Hey everyone I'm new here I have a 1997 f150 xlt 4.2 with 5 speed manual trans my truck has 172000 miles and recently started having a few issues with it. The first being that at idle it runs and sounds fine but when I shift into gear and accelerate there's a ticking or knocking sound the second is that when I'm on the freeway or going up hills I am losing acceleration power if anyone knows what this could be please let me know thanks

 

Take a look at the harmonic balancer on the front of the crankshaft to see if the key slot has worn allowing the harmonic balancer to turn in relation to the crankshaft. There have been several posts over the years where this has happened with the 4.2L V6 engine.

 

If the knocking is under the vehicle it may be plugged cats, that will kill power.

 

Thanks guys for the info I'll check it out and let you know what the update is