Hi. I have a 1998 Lexus ES300. When I drive on the freeway at 60+ MPH for more than 10 minutes the car starts vibrating. When the car come to a stop, it start vibrating like crazy. The car vibrates a bit when in motion too, but it's not very noticeable. Here is a video of it happening:

http://www.youtube.com/watch?v=YAxOH...ature=youtu.be

When I turn off my car and turn on my car it doesn't vibrate, but the moment I start the car again, it vibrates. If I leave the car off for at least 10-15 minutes and then start it, it stops vibrating.

My guess is that it is the idle air control valve, but I'm not too sure. Any suggestions?

 

I had something similar before I cleaned my IACV, but it wasn't as violent. I even had misfires and a CEL come on. So yeah, go get a can of Carb Cleaner and spray it into the IACV. I also tried to get some gunk out of it, by dipping a piece of paper towel into the opening. It must have worked, because the problem went away.

 

I cleaned/replaced my IACV. Then I drove about 50 miles on the freeway and through the mountains. I came to a complete stop and the car didn't vibrate. At the next intersection, light suddenly turned red, so I put a sudden brake. Car still didn't vibrate. Then I stopped at a stop sign. No vibration. At the second stop sign, the car suddenly started vibrating (like before), but 1/2 as violent. I turned the car off for about 3-5 minutes and the vibration went away. Drove 50 miles back on the freeway and came to a stop (no sudden brakes this time) and the car didn't vibrate at all. Do you think it's a problem with my brake pads?

Still better than before, where my car vibrated 10-15 minutes into driving on the freeway and during the drive no matter what.

 

Here are 2 free things you can try:

Based on your video and descriptions, a vacuum leak is a real possibility. Check carefully the large snorkel hoses in back of the air filter. They are notorious for developing a crack which opens up and then re-closes under certain engine loads. It's best to remove them and visually them.

Also check your engine/transmission mounts.

Phil

 

Ended up taking it to a mechanic while the car was vibrating. Mechanic said the problem was with the exhaust gas recirculation valve. Got the problem fixed. hopefully the car won't vibrate anymore