about mechanic, tend to think that there are loose bolts or screws inside but maybe you the ones that know about mechanic more can give me some inside. With my little information do you guys have an idea of what could be wrong with my beloved LS?

Thanks,

Mario

roadfrog

Sounds like a differential issue to me. I'd start there with a drain and refill of the diff. Next would be the brake caliper and pads/hardware.

Please let us know if you solve this issue.

Nospinzone

Or it could be a loose universal joint. Unfortunately you may just have to have it happen while the mechanic is in the car.

docmarioce

Thanks. I'll pass this info to the mechanic. Car is still in the dealer

roadfrog

There are no universal joints on the LS per se. We have giubo joints which are rubber. Normally when worn out, they will clunk when coming to a stop (as the transmission gears down).

Remember to let us know what transpires, as this information can be of great value for members here.

docmarioce

I picked up the car yesterday afternoon. The mechanic found that the arms of the front suspension were worn out and replaced the four of them. The car was making a stump noise when breaking in stops and is not doing it now. I drove it from the dealership to home only and did not feel the funny thing so it may have been that although is too soon to tell I'll drive it to the gym today and maybe further away and will update this thread with results. Thanks to all for your help

docmarioce

Just driving to the gym now. It did it again. While stopped in the light when I released the brake it did a clunck noise and a soft shake that lasted a second. I felt it in the rear right side. Probably will have to take it to the mechanic for another road test

docmarioce

Yesterday my car did the thing again. While stopped in a light after releasing the brake I felt as if the right rear tire was in a hole or entered a hole in the road and came out. There is no noise. I was looking through the passenger window when that happened and saw the car moving like a boat. I don't know what it is but the movement appears to be more pronounced now than before. Could it be related to the parking brake that gets activated and takes longer to releas one side more than the other? I recently took the car for service and I drove the car with the lexus mechanic as passenger and the problem did not appear and now is happening more. I guess I'll have to wait until the car completely stops and does not work. I am really concerned that it could be something major. Sorry to bother you guys with my problems but I know there are very smart and capable people in this forum.

Oliver Enterprises

Someone else on here had (what I remember to be) a similar experience, like you are describing. And went round and round with the dealer. Until finally one smart tech figured out there was air in the brake line for (seems like) the right rear brake. The line was bled, and the problem was "Gone With the ... Air."

That's from my memory. I'll see if I can search and find that thread.

GR6RR

LS430FL or something like that?

Rhambler

Well, the simplest test, assuming you are using the brake hold feature (which it sounds like you are), is to stop using it and see if the problem persists.

If it goes away then it would be narrowed down to your brakes and/or brake hold mechanism, which might not be releasing or getting stuck.

Nospinzone

Trust me, you are not bothering us. We love to dissect these problems. I don't remember the thread Oliver is referring to, but a brake line bleed is an easy procedure and can't hurt.

Besides, I didn't know our cars didn't have universal joints! (Thanks Chris/roadfrog)

docmarioce

Thank you that could be the source of the problem. Don't know if the mechanic would agree to do the bleed only with my argument or if they would like to feel it first..

Thanks again, Mario

docmarioce

Thank you. I'll try the air brake bleeding.

docmarioce

Thanks for your reply. I don't use the brake hold feature all the time but I have used it at times. When it happened I wan't using it. I activated it afterwards to see if continue to occur and apparently improved. I'll make some tests with the brake hold on and off. I'll also look into the brake air bleed as well.