Knocking noise 4.6 3v

[pami9899]

Hey guys, I have an 08 ford explorer 4.6 3v,116k miles,2nd owner,I have an intermittent knocking noise at hot idle, you can hear it sometimes from the cabin ,I have a video attached what do you guys think it could be ?

20200406_162432.mp4

drive.google.com

 

[vipersinu2]

Try changing those coils.
They are aftermarket. Could be throwing off the timing.

 

[pami9899]

Try changing those coils.
They are aftermarket. Could be throwing off the timing.

The noise was there before I replaced the coil,I was having a shudder, it fixed that problem

 

[94Eddie]

It sounds like it might be an exhaust manifold leak which is a somewhat common problem on 4.6L 3V Explorer engines.

 

[pami9899]

It sounds like it might be an exhaust manifold leak which is a somewhat common problem on 4.6L 3V Explorer engines.

I do have that problem but only on cold start, not hot idle like the video

 

[loooney2ns]

Check the spark plugs. One could be loose or broken. That year uses the crappy 3 piece plugs. If not, it sounds like a bad bearing on the crank. Probably a rod bearing. That would be strange for a 4.6L.

 

[Explorer_PL]

That sounds more like a bearing (what Loooney said), not exhaust or spark plugs. For a moment I thought maybe one of the timing chains hitting the front cover or valve cover. Another possibility could be valve spring ?

I am afraid taking the front cover and valve covers and inspecting everything may give you some answers.

 

[boominXplorer]

Sounds more like a tapping than a knocking. Cam followers and lash adjusters need replaced. You can do these without retiming the engine if you have B+ skills. Wouldn't be much harder to replace solenoids and phasers while your there(could also be the noise). You'll need the cam wedge tool to get it done.

 

[Ruddy]

Sounds a little louder than my 126k 2010 motor. After my research I think it's the cam phaser lock pin banging back and forth slightly. If that is it, it will go away when increasing rpm. That makuloco guy recommends using the thicker 5-30w oil that will cushion that pin among other things.

Idle phaser knock noise:

 

[loooney2ns]

I've been using 5W30 since I got my Explorer.

 

[pami9899]

I have been using 5w30 ever since I bought it at 65k, now it is at 116k miles, that noise usually happen when restart the trucks while the engine, not all the time,I pop the valve cover I don't see anything abnormal

20200202_162953.mp4

drive.google.com

 

[pami9899]

I also that rattle noise those 4.6 be making drive thru when you accelerate