2003 Honda Civic. Any speed between 30 and 50, car suddenly starts pronounced steering wheel shimmy, too intense to ignore. You can park, start up again and it’s gone.
That’s a fairly unclear post so you’ll have to give a better description if you want suggestions. You said if you stop the car, shut it down, and start it back up the shimmy is gone. But, you said the shimmy is only there between 30-50. So presumably its “gone” anytime you’re under 30 - I think being parked counts as under 30 so its no surprise that its gone when you’re not moving.
So maybe you’re saying this is an intermittent problem? Sometimes you go 30-50 and there is no problem? But sometimes there is? And when there is, if you stop, turn the car off & then back on you can now do 30-50 for a while without any shimmy? But then it might start doing this again every time you’re between 30 and 50 until you shut the car off again?