Yeah the new 08+ 4.7L have cylinders heads similar to the Hemi in that they have two plugs per cylinder. One of the plugs has a 30k mile interval and the other has a 90k mile interval. Not sure why, but that is what I understand from reading around.

 

Apparently, the emissions help from two spark plugs in the Hemi was worth re-designing the 4.7's heads.

 

Who said the OP had a 4.7? And the OP said he has MSD and so when did the 4.7 come with MDS? LOL

Or am I missing something?

 

Sorry weed, I think I started that....I thought the Hemi had plugs like the 4.7, with the 90k bottom ones made of a different material than the 30k top ones...i didnt realize the hemi had intake/exhaust plugs

 

Dont feel bad, Ive never laid eyes on a 4.7....LOL

 

I had a wizard at NAPA tell me the 4.7 is the Hemi. Har, har.

 

Sorry, hadn't managed to log in for a while.

Here is a pic of plug colours, half the cylinders are the whiter colour, half are the brown colour, if they all varied a bit I wouldn't think anything of it but they are all exactly one or the other.

Which cylinders shut down with the MDS?

Any ideas appreciated.

 

The brown plug seems to indicate a correct mix and a good working engine.
The white plugs.....well they almost look like they are unused??
We really need a decent set of close up
pics looking "end on" to the plug and a side view.
Try using your camera on macro mode to get these close ups.
There's a lot you can tell about engine efficiency from spark plug colour and condition.
Al.

 

Here are better photos, previous was taken on my phone.

Thanks

 

Well from what they look like, they're OK apart from some normal wear.

Here's a colour chart for you to look at.
http://www.dansmc.com/spark_plugs/sp...s_catalog.html

And a good article to read plugs a bit more in depth.
http://www.4secondsflat.com/Spark_plug_reading.html

Al.