I bought my 5.7 Challenger with 40k miles 2 years ago. At 52k miles I noticed a rough idle, so I pulled the plugs and found all 16 Half sooted. There were no engine codes, and to get the car rolling again I threw in some Champion copper plugs which smoothed out the idle.

Anyone experience the half sooted plugs in a 5.7 Hemi? The pictures are of one plug from different angles.

 

Don't see much of a problem. You replaced irridium with copper core plugs?

 

Thanks for the reply

Yes I threw copper in it for now, those were the original platinum plug at 52k miles. I'm planning on some engine work and looking at Ruthenium plugs to go along with that, so I just threw in some cheap plugs till then.

I've never seen plugs soot only on one side, didn't know if this was normal. Seems like blow by, but only one side. Weird in my experience but I'm not a mechanic by trade.

Never worked on a Hemi or any 2 plug per cylinder engines for that matter , my experience is mostly Chevy V8.

Half soot seems normal?

 

I would think it would imply an odd burn pattern in the cylinders..... Possibly dirty injectors??

What plugs does Ma Mopar recommend for the hemi? I know the older engines, (magnums) REALLY dislike rare-earth plugs, and using them could lead to mystery misfires..... Other folks didn't have any problems with 'em.

 

Please disregard the type of plug that is currently installed, it was the plug that created a spark to move the car around.🙂

The sooting pattern on the original factory plug is strange, didn't know if this looked like a common hemi thing.