Plug Looks Richer on Left Side?

[s3steve]

I've just changed the spark plugs on my '06 RT and the left side plug looks like it's running richer. It's a lot darker compared to the right one. Right side is a nice tan brown and the left has some tan but mostly black.

 

Any reason for this?

 

The valve adjustment was done by the dealer 5000 Kms ago so they should be OK but I haven't checked them.

[dirtrider]

Morning Steve

 

Unless you removed those plugs right after a high speed run after doing an ignition chop then a coast out they won’t tell you anything useful.

 

I see a lot of dark plugs that are pulled after a short run or maybe a cold start then a quick shutdown. Dark is perfectly normal under those conditions.

 

With twin oxygen sensors on the modern BMW’s it’s pretty difficult for them to run anywhere near rich for most operation once warmed up.

 

 

 

[s3steve]

Nope, no plug chop just a 15 minute ride to run in the Stabil before the winter layup last November. I'm not worried, just thought it odd.