I have a 1998 f150 4x4 4.6 Romeo sohc with 150000 miles its making a noise very similar to a bad power steering pump except the noise is coming from the left valve cover timing chain area I took the serpentine belt off and there is no noise checked all the pulleys didn't find anything wrong put the belt back on noise comes back it does not make the noise at idle well at least you can't hear it but when you accelerate the noise makes itself known and gets louder and louder any one have any ideas