gtg302s

I have a 99 ES300 that I am having an interesting problem with that I haven't experienced with any other vehicle that I've had. When I get up to highway speeds, sometimes the car begins to shake. It feels like the shaking is coming from the front end of the car. This does not happen every time I am on the highway, but if I go more than 20 miles or so, it seems to happen most times. It begins as a subtle shake and then gets more violent. If I don't stop the car and continue driving, the shaking continues and gets worse. As soon as I touch the brakes, it gets much worse until the car comes to a stop (the wheel jerks from side to side). After stopping, it seems to be much better until I get on the highway and it eventually begins again. There seem to be no symptoms of the problem when I am not driving on the highway. The tires are in good shape (pretty new and balanced) and I recently had an alignment done. When I got the car last year, I replaced the knock sensors. I was thinking that maybe it was the sensors again, but I do not have a check engine light on. I put after-market rotors on the car prior to the issue and my mechanic said they still look OK. I thought a stuck caliper could have been the cause of the issue b/c the drivers side front brake pad was wearing much quicker than the passenger side. This did not fix the problem. What else should I look at? Has anyone else experienced this issue? Thank you for your help!

hzt30

Rotate the front tires to the back and see if problem changes.

Hayk

iTrader: (1)

Your condition sounds extremely dangerous. Have a mechanic look at all your suspension joints (tie rod ends, ball joints, LCA bushings). It has to be professionally diagnosed.

Tac1sc

Try rotating your tires from L front to R rear then vice versa. If it gets any better but doesnt go away have your tires rebalanced if its still shaking, have the suspension cheked. If your rotors are stuck then youll smell it or if its rotor issue it will shake even on low speed but only when you apply the brakes.

hypervish

+1. This doesn't sound safe. I would get it looked at ASAP.

gtg302s

Thank you everyone for your responses. The problem seems to be resolved now. Here is what we did:

1. Had mechanic check suspension parts. Everything looked OK. This made them want to then look at tire balancing and rotors.
2. Rotated/Balanced the tires
3. Turned the rotors

The car is now driving well. I must have been wrong about the tires/rotors prior to taking the vehicle in. Thank you all very much for helping me resolve this issue!

285exp

I couldn't tell based on this whether you had replaced the suspect brake caliper or just replaced the rotors. If you don't replace the caliper, then this is going to happen again, trust me.