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The back of all the Corvettes I have owned is a magnet for soot and road debris. Within a couple of days driving it would need to be cleaned and often clayed to get it clean.
Even worse are my rusted brake rotors Those rascals will rust up anytime the car is washed. I bet GM used cheap metal when they made the rotors for my cars.
St. Jude Donor '05-'06-'07-'08-'09, '14-'15-'16-'17-'18
I used to get those black spots on the back of my Victory Red C6. Solution? A nice clean micro-fiber towel and some detail spray. Comes right off. No problem. No big deal.
Of course I, along with most guys and gals here, actually enjoy cleaning our Corvettes. If that's a burden to you, perhaps another car would be better for you.
Just sayin'....
Last edited by ExRedRacer; 02-02-2017 at 11:37 PM.
I'm on my sixth Corvette over the last 27 years - I have more than 600,000 miles in Corvettes - I had two Corvettes that did not show these black spots: one was black, the other Polo Green.... all my other Corvettes - white (2), silver, and Red Metallic Tintcoat - have displayed this - it's normal.
Maybe you should seriously considering getting a different car.... living in a constant state of frustration isn't healthy.
Not sure why you are upset. The car is running normally. All and I say all cars with catalytic converters throw this kind of soot. It is the nature of the beast. With the Corvette, especially the C4, C5, C6 and C7 the soot gets caught in the disturbed air behind the car and is thrown against the rear fascia. I have a great picture I took of the rear fascia on my C6Z taken after a track session showing a bug splatted against the rear fascia. If the vortex behind the car can do that to a bug that happens to fly into it the light soot particles will do the same.
If you use the throttle a lot you will see more spots than if you are taking it easy around town or driving on the highway.
As far as I am concerned it is a problem that you want to have as not having spots back there means the car isn't running hard.
Bill
Bill, I agree it's totally normal, but go one step further. I had this even worse on my 08. That car had no cats. Full length LT and NPP. And the rear of the car was always "sooty" after even a short drive.
it's just like youve explained. Design of the tailpipe against the flat back.
It's amazing the amount of crap that gets sucked up and deposited on the back end of a C6 or C7. It gets dirty first, and just going down my very long driveway will show it.
I sure as hell wouldn't sell the car because my *** end was a little grimy.
I understand that the OP was concerned that there was something seriously wrong with his car, but by now, I hope he understands that this is just the nature of the beast.
OP, you are a poster for the records!
If your backside is getting dirty you should change to Cottenelle. With ripple technology it gets your bum so clean you can "go commando"!
The area immediately behind modern aerodynamic cars is a low pressure zone in motion. Since nature abhors a vacuum, air and everything carried in it moves from areas of high to low pressure, IOW toward the rear of your car. The higher the speed, the great the volume of air moving in that direction.
Sometimes that air mass is carrying dirt, sometimes it's road tar and other oily residue deposited by all the other vehicles on the road surface. Only a small part of it is coming from your car. It's another part of the price you have to pay for higher performance, and it will always be the dirtiest part of the car.
Cars and trucks shaped like bricks don't have this problem.
I used to get those black spots on the back of my Victory Red C6. Solution? A nice clean micro-fiber towel and some detail spray. Comes right off. No problem. No big deal.
Of course I, along with most guys and gals here, actually enjoy cleaning our Corvettes. If that's a burden to you, perhaps another car would be better for you.
As others have stated its normal. The condensation pools and comes out as tiny droplets or mist from the tail pipes. Those droplets form on the inside of the pipe as exhaust gets farther away from the engine and cools. As they form and are pushed out they come in contact with the black soot from the combustion process inside your pipes. Seriously nothing to worry about. Also more common this time of year in cooler weather as condensation forms more readily when its cold. Warmer temps mean higher exhaust temps exiting the tail pipes hence less water droplets forming.
2016 C7 Stingray.
2800 miles.
I visited 3 dealerships and they cannot find the way to fix it. Does anyone has the same problem?
I think the car is lemon.
The spots are covered all over my trunk. I tried different gas stations .Checked the oil. Nothing. My son is kind of mechanic and he thinks there is a serious issue. I am tired of cleaning the back of the car and I am afraid it will be more issues after the warranty.
Does anyone has any idea how to fix that or shall I continue talking with GM ?Please advise.
There have been several gratuitously rude and mocking replies to this gentleman's post. He wants to know whether he even has an issue, including a legitimate concern about a possible engine fault that could cost him after his warranty expires. His treatment here will cause others to be reluctant to ask questions, and diminish the usefulness of the forum.
I have a 2016 Z51 TR Vert....I do NOT get those black specs on my backside....and I drive AGGRESSIVELY...Like some have said it could be a tuning problem and if your dealer won't address it I would call GM and see what they say. Good Luck
I have a VY and although I do not put many miles, mine does not have this. Perhaps could you also put a picture of your exhaust before you wash it off to see if there is also soot? What mode do you drive? Are the valves always open and do you have a Range to keep it in V8 mode? Wondering if it is coming from exhaust rather than the tires.
It's not the exhaust from your car doing this. It's driving over dirty roads. Even pavement that appears relatively clean is not unless it's shortly after a soaking rain storm.
What ever is on the road surface gets picked up by the moving air mass created by your car, and sucked into the low pressure zone which happens to be the rear of the car. Sometimes, it's dirt, sometimes it's tar or oily residue on the pavement.
Now this is a truly dirty back end of a C7. Not very proud of it in the least as this is my DD. Due to a bout of bronchitis, rainy weekends, cold and windy weekends, and other chores that were more pressing, I have not been able to wash the road salt and brine off my 2015 pride and joy SG since the first of January. Just keeping the windows clean is a chore. One weekend I parked my car outside the garage to let God have a go at cleaning it with rain water. This weekend is a "can't wash it this weekend too", I am tempted to try the Touch less car wash at Rushco when I fill up next Wednesday. I will carry some towels with me to dry if the touch less really works.
2 things, I am grateful for is the rain and snow we have been getting In the NC area ending the drought during the past 4 weeks and the SG does a decent job of hiding road grime. CF not so much.
I had what appeared to be the same phenomenon with my '05 coupe and now again with my '15 coupe. I say "appeared to be" because I can't tell via photos whether or not your spots have the same composition as the ones I had / have but they certainly look the same. I've always considered the "spots" to be grime from the air, road, and exhaust that gets drawn to the rear fascia (especially at speed) due to that area being a low pressure zone. Truthfully, I have to wipe down the rear fascia after every drive if I want to keep it free of grime. On another note, my exhaust tips do the same thing. If I want to keep them devoid of any black deposits whatsoever, I have to wipe them down after nearly every drive. (Come to think of it, the same applies to the wheels.) I'm 100% convinced that none of this is due to malfunction and am not concerned about it. YMMV.
Lol your car is not a lemon... if your driving with the exhaust on sport of track mode it lets out a lot more soot then when driving in tour mode because the flaps are open. Get a damp rag clean it off and stop crying about it. If you really regret buying the car because of this issue sell it. I doubt GM will take it back because you are to lazy to clean it once in a while lol.
I keep my exhaust in track mode and have never gotten black carbonaceous spots on the back of my GS.
Oil overfill maybe, since the OP's car is blowing smoke out the exhaust?
But frankly I think it's normal road soot. Even though the OP "lives in a nice area."
02-02-2017, 11:19 PM
Those rascals will rust up anytime the car is washed. I bet GM used cheap metal when they made the rotors for my cars.
