BrokenSockets
NAXJA Forum User
- Location
- Ayr, Ontario
Is there any reason that RS12YC would not be a suitable plug to use in the 4.0?
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Plug question - RS12YC?
- Thread starter BrokenSockets
- Start date
NGK is not necessary for a coil pack engine.
Here's some information from Champion that lists specs on both the 401 and 412 plug:
http://www.federalmogulmp.com/en-US...n Spark Plug Copper Plus Heat Range Chart.pdf
I run the 412 in both my 1997 and 2001 and have not had any issues that I know about.
Here's some information from Champion that lists specs on both the 401 and 412 plug:
http://www.federalmogulmp.com/en-US...n Spark Plug Copper Plus Heat Range Chart.pdf
I run the 412 in both my 1997 and 2001 and have not had any issues that I know about.
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Sidewinder CC
NAXJA Forum User
- Location
- Canton, Michigan
RS is a tapered seat plug. The RC is a gasket seat plug. You need a gasket seat.
Use RC12LYC.
In '99 Chrysler switched to the RC12ECC (double Copper) plug when the coil rail was introduced.
RC12ECC is a hair hotter than the RC12LYC plug.
The RC12LYC plugs were used from '93 to '98'
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Sidewinder CC
NAXJA Forum User
- Location
- Canton, Michigan
.Here's a spark plug application chart:
- Location
- Southern Maryland
where does that info come from? wonder why 99 is in the 00/01 category
Sidewinder CC
NAXJA Forum User
- Location
- Canton, Michigan
The data comes from the Champion and NGK websites.
In '99 Chrysler introduced the RC12ECC plugs for their coil rail 4.0's (Grand Cherokee '99) and simply made them applicable to the '99 XJ as well, even though it was still a distributor 4.0.
If you look at the Emissions decal on your firewall you'll see RC12ECC plugs listed.
- Location
- Southern Maryland
99 ignition is same as 98 ignition, if they change the reference info for inventory control convenience then the technical difference is moot
BrokenSockets
NAXJA Forum User
- Location
- Ayr, Ontario
Thanks for the info on the plugs - I picked up a set of rc12lyc today.
I figured out that the 6 rs12yc are actually for my Benz e320. Just got mixed up onto the shelves full of xj parts and scraps. Also sorry for not being specific that this was a question for a 96.
I figured out that the 6 rs12yc are actually for my Benz e320. Just got mixed up onto the shelves full of xj parts and scraps. Also sorry for not being specific that this was a question for a 96.
