I have a 2002 ford explorer with 140,000 miles on it.?

When i start it i have to let it run for a while before i drive it or the engine will be loud. Does anybody know why this is? If i just start it and drive off it's real loud and feels like it dosn't have alot of power?
The only way i can describe the sound is it sounds kinda like a bus when it's excelerating only not that loud. And the oil and filter are correct and new.
 
Back
Top