Help with this noise!!
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Senior User
Joined: Feb 2008
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Help with this noise!!
1975 F250 390/C6, cam, headers, 4bbl. For months now i have been chasing a tick or click or hiss or who knows what, leaning out of the truck straining to hear. I'm stumped. I hear it most when the truck is warmed up and at part throttle, around 1500 rpm especially. It really sounds like an exhaust leak and is just bordering on being harmonic. I've changed header gaskets twice and there was never a sign of a leak, the collectors are tight with no signs of leaks, and i cant isolate it to any particular cylinder/valves with a rubber hose or steth. it runs fine and i dont hear the noise under hard acceleration. i've checked for bent pushrods, lifters not turning, lash, etc... What else can i check??
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
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From: Simi Valley, CA
Possible U-Joints or drive shaft center support bearing (if equipped with a 2 piece driveshaft.
Old used car dealers trick. Find a street with no traffic, drive alongside the opposite curb, open the door and listen closely.
Old used car dealers trick. Find a street with no traffic, drive alongside the opposite curb, open the door and listen closely.
Thread Starter
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Senior User
Joined: Feb 2008
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sorry, no u-joints under the hood
. i pulled the valve cover today and ran it, sounds like its coming from the AREA of number 5, but i still cant isolate it with a rubber hose or steth, cant even hear it really unless i take the steth out of my ears and just listen, all the pushrods are straight, lifters are turning (though some more sporadically than others) and the lash is all good.
. i pulled the valve cover today and ran it, sounds like its coming from the AREA of number 5, but i still cant isolate it with a rubber hose or steth, cant even hear it really unless i take the steth out of my ears and just listen, all the pushrods are straight, lifters are turning (though some more sporadically than others) and the lash is all good.
