black soot in/around the outside of tailpipe?

I noticed that I have black soot in and around the outside of my XJ's tailpipe. I searched the forums and reference has been made to unburnt fuel? Is this normal??

The Jeep is an unmodified 2001 with ~39,000 miles (highway mileage is ~22 mpg.) All seems to be running just fine, however it just seams quite odd that other vehicles exhaust tailpipes look so much cleaner…

Is the XJ’s 4.0 engine known to be a dirty engine with a sooty tailpipe?

Many thanks in advance for any info/advice.

edward,
austin, texas

I think there is a pervert in the neighborhood, that left lip soot on the outside of your exhaust pipe. I know not funny.
If you "extended idle" a lot, they will sure enough soot up. The color of the plugs is a lot better indicator of what's actually going on. You don't have to pull them all, one or two out of the center will do.
My exhaust pipe is typically pretty sooty inside (I idle a lot and do a lot of slow speed driving), but my plugs are mostly light Grey, almost bone color. The exhaust pipe usually cleans up around the end, after an extended run up the interstate.

The soot around the pipe is normal. If you didn't have any, I'd say something would be abnormal.

Mine does the same. I chalk it up to alot of short distance driving, and idleing in the driveway to warm it up in the mornings, and alot of stop and go traffic.

Spark Plugs can tell you a lot about your engine :thumbup:

http://www.advanceautoparts.com/english/youcan/html/ccr/ccr20030701sp.html

I just changed my plugs probably a month ago and they looked just fine, other than being short little nubs for plugs, they looked just fine.