need some guidance

[mms4040]

i have a 99 f250, with 160,xxx that i just bought
here is the problem,
at idle it sounds like a kind of knock, deff. a noticeable noise, than when u reach above 800 rpm it diminshes completely..
i believe this to be an injector, but i would assume it would smoke a bit if it was,

all help would be greatly appreciated thanks, james

[woodnthings8]

It could be an injector, but it could also be in the valve train. Had a friend that chased a knock. Nothing could be found, so the tore the whole valve train apart thinking a bent pushrod. Nothing was found, so they put it all back together and the knock went away.

[jesilvas]

Could just be the #8 AD 'long lead' injector that can routinely knock with no problems.

[woodnthings8]

Originally Posted by jesilvas

Could just be the #8 AD 'long lead' injector that can routinely knock with no problems.

#8 LL is an AE injector, the rest are AD's. His 99 most likely does not have a LL injector in it though.

[jesilvas]

Yea I knew it was different, but couldn't remember what code the rest were.

[murrell]

mine has the same problem its an 01 with 186,000 a noticable knock at idle but goes away when accelerated. I was told it was injector. it drives me crazy but it has done it for 30,000 miles now and no smoke yet.

[jc82chevyman]

stick your ear down to your trans bell housing your problem sounds like mine and I think my torquew converter is going out