Weird Black Soot in my Exhaust

[Orpedcrow]

Are they NOT supposed to look like that?

 

[L31MaxExpress]

That explains why that pipe looked totally normal to me.





On a related note, I don't spend a lot of time looking at other car's tailpipes. Reminds me of dogs sniffing each other's butts.

I only look for diagnostic purposes. I have actually seen engines running so poorly that they have a film of oil inside the pipe. To me it will tell me as much as looking at the plugs. Clean or rusty means the engine is lean overall, a little grey soot is normal, black carbon is lots of WOT or rich overall and a 1-2" soot ring on the outside ofbthe pipe is definitely running too rich.

 

[L31MaxExpress]

I will also add, with direct injection the pipes are always coal black. Direct injection engines have loads of fine particulate soot being emitted all the time. They whole exhaust system will soot up on them when you are light on the throttle and just cruising around. When you go WOT on them for the first time in a while, the exhaust looks like a diesel rolling coal.

 

[Schurkey]

...so the out-of-control EPA will soon be requiring particulate filters on gasoline engines.

I'm so old that I remember when the EPA were the "good guys"; before they became the "crybaby whack-jobs".

 

[Road Trip]

Here's another data point for an exhaust outlet taken from a '99 C2500
with a 454. (All stock, including black box, original-looking cats, no SES
light, no DTCs, smooth running, quiet engine, looks like it's never been
opened up, ~221K miles, no real oil consumption noted, fresh plugs on
older spiral wound wires, dizzy unknown condition, etc.)

To get a better idea of what's going on, as others have noted it would
be most helpful to at least see what your spark plugs look like, (organized
like they came out in a group photo**) SES light, and any DTCs being kicked?

From over here, it does look like there's room for improvement with your
sooty exhaust?

EDIT:

**Here's an example of how to show your plugs so that we can look for
specific failure patterns remotely. (Plug group photo example.)

 

[Pinger]

...so the out-of-control EPA will soon be requiring particulate filters on gasoline engines.

Already a fact in Euroland.

 

[DerekTheGreat]

I will also add, with direct injection the pipes are always coal black. Direct injection engines have loads of fine particulate soot being emitted all the time. They whole exhaust system will soot up on them when you are light on the throttle and just cruising around. When you go WOT on them for the first time in a while, the exhaust looks like a diesel rolling coal.

Hmm, I've seen that a few times on the freeway and thought, "Wow, for a modern car that's pretty bad. My PoS doesn't throw black smoke outta the tail pipe.."

 

[L31MaxExpress]

Hmm, I've seen that a few times on the freeway and thought, "Wow, for a modern car that's pretty bad. My PoS doesn't throw black smoke outta the tail pipe.."

When driven hard my 2011 M56S would actually have noticeable soot deposits on the rear bumper above the exhaust tips. The car was black, so that gives an idea of just how much soot they make. Towing heavier trailers, my mom's 2019 Titan gets the same soot deposit on the bed above the exhaust. It is white though and easier to see.

I worked with a guy that was tailgating at crazy close distance to me in my 2011 M56s on the way to work one morning. I did not know it was a guy I worked with at the time. I got annoyed and slammed it to the floor. His front bumper had dual soot stains on it that lead up his hood from me cleaning out that 5.6L V8s soot into his bumper. He then proceeded to groan at me about to which I responded to him, should not be tailgating people. I told him if he had not been 5ft off my back bumper his car would not be covered in a layer of soot. The direct injected stuff can be plain annoying, a lot of people think the engine is low on oil because of how the fuel pump and injectors tick.

 

[DerekTheGreat]

I'm left wondering how direct injection is a marvel for anything other than WOT. I'll keep driving my old crap, loving it more than I thought possible.