When driving noise over 30 mph - 1999 Kia Sephia

it could be center bearing, if its going bad it can also cause a vibration, make sure you have sufficient fluid in the diff as well, you can also get a noise and vibration from collapsed motor or trans mounts

Noises are decieving. Cud be steering system or wheels or suspension. If ball joint fails car cud flip ovr.hav pro testdrive it. Seek a gudguy at surecritic.com

Go with a completely damaged & blocked exhaust converter

Air In --Air Out Yours doesn't go out & the trans gets confused
& can't use the shift strategy it was born with

That is the 30 mph or a gas filter really clogged,not real likely

What is with the noises?

Turning & just sitting still?

What was the trans shop diagnoses,was it test driven
& did you go alone,have to do that

Your car --so your part of the solution,be proactive

you would have to find out where the speedomator wire/cable
connects
heres some idea

there is a gear at the end of a speedomator cable

try this 1st hit me back if this dosent work

If it only did it once then it was a road problem most likely and not the car.

Probably a broken seal somewhere around the edge of the windshield

I would look at the half shafts or cv axles.

find the oil preassure switch and install a tempeary mechanical guage and eye ball the oil preassure it sounds like low oil preassure

noise can be many things like tires .front axle bearings final drive.torque converter.