I replaced the heads on my 98 5.2 Ram last week, got everything back together (and even put some some spiffy wire looms to hold the plug wires) but there's a loud pinging coming somewhere from near the back of the intake manifold and the truck has very little power. The Check Engine light hasn't yet come on. Today i replaced the cap and rotor but no good. I had someone tell me that i had some wires crossed, i checked and rechecked the wires and they appear to be in the right order.
Any suggestions before i pull the intake back off?

thanks!

- upjeeper

 

Could be the dreaded Intake Plenum Gasket ?

 

Firing order is 18436572 clockwise, just in case. But crossed wires will typically cause a misfire, not detonation. It sounds to me like you dropped something down a holewhich dinged a valve & crushed a ring groove.

Better check compression.