What would be a good test to see If my buddys truck has a rod knocking?I've heard that i could pull one plug wire at time and start the engine and if it stops its knocking on that cylinder.Is this true?Thanks

That's a fact. I think it works more for wrist pins though.

Ok,This is an early 80's S-10 with a V-6,would this method apply?Also would a loose converter to flywheel or a loose flywheel on the motor have the sounds of a rod knocking?Its not a consistant knock,its almost like somethings loose.Thanks

If it's a rod, you should be able to get the engine to 2000-3000 rpm drop her to idle, & as the engine comes down, you will here the knock. If it's a rod it will be pronounced.