Dear Colleagues,

My 1998 Seville STS with around 71K miles will begin vibrating at around 60-70 MPH. If I accelerate past that speed range, the vibration will die down, and if I remain under 55, I don't experience that vibration. I can feal it in the gas pedal, and I look over and see the passenger seat head rest vibrating. Does anyone have suggestions as to the problem?

Most Gratefully,
Alan

 

My guess is that one of your tires is unbalanced, therefore creating the vibration at certain speeds.

 

Thank you! That would certainly be an inexpensive fix, though I recall this problem coming up on the Forum a while back and a member suggesting some sort of filter as the culprit. Does anybody else recall such to be the case?

Gratefully,
Alan

 

Hello,

have you fixed the Problem, I have the same Problem with my 98 STS.
But the Wheels and Tires are OK, pherhaps it is Vibration from the Engine (Crank Shaft Balancer)
Any Ideas?

Gretings from Austria
Marco

 

NO I No im afraid, it will probably never be solved, all our early model sevilles will go on like this. There was another posting about this about a year ago. I know exactly what your talking about they all do it. Im preety sure its the way the rims are constructed. because when not balanced its killer in car, when balanced properly i must say properly meaning on a correctly calibrated machine, the vibration shimmy is almost completly gone! but still there. so that is y i know its the rims. Had my car 4 years and tried ton of balancing procedures, differnt speeds on same roads,different roads, for one mile 10 miles etc..It wil lawys be there. It would confirm if someone puts afttermakert wheels and and the problem disappears....Even some members went as far as changing wheels hubs,bearigs, whole suspension setup to try and narrow these out.

 

mine comes in about 67-77 mph...

 

OK, thanks for the reply, now there are Winter Tires on Factory Rims on my Car, I´ll try next Year on Summer with new Rims and Tires.

Marco

 

My 98 sls starts the same about 65 to 72. It hasn't always done it. Same tires and rims. But I know i have a bad motor mount maybe it is the problem. Also I have some kind of knock on the front right side of my car when I hit small and big bumps. Can that be the motor mount on that side or front end parts. It sounds like it is coming from up top around top of the shock area but you know how sound travels. It's a real distinctive noise like you would be able to see the problem easy, but I've looked at shock and motor mount and front end and it's not obvious to me. Any ideas how and what to check. My guess from the sound inside the car was maybe the shock was loose at top adjustment, but don't think it is.