Rattling only when accelerating

Wheel bearing . If gets louder as acceleration increases !

1 Collapsed wheel bearings
2 Lose wheel nuts

Jack up front drivers side wheel and grab the top and bottom of tire, give it a good firm wriggle and see if you can detect any movement.

Check the droplinks for the anti roll bar... some are like ball joints, and they can seize, which causes the symptoms you are getting.

Just an idea:
Try to check your tires inflation and size, They should have
the same tire witdth ans same inflation.

Could be catalytic con.in side.

Is it a "tinny" sound? If so its probably a heat shield.

is the spare tire hanging under there? i had my spare come loose and was banging around under there, maybe a shock has gone bad!

You are probably hearing the front stabilizer links going out. they are ball jointed on both ends and run to the struts. When they start to go, they thump a lot over small holes and cracks in the pavement.
Also the lower control arm bushings may be at fault, especially if you have had a fender bender. I would start with the stabilizer links (it's a do-it-yourself project) and then go from there.
A good way to check the links is to have someone rock the truck side to side while you hold the link (reach around the back of the tire and grab it) if you feel play in it or it moves too easily or is disconnected or broken, you need to replace it.

possibly the bearings in the water pump,but that should have been replaced when the timing belt was done,because of the work involved

no it would not be the timing belt making a rattling noise it couldn possible be you heat shield around your break rotor it could be someting having to do with ur suspenion like a spring maybe what kind of rattling noise? or a regular heat shield but loose in that particular area