TooCoolSC

Hi, I just joined because I just bought a 2002 SC with 68,000 miles. The car has non-run flat tires (Michelin Pilot XGT - 245/40 ZR 18 93W M+S), and everything I read prior to buying the car said the non-run flats made the ride noticeably better and quieter. One review said the tires transformed the ride of the car into exactly what you would expect from a high-priced Lexus vehicle.

I'm sad to say, though, that even with these non-run-flat tires, I'm very disappointed in the car. Every little bump in the road shakes the car and is loud. Is the suspension of the car a known problem?

It's as if the car does not absorb anything at all. And I'm not talking big potholes, I'm talking just any bump and crevice in the road. In addition, the tires seem to have a loud and very bothersome "whirring" noise when going 40+ mph or more.

I called my favorite tire store and the guy I talked to basically said there was nothing that could be done. He said it's just the way the car is. He said going to a V or H rated tire might help some, but probably not that much. He said the only thing that would help would be to possibly go to a smaller wheel (17 in.) which would increase the sidewall of the tire to give it a more comfortable ride. He said putting bigger wheels on it (19, 20 in.) would only make the problem worse. I would gladly give up some performance for comfort. I'm not going to be racing the car around. I just want it to drive smoothly and nicely.

I was just wondering if the rest of you have this same problem and if there's anything to be done about the ride of the car. It's just unbelievable to me that Lexus would make a car that is loud and bangs and shakes every time it hits an imperfection in the road.

Is there anything I can do to have a normal driving car? I know this is a convertible sports car, but I wouldn't think it would make THIS much difference.

BTW, the tires that are on the car are not that old and the Lexus dealer that checked the car out prior to me buying it said the tires/wheels didn't show any major problem. So this shouldn't be a tire problem. The car is in good shape and has never been hit, etc.

Any help anyone can offer would be appreciated. The ride of the car is really interfering with my enjoyment of it and I'm already questioning my purchase. I'm also embarrassed to have anyone ride in the car because it's so loud. That's the last thing I expected when I bought the car.

Thanks!

SEVY B

Changing the bushings will help. The bushings are a known problem. You may also consider changing the shocks as well. They're most probably in need of a change. My mechanic told me that the SC isn't a typical smooth Lexus ride in comparision to a LS or ES.

da-bizket

Ride: Check the tire pressure. You should be able to bring it down to lower level and still be within your tire's specifications. This can help the ride quite a bit.

Noise: Tires can make a difference and a good shop can tell you if your tires are more performance oriented or ride and comfort. I am not sure what your tires are rated.

I came from a LS400 into my SC and the noise drove me nuts at first too. As I started to drive around more I noticed certain road surfaces created a lot more noise than others. Then I compared the SC to other cars I drove in. It was somewhere in the lower to middle area as far as noise goes. It's obviously only a problem with the top up. I eventually got used to the road noise and don't even notice it anymore.

robsvdp

Sounds like something is not right with the car or tires -- i came out of a Jaguar Vanden Plas (super smooth) , and even with runflats I have never hated the ride. Never had shakes/bumps, etc as you describe. I now have non-run flats and it's even better. It doesn't ride "like a lexus" (used to have an LS, and it felt like it floated on air), but way smoother than my friend's 911. Long way of saying I agree you should look at bushings and shocks.

johnnyreno

that car has been wrecked before you better check the history

jimmer!

while switching to conventional tires, I went with nitrogen in the tires.
my '04 430 now has a totally acceptable sports ride, not the previous harsh, brittle jaw jarring thing.

I'd recommend switching to nitrogen...

quadocox

My ride is hard like the OP mentioned but I simply accepted it as how the car was made.

It doesn't bother me.

rclab1

Jimmer: how does Nitrogen affect smooth-(ness) ride factor????

