Senior Contributing Member
Car: 2005 Chrysler 300C
Join Date: Feb 2005
Location: New Jersey
Thanked 19 Times in 14 Posts
Just because one plug looks good, does not mean they will all look the same.
If you are going to check them, you should check them all. And if you are
already going to go thru the process of taking them out to check them, then
you should replace them.
You say your car is running fine now, but you will be surprised at how much
better it will run after you change the plugs.
Over time, the gap on the plugs gets wider due to wear, and will change how
efficiently the plugs can ignite the air fuel mixture.
Because its a gradual thing, you won't notice it as it happens. But over the
course of 85,000 miles, I bet the gap on your plugs is way out of spec now.
Also, changing them will give you better fuel economy and more power. It might
not be much, but its worth the cost of the plugs and a few hours of your time.
Do a search for "spark plug replacement" on this site. There are threads that have
plenty of pictures on how to do this. Most are for the 5.7 engine, but its virtually
the same for your 6.1.
I love my Jeep!!
As GoofyTimL says: "thats just adolescent"