this was a post i put up a little bit ago:

"i have a noise coming apparently from the driver's side of my engine that i haven't heard before. it's kind of a high speed tapping or chirp. if i hadn't just replaced it, i'd suspect my lift pump. it only seems to happen at higher revs (around 2k) but is very inconsistent. doesn't happen when i rev it from under the hood. infidel suggested replacing the overflow valve, which i intend on doing, but was wondering if anyone has any idea what this sound might be and if it is safe to drive or if i might damage my injection pump or anything? (there are no other symptoms that i know of other than the sound, although i am seeing more dark smoke than i am used to, but that started long b4 the tapping)
thanks"


i just wanted to add that since driving it again, i have noticed that this noise only occurs in the rpm range from just below to just above 2000 rpm's. just wondering if anyone might have an idea or theory as to why it would only happen in such a narrow rpm band?

 

Mine does the same thing. No idea what it is. Maybe overflow valve. Try pming MDKram. He's very knowledgable.
Andy

 

i have a new ofv, just haven't had time to put it in, plus it's snowing and i don't want water getting in there. somehow i don't think that's it, but we'll see.