TooCooLSC: get some Continental ContiPRO's HR "GrandTouring" tires
245/40/18 OEM size Non_Run Flats. you will be amazed how
smooth the SC430 rides after these tires..... TireRack.com

These ContiPro Tires are HR rated, not high Performance, but the trade off is a night/day difference. Very quiet ride and very smooth! I've had them for two summers now and I'm never disappointed.

quadocox

Anyone know if springs will offer a softer ride

TXFM

The original 2002 SC430's did have a bushing problem in the rear suspension ( https://www.clublexus.com/forums/sc-...sion-prob.html ). There was even a Tech Service Bulletin on this problem.

I think the first thing you need to do is to see if you can check with the dealer who has performed the service on this car to see if the rear bushing upgrade was ever performed. It does make a difference.

TXFM

Here's the TSB info (thanks pearlpower):
TSB #0489, Ref # RS-01-001R
Re and Re Rear Sub-Frame, Replace Bushings

coach1

To answer the question......Yes.

My SC w/run-flat's, rode a bit like a buck-board. It was fine on a smooth black top highways. We have some stretches of interstate that are a little ruff and some cement that made for a ruff/noisy ride. After swapping those out for Michelin Pilot A/S the car floated over those conditions as quietly and smoothly as any full size luxury sedan.

If you are still experiencing noise and vibration, I would check out 1. the age of the tires 2. balance 3. tire pressure 4. bent rims 5. history for accident, suspension damage. I had a 500SL with Michelin tires that was not riding as I thought it should. Tires looked good, but it turned out, over time, the tires got hard or developed flat spots from sitting in the garage. Installed a new set of tires, made sure the shop did a good job of balancing..........improved the ride 200%.

"In my experience"......There is no reason that these cars can not be equipped with the right set of tires and adjusted to ride as smooth and quiet as anything on the road. Look Luck

rcpeters

My SC430 has non-run flats; Nankook Ventus V4ES 245/40/ZR18 tires which are OEM size. The tire pressure is checked by Easy Lube and I assume it is within the specified range, I have not checked my tire pressure though; I guess I should let some air out and verify that the tire pressure sensors work.

With the radio off and top up, the only sound is the rumble of the exhaust. The steering is tight and I can notice a slight road feel typical of a sports car. Occasionally, when going over a bump, I can hear some creaks from the top; not bothersome though.

Our LS430 is smoother and quieter, but the SC430 is just fine. I have test driven SC430's with run-flat tires and the ride was terrible.

Maybe you should visit a dealer and find a SC430 with non-run flats and go for a test drive. That will demonstrate what the ride should be like. This will help you determine if there is something wrong with your car. Then follow the suggestions of other members to determine what is wrong with your car.

TooCoolSC

I'm thinking this is the problem. I have the entire vehicle service report and I don't see anything about the bushings ever being replaced. And from the link you provided, my VIN# is much lower than the number after the corrections were enacted.

Is the Tech Service Bulletin number you provided something I can give to Lexus service and they can still look it up? Is it something that should still be covered by them.....like a recall, or do you think I'm going to get stuck with the bill?

Thanks so much for all the help on this from everyone. I'm thinking a combination of bearings/shocks, new rims and some good quality non-run flat tires should solve the problem.

Is there any reason not to go with an H rated tire? I used to have some H rated Yokohamas on an Acura Legend coupe and they were very, very smooth. Lasted many miles, too. Of course, they were only 15" tires, not 18. I'm really finding that these low profile tires are a pain. They are expensive, they don't last as long, and they provide a lower quality ride. One has to wonder why the whole industry has gone to the bigger rims/tires. I don't think the look of them justifies the additional costs/problems.

flyguyskt

well i think the sc 430 rides friggin super gr8...even with the run flats on it. this is totally a perspective thing.

after driving the wheels off of a lotus elise with sportpack for the past 2 years and then buying a yaris hatch for daily driver that i dropped with coilovers and threw on some falken azenis 512....

umm ya the sc 430 is like sittin on the sofa baby! yaaaa