Hi everyone from Nettleton, MS!
Just bought a 2001 Super Crew F150 with the 5.4 Triton motor about a week ago.
Previous owner took pretty good care of it, but don't like the super loud exhaust. But that's for another day...
The truck has this weird clatter type sound that is repeatable:
1. When I am revved up over 2k rpms and let off the gas suddenly to coast, for a second or two it makes this clattering/knocking noise. Also while coasting at speed, if I very gently touch the gas it makes the same noise. If I touch the gas anything over super gentle, no noise at all.
2. It makes almost the same sound when I first crank it up, usually first thing after it has sat for awhile. The noise lasts for a second or two and it gone.
3. I let my daughter drive it the day I first bought it. She's not familiar with trucks and shifted the transmission into "1" on the column. It started revving pretty high (not redline) and as soon as she realized what she had done, she let off the gas. The clatter/knock was very apparent as it decelerated from high rpms.
Over seen posts about the timing chains and tensioners, about the cam phasers, etc. but none of those threads exactly describe the noise in hearing.
Just changed the oil yesterday, motor craft spec everything.
Could it be an exhaust issue because of this loud muffler and turn down pipe they thought would be just awesome to install right under the cab, or maybe spark plugs need changing? I can say that it doesn't have the acceleration I think it should have.
Anyway, any help would be appreciated. I really like this truck and hate to think I bought it and it has a big problem.

 

You should check for loose spark plugs - use a torque wrench, 28 ft/lb.

 

Ok, planning a coil and plug job soon, anyway.
But if it was loose plugs, from what I have been reading, it would make the rattle noise most of the time especially during acceleration, right? That's not the noise I have.

 

Hmm - what about the cat converter heat shields?

 

You might also check the pcv valve. I just had a pcv that would rattle like crazy under certain vacuum conditions. Turns out the short rubber hose that connected to the pcv was kinked and wouldn't allow enough airflow through the valve to keep it open.

 

Without anymore defining info it sure sounds like the timing chain tensioner guides have worn letting the chains slap the front over.
Here is why; the tensioners are oil pressure actuated one per side.
At initial start, the oil pressure is just building within the passages regardless of the indicated pressure.
Beside this, the oil pressure may be lower on an aged engine.
As you drive and let off the throttle the oil pressure drops and chain tension varies with camshaft load and rpm something like a whipping rope.
I hope it's something less serious.
Very often the use of heavy oils beyond spec causes excess wear on these tensioner guides especially at cold start when the oil viscosity tends to be max until it thins down with heat.
Just as a point of reference, my 4.6 has 229,000 miles and still perfect running and quiet. Oil pressure is hot idle 25 psi, running at speed is near 50 psi depending on outside temperature.
Good luck to you.

 

Oil pressure is related to engine speed and not throttle position? And once it gets to the pump relief pressure it isn't dropping until the engine speed drops to the point where the oil pump turns slow enough the relief doesn't have to open to keep the pressure from exceeding the set point. Don't believe your truck has cam phasors.

 

Correct, 01's don't have phasers.

 

You guys are giving me lots of good information and things to check on. I'm a tool maker at a major auto manufacturer so I can thankfully turn a wrench, so if you guys can give me anything else to check out let me know please.
Thanks again so much!

 

Mine had a similar rattle (97-4.6), was a bad cat on drivers side, cats break down inside and can cause a rattle at certain times,hoped it was the heat shield but no such luck!.

 

Well guys, it was a loose plug! It popped this morning in the Autozone parking lot.
I used the Dorman kit they had there as there was nothing else available, and used plenty of red locktite on the insert.
It's apparently been loose for awhile, I noticed a HUGE difference in throttle response afterwards.
And it was the far back plug on the driver's side bank too. It was a booger to get to but my son and I did it.

 

Chalk up another for glc...

 

Ok guys one more thing. I didn't have a CEL before this happened, but after the repair now I have a CEL (service engine soon) on. It stayed on for the 30 mile ride home.
Will it eventually reset or do I need to reset it?

 

Disconnect the battery for a few minutes and see if it comes back on. If it does, get the codes read.

 

Ok will do and thanks for your help.
There's a couple of things concerning me after driving it for awhile tonight.
One, we didn't unplug the correct injector on the 15 mile ride home with the blown plug, and I'm concerned because the cel was flashing for part of the ride home. It is now just on constant without flashing.
Two, it still has a sputter to it when overdrive kicks in and I very slowly give it gas at around 1000 rpms.
I'm hoping I don't have another plug getting ready to blow out and that it just needs new plugs and COPs.
The engine really picks up much better now though. When I give it gas it accelerates smoothly except the time mentioned above, and I don't hear that tick exhaust leak sound anymore.
Just because it's sputtering some doesn't indicate a plug ready to blow, correct?