VERY LOUD acceleration, sounds like a semi!

Title more or less sums it up.......when I have to accelerate hard (such as on the highway), my 97 sounds like a semi. Its loud enough to make conversation hard to hear in the car.......The sound continues until I stop accelerating.
A search led me to check the motor mounts, they are fine. Any other thoughts?

U-joints? Check em out. You dont even need to jack it up. Just a couple screws and youll know right away if one is bad once you drop the drive shaft.

Oh, but you might want to have a couple of new ones before you take the old ones out cause the bad one that I had fell apart instantly.

Might also be the fan clutch engaging prematurely. When it happened to me it really did make the engine sound alot louder.

U joints are fine, checked them this weekend.
Also have a pretty loud take off thump, not sure if it might be related or not.

Tranny?
Does the sound only happen when downshifting or otherwise using the passing gear?

Tranny?
Does the sound only happen when downshifting or otherwise using the passing gear?


The loud acceleration is pretty much anytime I accelerate. The thump is when Im taking off from a complete stop.

Check your motor mounts. With plenty of room in front and behind the car, raise the hood, set your parking brake, start the motor, put the trans in Drive, applying the brakes gradually press down the accelerator pedal while looking through the gap between the cowl and bottom edge of the hood where you can observe the engine.
Does the engine rise vertically on the drivers side more than 1/4 inch? If so, the drivers side motor mount is broken.
Release the accelerator pedal, put the trans in reverse then gradually press the accelerator pedal again with the brake still applied while looking at the passenger side of the motor.
Does the passenger side of the motor rise vertically greater than 1/4" too? That would indicate a bad passenger side motor mount.