4.6L top end noise
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Junior Member
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4.6L top end noise
My '99 has made an awful sound since I bought it (used) when cold. It sounds like a pully going bad with the awful screaching sound. The problem is that it isn't the pulley.
I've listened to the front of the engine with a probe and it seems to be coming from the area of the left cylinder head. It's in the front where the timing chain is, under the coils.
I'm really hoping this isn't another problem with F150 motors. It does go away when it gets warmed up or if I bump the throttle when it's cold.
I can post a sound clip if it helps.
I've listened to the front of the engine with a probe and it seems to be coming from the area of the left cylinder head. It's in the front where the timing chain is, under the coils.
I'm really hoping this isn't another problem with F150 motors. It does go away when it gets warmed up or if I bump the throttle when it's cold.
I can post a sound clip if it helps.
Technical Article Contributor
Joined: Dec 1997
Posts: 9,417
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From: Windsor,Ontario,Canada
Have you eliminated the belt and accessories as the possible cause? This would involve removing the belt, then starting it, when it is cold, and listening to see if the noise is reproduced. Do not run the truck for more than a minute with the belt removed. The water pump is not circulating water through the cooling system.
Regards
Jean Marc Chartier
Regards
Jean Marc Chartier
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I haven't done that because the noise isn't constant. It's more of an on and off kinda thing.
I'm starting to understand the trouble customers had explaining problems to me when they came to the dealership
I'm starting to understand the trouble customers had explaining problems to me when they came to the dealership
Junior Member
Joined: Dec 2004
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From: SE Tennessee
My '97 4.6L also makes a noise tho it sounds more like from the front of the motor instead of on top. Sounds more like a rattle, kinda like a bearing going bad, especially bad on cold startup and seems to last until the motor is good and warm. Sound seems loudest when listening directly in front of the radiator so am wondering if the stock viscous fan could be bad. No coolant leak so I doubt the water pump is going bad. No, haven't removed the serpentine belt to isolate whether an accessory or the motor.
For months, the rattle was intermitent on cold startup; now quite loud on every startup. I once took the truck in to the local Ford dealer who kept it overnight but said he couldn't find the noise even tho he heard it (??).
Another message thread mentions a "squeak" caused by the starter. Guess we need a sound clip to let everyone determine if the sound is a squeak,rattle,hiss or whatever.
My rattle doesn't seem to affect operation or performance in any way....mainly an embarrasement that draws mucho stares and some anxiety on how much inconvenience a breakdown will cause.
For months, the rattle was intermitent on cold startup; now quite loud on every startup. I once took the truck in to the local Ford dealer who kept it overnight but said he couldn't find the noise even tho he heard it (??).
Another message thread mentions a "squeak" caused by the starter. Guess we need a sound clip to let everyone determine if the sound is a squeak,rattle,hiss or whatever.
My rattle doesn't seem to affect operation or performance in any way....mainly an embarrasement that draws mucho stares and some anxiety on how much inconvenience a breakdown will cause.