Chevrolet Repair: car noise, car noise, step on the gas

Question
I have a 99 venture with a lot of miles on it.  Very recently when you excelerate there is a loud clunking noise.  It appears to be coming in the center rear under the hood.  

Answer
Hi Leigh,

Sounds like a motor mount.  Could be something else, but most likely it is the motor mount.  

Have someone stand outside the van, with the hood up.  Then, start the van.  Put your foot on the brake HARD.  Then put the car in reverse and step on the gas lightly.  See if the motor seems to move excessively.  Then do the same for forward.  If you hear clunking as you do this, it is the mount.  If you see the motor move excessively, it is probably the mount.  

When I say 'move excessively', I mean the motor will move some when you do this.  If it seems as if it is rolling front and back as you tap the gas, a lot, then it is the mount.  

C J S