charles pearson

Hello, I was wondering if one of you could help me figure out why my 04 CL55 is blowing black carbon all over my exhaust tips and rear bumper. It looks real distaste full for a benz.

sprins

You mean you have black tips or is there actually lumps of carbon flying out the exhaust?

In the case of black tips: That's normal. I have an SL55 and S55 and they are completely black. I cleaned them the other day, which looks fresh, but in no time they go black again.

I believe AMGs (the 55K engines) run a tad rich and that is the cause.

charles pearson

Really! I dont like that, my SL55 doesn't do that. Yea my tips are all dirty black, I like the shiny chrome look.

DFW01E55

Mine have looked nasty over the past few months as well.
I've come to the conclusion that it's because the car runs rich to start with and the winter blend gas that we get here in DFW. That might not be true, but it's convenient.

sprins

Yes it will. Just give it some time

Polish it off with aluminium polish or something. It's a ***** getting it off, but when finished you'll feel good again, until they turn completely black again in 1.000 miles.

It's not the gas. I always pump high quality Shell V-Power (98 oct. with cleaning additives) and I've got the same. My guess is it just runs rich all the time.

charles pearson

I'm taking the damn car to the dealer next week, i'm pissed off right about now because even if it's running rich that needs to be fixed. I always make fun of people who have those ricey cars and when they get on it all kinds of black smoke spitts out of their exhaust. Thanks you all for your input.

trumpet1

Listen guys. I found (by accident) that the best thing in the world to get rid of the carbon residue off of chrome/paint is a product that you can buy at Home Depot called "Soot Out". It is designed to clean outdoor grills but I discovered that it gets the blue sooty appearance and carbon buildup off of chrome in seconds!!!! Simply spray it on your chrome tips, let it sit for about 15 seconds, and the soot just falls off. I would reserve using it on paint but I tried it and quickly rinsed it off with soap and water and their appears to have been no damage done. No matter which you put it on, paint or chrome, have soap and water quickly ready to wash everything off immediately after using.
I keep it handy just for cleaning my chrome tips and they look new all the time. Cleans dust off of wheels very quickly.

JDB

That "Soot Out" stuff sounds like a time saver, but as you said, be VERY cautious around painted surfaces. Don't forget that your wheels are coated with a clear coat and should be cleaned with the same sort of care that you would give to the exterior paint. If you leave a strong cleaner on the wheels for an extended period of time, or apply it when the wheels are hot, you MAY damage the clear coating on the wheels. BE CAREFUL!

By the way, I have the same sort of black carbon build-up on the lower portion of my exhaust tips on my CLK63 Black Series and my CL55. I never gave it a second thought, just thought it was the result of the engines just loafing along at low revs most of the time. Now, if it were there after extended 100+ mph runs, I'd be concerned . . . but, I also probably be incarcerated, the way the enforcement of the speeds limit has increased in my area.
JDB

trumpet1

Yes!!! Try it out cautiously at first especially on painted surfaces like wheels. You are exactly right.

It is very strong but I never saw/see any damage to my chrome on both my motorcycle exhaust tips nor my MB. I think getting it off very quickly is why.
The active ingredient I believe is potassium hydroxide.

charles pearson

Thank you all for the input and i'll be buying me some of that tommorrow, but aren't u guys concerned with why it's doing that in the first place? Cars are not suppossed to run rich and blow all of that gook out, it looks like the stuff Doc Holiday had in the 19th century

trumpet1

Which grade of fuel are you using???

sprins

I think there is a good reason for those engines to run rich. I believe that running rich keeps the engine and exhaust relatively cool, while running lean will relatively heat up the engine and the exhaust. Perhaps there isn't enough cooling power on the car with such a big engine to have it running lean (with clean exhausts).

My neighbour has a Carrera RS (964) that burns fuel rather nicely. Hit exhaust tips are always clean no matter how hard he drives it.

charles pearson

93 octane

trumpet1

Sounds like you're using the correct grade. If it were me, I would experiment on a few tank fulls with lower octane grade just to see if the carbon diminishes or worsens. Not that I would continue that change, just for experimental purposes only.

What "sprins" said makes sense too. The higher octane fuel detonates with more resistance. Makes you wonder if the engine may need to run hotter

If your dealer doesn't give you a satisfactory answer, you may want to talk to Bob at Renntech. He may have some insight into this.

Have you compared your car to other ones like it in your area? If they all are doing it, maybe it is normal. I don't know. I just know mine smokes a tad right after startup. I was told this is normal.

alx

most factory blown cars run rich to be on the safe side. this is normal. some run reach-er then others. this is also normal. i've seen most amg cars running close to 11:1 a/f under medium acceleration. this will cause soothing.

running rich minimizes leaning out under boost that can have catastrophic results due to detonation (read - pistons cant be used even for ashtrays

this is also done to provide a safety zone in case you run a tank of lower-octane gas that might cause detonations.

you should not be concerned.

alex
few cars

charles pearson

Ok thanks i'll just keep cleaning my pipes, thanks to all of you, you all have been very helpful to me, Ranger Out!

grane

I'd try a big bottle of Techron every other tank of gas. I use it here and my carbon problem is not as bad as what you describe by any means.

Hazy1

I also laugh when cars belch black smoke on full throttle, so I'm kind of paranoid about my car being one of them. My E55 is closing in on 60k miles and the tips have always blackened. A couple of weeks ago my wife was behind me in traffic so I floored it to see if anything was amiss. She saw no smoke nor smelled anything out of the ordinary, so I don't think we have anything to worry about.