kerlyb

2008 GL320 w/ 70k miles. I was wondering if it is normal for the exhaust tips to get black over the years. I'm thinking it's just the soot from the diesel exhaust but there wasn't much during the first 50k miles. Just want to make sure there is nothing mechanically wrong.

If it is normal...how do you clean it off? I've tried brake cleaner and Flitz metal cleaner with minimal results.

alx

Have your driving habits or patterns changed?

Soot is normal if driven hard- especially with diesels. But if it was not there the first 50k and now it is - something has changed.

houseofdiesel

A build up over the years is normal, I used a metal polish on ours when we bought it used 2 years ago, still shiny clean today. Carbon build up/soot is very brittle and needs a good soaking to loosen up, try leaving the cleaner on it to soak it a bit before trying to remove it. I cleaned mine by hand not a polsiher or buffer.
If you notice soot on your bumper or tailgate, this is not normal and needs attention, but a dirty tip is nothing to worry about.

bselph

I used to clean mine monthly with metal polish. But now it is too hard to get off and the chrome is wearing thru(probably from the polish?). I did have them replaced under warranty about 40K miles but the new ones did the same. I think I will just order some new tips if they aren't too high priced.