I noticed a few days ago that when I get to just over 70mph I get a slight vibration in my truck. I can see it in the passenger seat but I don't feel it in the steering wheel. Could it be tires that need balanced? I had the same issue during the winter when I had snow/ice in my front wheel.

Also, I noticed that when I get on the gas, to pass someone for example, I can hear a louder rumble-like noise. I use to be able to hear a whistle/turbo noise before. I can also feel the sound in the gas pedal, if that makes any sense. It's really hard to describe so I'm doing the best I can. I really don't want to take it to a garage if I can get a rough guess as to what to look for. I checked the air intake but I'm not really sure what I'm looking for. I did notice some oil around the oil cap, but I've been keeping an eye on it to see if it's leaking or pooling up. Any help would be much appreciated.

 

Could be a couple things. You may need to have your tires balanced. You may also want to clean your throttle body. Depending on your mileage you may also need some new plugs. Also it could be your u joints are going bad or your drive shaft is out of balance. Just a few things off the top of my head.

 

check your u-joints, shake the driveshaft and see if there is any play

 

also jack the front of the truck up (both tires off the ground) and grab the top and bottom of each tire and try to shake it, if it moves much then its most likely the hub assembly, if you feel just a slight amount of movement it could also be a ball joint thats bad.