biggajigga

Hopefully somebody here can help me solve this problem. Since the day I purchased the car, the whole family has loved it -- it is absolutely the best car we've ever owned. We've described the ride as something similar to driving on water, with everything feeling buttery smooth. There's only a hint of bumps in the road and traffic noise -- but only enough to let you know it's there without giving it a second thought. That was the story from everyone who's been in the car and who's driven the car during the first 5,900 mi.

An oil change and tire rotation at Lexus was done at 5,800 mi. Along with the oil change though, the car wash person backed the car up and caused a dent in the plastic bumper. It didn't appear serious because there were no scratches at all and the bumper appeared to stay on the fairly well though.

Aside from that, about 100 mi later or a few days later while it was raining here in San Diego (just last week) the car started to sound noisy and felt jarringly bumpy over certain bumps and potholes. It's noisier over any kind of pavement that is not perfectly smooth and the car does not seem to absorb bumps well anymore, the car still stay controlled and stable except the floor feels like it vibrates and the chairs seem to vibrate also as a result of the road. Two people have driven the car on separate occassions without speaking to each other before hand about the problem and noticed that the car seemed noisier and bumpier. I want to blame the Dunlop tires or computer problems with the adaptive air suspension, but I'm not sure.

The other observation I've made is that switching between Sport and Comfort damper settings makes only a small bit of difference, Sport mode seems to control body roll more but the steering and the ride quality feels practically the same (Sport actually seems to lessen the vibration somewhat). Before I noticed the bumpy ride, switching between Sport and Comfort did what I expected it to do (Sport: less body roll and quicker steering with a slightly stiffer ride but more controlled; Comfort: smoother over bumps and less direct steering) and easy for me to distinguish the differences between the two.

So what do you guys think happened? What can I do about it? I fear that if I take it to Lexus to check it out, they can easily tell me that it is just my imagination and everything in the car is fine.

Information about the car:
2004 LS430 with 6,100mi since Oct. 2004
Ultra Luxury Edition with the air suspension
17" Chrome wheels with original Dunlop SP Sport 5000 TIres
I have only completed 1 service that included oil change and tire rotation.

Thanks for all of your help. Hopefully I'll start to love driving the car again, but right now, it gives me a headache driving it and wondering what went wrong with my previously perfect car.

DaveGS4

iTrader: (2)

Regardless of the potential for the dealer not recognizing the issue... definitely take it in and get the problem logged and checked out. If it gets worse over time, you'll start to have a history of when it went bad (under warranty).

Smoothride

I second Dave's idea, but the first thing I would check is the air pressure in the tires, I can tell a 2 pound difference. I usually run about 32-34 lbs and it's a nice compromise b/t comfort and handleing; any more and it's harsh, any less and it 'wallows' in the corners, it's possible that you had them underflated, or now they are overinflated. Go and get a good digital air guage (not the cheap stick type) and keep the air pressure up to date. Also, when it warms up, the tire pressure goes up a pound for every 10 degrees, but when it gets cold, the pressure lowers BUT the shocks and tires get cold and stiff.

blacksc400

iTrader: (4)

do you have the regular model or the UL one??? I hope your air suspension did not get mess up because that will cost you a fortune..

DeniskaGS4

its a brand new car.. its not going to cost anything to fix

DDLexus

Tire pressure is a good check. Also, I'd check the rims. I've had times that my rims accumulated brake dust and other dirt. After giving them a good cleaning, the car felt smooth. The part i'm referring to is inside of the rim, not the part that you see with the tire mounted.

Another possible issue would be that the same people to dented your bumper might have ran into a curb. I'd take the tires off and have them rebalanced. If they are fine, you might have more evasive problems (electrical), but I doubt it.

Smoothride

Hey biggajigga,

I reread your post, I'd say to have them rebalance the tires, I missed the vibration part the first time. Maybe they moved an unbalanced tire to a different corner of he car where it's more noticeable.