trying to not buy a new motor with the possibility of more problems
i have the 3.0ff automatic in a 2002 ranger xlt 2wd. its had a misfire in cylinder 6 since I've had it. I've put on about 50k miles and it runs good and what not. but its very shaky. very weak when trying to take off or accelerate hard.
if i take it on the interstate the ups and downs of the hills will cause it to over heat. not terribly but well above operating level.
it has new plugs wires and coil pack. I did a wet and dry compression test and cyl 6 had absolutely no response to either test. the gauge never moved.

any suggestions will be greatly appreciated

motor has 140k so hopefully it doesnt need to be swapped.

 

At a minimum you will need new heads on your engine
But until you take the head off the #6 side you won't know if its a piston issue, unlikely but possible

 

ive had quite a few tell me it could be a burnt valve as well?

 

That valve that may be burnt is in the cylinder head. So as RonD says, you'll have to tear down your truck to the lower engine block. Once the driver side head is off, you can manually crank your engine and do a simple piston height check to determine if you have lower engine damage. It is not likely, but if your piston head heights are off, you'll know right away if you'll need a new engine.

Sounds a lot like you need head work and it may just be a valve leak. Here is a great video where a dude has potentially the same problem you have, but on cylinder 5. Even shows how he diagnosed it as a valve leak after the cylinder head was off.

EDIT: Diagnosis as being a head issue at

.