I have a 99 F150 6 cyl, I'm sorry I don't know the engine size. I bought it with 30,000 mile and I couldn't find any history on it. I now have 50,000 on it. Ever since I have bought it is sounds like a diesel when you first start it. It makes a noise like a water pump chirp. It also is pinging while driving. It's driving me crazy what sould I ask my husband to try to get rid of these noises? I hate taking it in to the dealer. I use to work for car dealerships for twenty years and I know how much they make off of people.
Any suggestions? I would appreciate all comments. Thanks
P.S. I love my truck I just wish I could get rid of these sounds.

 

I don't know about the deiseling sound, but it could be carbon deposits in the intake and throttle body. Or a clogged EGR system. Change your PCV valve. Another thing it might be is your IAC valve located on top of your throttle body. Check all these. As for the pinging, it would'nt hurt to pour a bottle of fuel system cleaner like STP or Techron fuel treatment in your gas tank. Another way to top pinging is to use 89 octane gas from a quality gas station. I would also suggest a complete tune-up if your engine has alot of miles on it.