Severe shaking only when accelerating

[sedona03]

The dealer's service dept. can't figure out what's wrong because this doesn't happen during their test.

Our 2003 Sedona van (with about 97,000 miles on it) is usually fine. However, after about 30 minutes of driving at highway speeds, the van starts shaking severely. If you let up on the gas pedal and coast, the shaking stops. If you try to maintain speed or accelerate, the whole van shakes terribly. If you hit a bump in the road, the shaking stops for a second, then resumes. It does this for about 15 minutes, then the shaking suddenly stops and all is fine again. It's gradually getting worse and happening more often and at slower speeds. They claim it's safe to drive.

I'm the original owner, so the 100K mile powertrain warranty is still in effect. Over time, the dealer has replaced 3 axels, some lug bolts, and a motor mount, and still can't determine what's wrong. It's not the tires because the shaking would be all the time, not just when accelerating.

Any of this sound familiar to anyone? Any suggestions? Thanks.
(This site is a great resource. Keep up the good work.)

[ron1004]

It sure sounds like a drive shaft problem, or maybe the center bearing that's found on the one shaft.

Why not take it to a drive train shop and see what their opinion is, and based on that take it back to Kia for repair.

[jasperwt]

I wonder if what you are feeling is transmission shudder? When my 02 (130,000 miles) goes into lockup at lower speeds, I get a constant shudder under light accelleration. Fourth gear also shudders when engaging. Rebuilt trans are cheap from Kia.

[kris_lpgcars]

it soud more like 60% of them like clutch problem, when it gets hot it starts not transfering 100% of power under the load

[woodchuck]

Is the transmission going in overdrive. I had them do the shudder thing when you're just trying to maintain a speed but when you accelerate or let off it stops. You can unplug the overdrive on transmission or rebuild. I know this doesn't fit all your symptoms. Does it affect it when you turn the steering wheel.(steering damper)

[davchaz]

I've got the same problem with my '03. Love to know what you find out!

DAve