Best way to check for a rod knock

Got a 4.6 sohc v8 and lately there has been tapping coming from the motor when it heats up. I cant tell if its a lifter/lash adjuster or a rod knock. Ive pulled each ignition wire one by one and the noise stays the same. Is this the best way to check for a rod knock?

A mechanics stethoscope is probably the easiest way to determine where the noise is coming from. If the noise is louder at the top of the engine it’s probably something in the valve train. If the noise is louder at the bottom of the engine it’s probably something with the rod/crankshaft bearings.


Thanks for the reply. Yeh used a stethoscope but its really hard to tell seems louder at the top. Just want have an idea what im in for when I take it in to the dealership.

What you just described is the best way to check and see if the noise is from a rod bearing. Since the noise did not go away when you pulled the plug wire this points towards something other than a rod bearing.

What’s directing you to the Dealer for internal engine work? this is probably the least llikely system I would bring to a Dealer to work on.

Thanks.Guess thats kind of a load off my mind really not ready to redo the shortblock now. I was thinking dealership because I want someone who speacializes in Ford modular motors and the closest Mustang specialist is an hour away(dont want to drive or tow it that far) im a little picky about who works on my car lol.