when i put my truck in drive or reverse there is a slight but noticeable knock. however when im on an incline from park to drive or reverse its a loud knock. transfer case or drive shaft? u joints are solid. very little play in the rear end.

also, these 318 have *****. pulling power and such. but mine, like if im going up a hill. i lose speed rapidly and i feel like a tractor trailer going up hills. im thinking a tune up will fix this or is that just...how these trucks are?

 

Well, the plenum isn't an issue. Cat may be clogging, O2 sensors may be getting tired.

When was the last time it was tuned up?

 

Are your U-joints greaseable? If so, try greasing them. Have the joints ever been replaced being that your truck is a 1997 model? The bearing caps of the U-joints may have some wear to them.

As for the sluggishness of the 5.2, a good tune-up (plugs, wires, cap, rotor, air filter, clean throttle body, PCV valve and check for any vaccum leaks) may help. Has the timing chain and gears ever been replaced, as a sloppy timing chain can also cause sluggishness.

 

im thinking along the lines of tune up, bad sensor and clogged cat. as for the knocking the joints have been changed since the birth of the truck but im not sure how long ago and if they are greaseable. i will check today when it gets day light. thanks guys