Purchased a 2000 F150 (over 200,000 miles) from a company fleet. The truck is not driven on a daily basis, only when needed to haul something to land field. One morning I had to drive the truck. When I pulled out of the driveway and began acceleration the truck began to shake violently. After some experimentation I came to the following conclusion. The vehicle starts to shake when a speed of 45 mph reached. If I try to hold the speed between 45-55 mph the shaking continues. If I let off of the accelerator, the shaking stops, if I accelerate thru 45, the shaking stops. The shaking is not from wheels, rotors, axle etc. The check engine lite also came on during this time. When the shaking starts, if I attempt to accelerate, the truck looses power briefly then picks up. I didn’t pay alot for the truck and really don’t know how much I am willing to put into it. If it doesn’t cost alot would like to keep the truck running. Thanks for any advice.
The first thing I would do is retrieve fault codes
Are your plugs up to date?
What engine do you have?
I would bet it needs new plugs but before I took it in for any work wanted to get some suggestions. I was just shocked that it did this so suddenly with no prior warning. When I parked it prior to first incident it was running fine. Has the V8 triton.
Thanks for the comment.
Oh Boy, lots of luck changing the plugs on that! I would check the U-joints first.
You might also carefully check the intake tract between the throttle body and MAF sensor for any air leaks due to cracked hoses, loose clamps, etc.
Thanks to you all for suggestions. Spoke with local repair guy who I trust, well presently. He believes it has to do with the plugs. It was a company vehicle and not sure how well it was maintained. Will post up date.
You might check the tires for liquid. Repeatedly inflating a leaky tire with canned “fix-a-flat” can result in the shaking you describe.