Buying a 01 voyager but it vibrates

Hi all, I just tested a 01 voyage that works well except for one problem. when you accelerate you get a vibration on the van. It stops when the van levels out and starts again if you increase the speed e.g if you accelerate to 20mph then it vibrates till 20mph but stops if you stay at that speed. then if you accelerate to 30mph it vibrates till you level out at 30mph. It feels like something is loose. When the van is in neutral and you rev the engine it there is no vibration. Has anyone ever experienced this. I really like the van and want to buy it but this is stoping me from buying it.
Thanks

My opinion, unless you're getting some phenominal deal, I'd walk away. There are so many of these vans out there, just keep looking. Anytime I've brought a vehicle to a shop for a vibration, it turns into an ordeal. Or, if you are buying from a dealer, you could make them put it in the contract that they will fix it. I just can't see shelling out the money for a vehicle that you know has a problem if you can get a comparable vehicle for the same price without a problem.

I'm getting the car for $5000 and it is in mint condition with 78k miles. Do you think it's a good deal?

I'm getting the car for $5000 and it is in mint condition with 78k miles. Do you think it's a good deal?

If anyone has ever done a service on the tranny and used anything but the mopar spec tranny fluid recommended in the owners manual it will cause a vibration just exactly like the one you describe.

Actually I purchased the van and I took it to a mechanic. Found out that it was the engine mount. I changed the front one which I hear is always a problem with these vans but seems that another one is bad. It looks like the back one. I'll change it and see how it works out. Good to know about the tranny though.