spence288

iTrader: (1)

Hi All,
Just got my 2002 SC430 and love it !!!
Have been reading the forums and they have been a great help. Thanks to all of you.

I have noticed that my car has a pronounced vibration in 3500-3000 rpm range. It is at its worst when decellerating through that range. It is also preceptable at about 1500 rpms. You can definitely feel it through the shirter and on the floor.

It is not associated with the gear or speed...only rpm. This seems to rule out tires.

Any ideas??? Any one else experience this? Is it the nature of the beast?

thanks

arien_one2

How many miles does your car have? Is it still under warranty?

rominl

iTrader: (4)

if it's at rpm not speed, then it's hard to see what's going on, maybe some of the engine mounts and stuff? dunno.

but either way you should have warranty still, maybe you can just bring it in?

spence288

iTrader: (1)

25K miles so still under warranty.
just wondering if it was "normal". based on the comments, I am getting the idea that its not.
thx

antigeek

No research on my part yet, but I drove about 100 miles to & from Tyler this past Thanksgiving, and I noticed quite a bit of vibration at speed. I thought it was the tires, but I'll look into it more and let you know if I have the same problem.

Mine is an '02 model (10/01 manuf. date, acquired 11/23/01) with 32k miles on it.

spence288

iTrader: (1)

on mine I don't see it EXCEPT when passing from about 3800 down to 3200. smooth as silk just about everywhere else. thanks for checking. I think my build date was near april 02

kasendorf

Have had a similar problem and it turned out to be a bent wheel on a front tire. Moved the tire to the rear and this help until I could replace the wheel.

spence288

iTrader: (1)

I would have thought that a bent rim would have been tied to the speed rather than the rpm. was the vibration you experienced consistent only on rpm???
thx

antigeek

It turns out that my vibration is wheel-related.
When I get up to 65MPH+, it gets pretty ugly.
A good test: a 20oz. bottle of soda shows it well.

I replaced my RFs with Michelin Pilot Sport A/S's from Discount Tire.
I smacked one of those 4" road t*tties (what else can I call them?) and blew out the right rear with a minor impression in the outer rim. I thought that was the cause.

I drove to Austin last weekend, and the usual excellent cruise in the SC turned into an irritating light massage trip. Fortunately (?) I got a flat in the left rear. I took it to a Firestone (hey, they were open on Sunday!) and had it patched. The guy who worked on it said he found weights not concentrated in a single area. He removed them, and rebalanced the wheel. MUCH better.

I'm probably going to take the SC back to Discount Tire & have them rebalance all the wheels.
I had them rotated about 2,000 miles ago, so they shouldn't have exhibited this problem.

rominl

iTrader: (4)

umm in that case maybe you should really check to see if any other wheels are bent or something?

antigeek

Agreed. Without run-flats, any low pressure (e.g. < 35PSI) could allow a pothole to do some damage.
I'll check on a bent wheel, but I'll start wih the rebalance. Any wheel with a need for > 1 oz of weight indicates a problem -- those kind of differences can't be addressed well with weights (from what my trusted tire guy tells me).

The surprise to me was that the wheel opposite the one I hit, when rebalanced, reduced the vibration I had significantly.

I suppose I learned a few lessons:
- I suck at owning low-profile tires (I try to be responsible & park close to the curb)
(Please, no curb feeler ideas. If I could invent an invisible laser-based system, I'd do it.)
- monitor tire pressure more often
- check the balancing of my tires

rominl

iTrader: (4)

yeah i agree that's the problem with low profile tires. i have 20s on my gs4 and i always have to keep checking the pressure regularly, and make sure everything is good. otherwise it can put on unnecessary wear on the tires too