2004 cl600. i know some members recommend the ngk iridium plugs, but are the stock mercedes plugs you purchase at the dealership copper, platinum, or iridium? i know they list for $19 each, local dealer wants $24, and i can get them on line for $10.15. what material are these stock plugs made out of? also should i purchase 24 connectors for the spark plus as well?
thanks

 

Stock plugs on my CL55 were NGK-R iridium, however if you have Bosch stock plugs they are platinum. When I changed mine I opted to use NGK iridium (NGK LFR6AIX-11)

I did not need to purchase connectors as t hey came as needed.

I believe your CL600 would use NGK IFR6Q-G

I did however change the full set of plug wires at 100,000 miles as some were holding too much resistance on testing.

 

i wasn't aware i had spark plug wires. aren't the spark plugs connected to the coil packs via the rubber spark plug connectors? if so is it recommended to buy 24 connectors along with the spark plugs? do these usually go bad, or get damaged when replacing spark plugs? 2004 cl600.

 

You are correct, the "Spark Plug Wires" go from the plugs to the coil packs. They are still in essence spark plug wires though, just shorter than usual

Heat and use degrades the wires, insulation, etc. Resistance builds up when this happens. You can test your wires with a Ohm meter to check for resistance.

Also you can feel the insulation and see if there are any hard spots, cracks or damage.

 

iv'e been searching for spark plug wires for a 2004 cl600 and haven't been able to find any. the coil pack appears to fit over the spark plugs with the rubber spark plug connector inside the tube on the coil pack.
can you let me know where to get spark plug wires for a 2004 cl600.
thanks

 

Did some research and the V12 ONLY uses Spark Plug Connectors between the plug and coil pack. These connectors (Part #A000-159-00-80), actually can be purchased separately, but also come with complete coil packs.

Yours are probably OK as it seems the coil packs get replaced a lot on the V12's.