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Is your tailpipe black inside?

Is the inside of your vehicles tail pipe black?

Yes, all 3 cars. Normal

Neither of my trucks have black tail pipes @Mustangman. And in the past if they got black I would be working to correct the problem. And in the good ole days I kept my tail pipes chalk white.

Very light gray is the color of the inside of my exhaust manifolds but all the tailpipes are black and sooty inside. All 3 cars run just great, @Rod_Knox

Maybe it deposits the carbon after a long cooling trip down the pipes or maybe I put my foot into the throttle a bit too much (even the wife’s car and she’s a lightfoot), don’t know.


Same type question as, "Do you smoke after sex?"

Answered the same way, too, "I don’t know. I’ve never checked!

I hate to use the expression, "Don’t know, don’t care," but as long as my cars are running correctly (which they always do) I don’t look up my tailpipe.


If it wasn’t so cold I’d look up mine.

And of course the person did not give much to go on. Is this a new car - one that just started doing this - a used vehicle recently acquired .

He also didn’t say HOW MUCH soot he has. I’ve seen rolling coal trucks with soot all over their tailgates as well as the 8 inch chrome sewer pipe tip they screw to their 3 inch exhaust.

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I’m waiting for the other shoe to drop…
Is there a punch line?

Question: Is your refrigerator running? Yes.

Answer: You’d better go catch it!

‘Chalky white’ used to be the gauge for a good-running engine, back with leaded gas. Now it’s common and normal to see sooty black.

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When I check out a used car to buy I examine the tailpipe deposits.
A little dry soot in a finger is OK, oily soot no.
I’ve never had a car that needed oil added between changes.
My 2006 Toyota Matrix had the cleanest pipe I’ve ever seen, bare bright metal.
The current 2017 Hyundai with GDI had a little dry soot when I got it last July.
Now it’s dark gray inside but no soot rubs off.
I attribute that to a gentler driving style than when it was a rental.

It would be interesting to know whether Top Tier gasoline results in cleaner tailpipes. Do you make a habit of buying Top Tier brands?

I buy TT fuel maybe 75% of the time.
I’ve never seen any suggestion or claim that TT makes a difference in tailpipe emissions.

I haven’t seen that myself, but they do claim cleaner combustion chambers, valves, etcetera. Tailpipes follow combustion chambers.

Oh man. There used to be a bar in town called the Hurryback. So we’d call them up and when they answered we’d say why hurry back, we just got here. Or Do you have Prince Edward in the can? Better let him out. I suppose now you’d be arrested.

At any rate I assume mine are black. The only time I really notice is when I’m trying to polish the exhaust tips. It’s too cold here for that now. Yeah Schools closed for three days, church closed, no meals on wheels to worry about, etc. It’s like a ghost town in Minnesota when the wind chill gets down to -25 or so. We just can’t take it anymore.

Yeah, it’s definitely too cold to be out working on the car. It was a chilly 50 degrees this morning!


Last March I flew home, jacked up the Grand Prix (all 4 wheels in the air) and put all new rotors and pads on it, just to be sure where the brake wear stood (almost as easy as checking them and only 200 bucks). The temperature never got above 27, as I recall and I worked some with gloves on. Takes the fun out of it. Then I drove it back here as fast as I legally could.

It was about 50 here this morning, too (thanks to those guys spilling all that Arctic crap down this way), but warmed into the sunny sixties for a nice long bike ride along the Manatee River.

Going to be 70 to 80 by Friday and it looks like our normal warm weather will be here a while. Surf’s up, Dude!


Burning fossil fuel in any engine creates soot… this is what turns your oil black. So exhaust pipes, mufflers etc will have some soot in them, none are exempt from this. Items closer to the exhaust port will have less because of air velocity and heat… but some sooty deposits, especially near the tailpipe section, is perfectly normal.

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Generally, black soot in the exhaust tailpipe would indicate a too rich fuel mixture, leaving partially burnt exhaust deposits.

This was common in older cars with carburettors, where a flap closed across the venturi to richen the mixture for cold starting. If this was in a car which only traveled a few miles a day, to and from work, then even after the engine had warmed through, there was insufficient time for the deposit to clear. In these vehicles, there also tended to be emulsified oil on the inside of the rocker covers and the oil filler cap.

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Everyone keeps mentioning a too rich fuel mixture for good reason and this is certainly true, it will absolutely make a lot of soot. However modern fuel injected vehicles are programmed to achieve an AFR of 14.7:1. Lets just imagine that a vehicle is able to maintain this correct ratio… It will still have black deposits in its exhaust components.

Excessive soot is a different story…usually your bumper is affected with an overly rich ratio, fuel mileage will also be poor and that further exemplifies a very rich ratio. But even at the perfect Stoichiometric AFR ratio of 14.7:1 will make the inside of the muffler and tailpipe black. Even a leaner AFR will create soot. I can also promise 14.7:1 will not pass the “white glove test” on the inside of any exhaust component. This is simply the normal byproduct of combustion.

So unless your motor oil stays clean and a “see thru” golden color and looks unused for the entire oil change interval, you too have black soot in your exhaust. That really is the long and short of it…

Perfectly normal.