I recently bought a 2000 LS400 and noticed that the car vibrates at around 90 miles per hour is there any way to fix this?

 

Yo, Player...

You hold the lock and the key...

The short answer is by not driving 90 MPH

 

Thats the flow of traffic nowadays

 

In every city I've been even though the limit is 55 on the inner-city highways, the regular flow of traffic is 70-80mph in all lanes. If you're doing the speed limit you're an anomaly.

Hell, there even are areas where the speed limit is 75 or 80 and everyone goes 85 or 90.

This could be as simple as wheel balance to motor mounts to suspension. You'll need to give more information and do more testing to determine.

 

Have to check the suspension for worn bushings which by now are pretty numerous. May be engine, tranny, differential mounts as well as drive shaft. Often this is a tire balance issue. Rotate the tires to see if it changes the vibration form front to back , etc.

 

my recommendation to most vibe issues:

 

This is something you will need to inspect and see first off is there is any play in the steering tie rods, rack itself, ball joints, control arm bushings, subframe/engine bushings if you have any, engine damper.

Also make totally sure the the wheels and tires are actually properly balanced and the wheel hubs are not worn or have play since those will get worse and worse the faster your go. Steering tie rod issues will actually have a speed range where they are at their worst because if you go faster the increased toe load will prevent the worn parts from moving back and forth and the vibration will stop. Wheel hubs just get worse as do tires the faster you go, driveshafts have fixed rpm ranges that problems show up at and engine mounts/damper is also RPM dependent and you can isolate those by shifting to neutral at the problem vehicle speed and observing if the vibration immediately stops when you do.

Less likely but a hanging brake caliper may drag enough to warp out a rotor at higher speeds and have enough contact to shake but usually if they do this a full lockup of that wheel is not far off.

Suspension bushings and strut mounts can be checked by adding a go pro camera to the underside to observe the arm in question while you drive it at the problem speed if it proves too hard to figure out when the car is not moving. I've only had to do that a few times to isolate issues in cars that were giving me a hell of a time finding the issue on. Worst was a 2008 Camry V6 that ended up being the rear subframe front bushing only causing the vibration when the arm went over rough patches at 0-7mpg and 65-70 mph and compressed that particular one enough to contact the body with the rear subframe and cause the noise.

 

I I got new wheels and got them balanced, no more vibration👍🏾