02 Lariat with 200,000+ 5.4 just bought it a month ago. It was shaking when I started it at the lot and when driving. Thought I could diagnose and fix it but I'm stumped. At idle the engine has a very visible shake like as if the pass. side motor mount is broken (looked at it and didn't see anything wrong). Then when accelerating and particularly when it seems to shift into a higher gear it really shakes severely. Cleaned the MAF sensor after it was suggested here to no avail. I'm leaning heavily towards the torque converter. What do you think??????

 

Could be a coil pack.

 

More than likely could be a coil pack because that's what is wrong with my truck and it does the exact same thing

 

If you go to an autozone or a store like it they can scan your engine and tell you which pack it pad.

They're actually not that hard to replace. I'd look up some videos on youtube. My dad and I replaced one on a 2004 trailblazer. It took like 3 bolts and 15 min of time and the car was running great. The part was $75 and most shops around here will charge like $350 for this job. The dealership charges $500....