Help with Noise

[sammyapache]

Good day, quick backstory. Purchased about a year ago 2003 4.6 Mercury Mountaineer. Engine was replaced back in 2012 with a 4.6 from Mustang. Truck runs smooth, no lights or anything but it has a noise that sounds like coming from engine. Already replaced tranny, TC and flexplate thinking that it may be the problem. Noise became quieter but still there, had tranny place remove tranny and flexplate again to verify they were good which they were. I attached video see if I can get some suggestions. Hard to hear when in Park or Neutral its very subtle but when in drive it can be heard clearly. Sounds the same from top or bottom of engine kinda sounds like is coming from the rear of the engine that is why we thought it was tranny or flex plate but they both look good when they were checked twice. Both Engine and Tranny are remanufactured. Thought maybe exhaust but took to exhaust shop and they believe is torque converter or flexplate which has been checked multiple times already. Just looking for ideas see where I should take it to, thanks again.

https://youtu.be/YR_HE5NThOw

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[rwt101]

I am not as experienced with the newer engines, because of the timing chains and overhead cams. But that sounds Like a piston slap or bad bearing. It sure don't sound good.
Have you seen any metallic pieces in the oil when it was changed?

Bob T

 

[sammyapache]

I did not notice any metal in the oil on last oil change but was not really looking. Will be doing an oil change soon and will definitely look for some, thanks for the suggestion.

 

[rwt101]

In the push rod engines you could remove one spark plug wire at a time and isolate the noise if it were in a piston or rod. I don't think you can do it with the high energy ignitions. I am not sure of that.
Bob T

 

[Joe in NY]

Instead of removing the plug wire you simply unplug the coil pack and listen for change in noise now a days.

 

[sammyapache]

i appreciate all the suggestions, ill disconnect the coil packs today one by one see if anything changes, thanks.

 

[eeprete]

Use a stethoscope when listening, and even if listening in the hole. Also, an inspection camera can be helpful. I had a similar knock. Engine is getting pulled and rebuilt or swapped. Leaning more toward a rebuild now, since I am seeing an interesting number of cases like this at not very high mileage. Can't understand how the 4.6 in Exp/Mnt's don't have the same reliability as the Town Car/Vics.