On October 29, 2004 I purchased my F150 (His name is Rocco), and I seemed to have no problem with it. It had 82,072 miles on it when purchased. Since then, I've driven to Atlanta and Tennessee twice. I now have 87.800. I've put roughly 5500+ miles on it. Well, while I was driving on my way back home from thanksgiving, I got it up to 85MPH, and I felt the gas pedal vibrating. I lifted up on it, and I felt it again. It didn't stop until I got it under 85. There was no steering wheel vibration, no nothing, just the gas pedal, which made me think that it was coming from the engine. I consulted a friend, and he says that I may need a tuneup (I checked with the dealership I bought it from, and it [tune-up] was not done). Also, I noticed he [Rocco] sounds a bit louder than normal. I was riding along the wall on the freeway this morining in traffic going about 45MPH, and it didn't sound like a normal whirrrrrr sound. It was like you could hear the pistons going up and down, like you would on an older car. It wasn't a bad sound, but I had never heard it before.
A little information:
1997 Ford F150 XLT Regular Cab 4.6LV8
87800K Miles
Could me taking the older truck on the road so much be the reason I hear all of the extra noises, vibrating, etc?

 

Just went outside during my lunch break at work, and the engine sounds like it's tapping and it's running a bit rough....... It's sorta cold outside, but I let it warm up, and it still sounds and feels weird.....