When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Discoloration of black exhaust tips after a track day
Has anyone seen anything like that? My outside exhaust tips turned greenish brown on the inside. I think that's because the exhaust outlet going to the outside tips goes at an angle to a tip, and the gas blasts the side of the tip. Did anyone notice a similar issue?
Has anyone seen anything like that? My outside exhaust tips turned greenish brown on the inside. I think that's because the exhaust outlet going to the outside tips goes at an angle to a tip, and the gas blasts the side of the tip. Did anyone notice a similar issue?
Discoloration is normal. Tan to light tan is a good hot clean buildup. Black is too rich and the green you describe is a little odd. May be due to fuel or additives you are using?, or something unusual getting into combustion chamber? Suggest you check with your shop on that.
I did not mean the brownish powdery thing on the inside of the tips. I meant the black paint on the tips turning green. Here is a photo - note how the edge of the left tip is greenish on one side while the right tip is black as it was before.
On the left tip assembly I do see greenish discoloration on the outer most lower lip portion. I also see what appears to be tip greenish tempering on the heat shielding (or reflection?) below the right assembly. The tips are likely anodized, not painted. They do discolor under the higher temp ranges on the track. Kind of like a header can discolor. Mine are no longer gloss black either. The green may just be a function of the particular anodizing run on those tip parts, but the shielding discoloration is unusual, otherwise inside the pipes looks like a reasonable burn, though a lighter tan from a hotter/leaner combustion post cat is more track common. Has this engine been tuned or modded? Assuming no, you might ask your dealer, you don't have to say anything about where it happened, just that you were running it fairly hard. Dealers vary on how they handle the tracking stuff and warrantees.
Edit: I don't see any shield under mine just the top and sides, so not sure what is green under yours.
This will happen when you run your car hard and at higher speeds. The carbon build up is not due to the high heat. This is normal in the 997 and 991 turbos. Once you drive the car at your normal pace around town your tips will return to carbon black again. This is totally normal for a track day or if you are pushing the car and breaking the law driving on the street. Nothing to worry about.
‘Blew a turbo 1 1/2 ago , oil lleak then turn exhaust into a blow torch. Happened at Homestead
I almost did it to my GT3 but caught it in time. I noticed a tad of oil spray on rear bumper before the first session at Laguna few weeks ago. I check under the car - everything looks dry. So just to be sure I reached above the engine cover tray, and there was a pool of oil in the tray. In GT3 the tray almost touches the headers, so the oil would have sloshed around and onto the headers if I drove it on the track. Lucky catch.
On the left tip assembly I do see greenish discoloration on the outer most lower lip portion. I also see what appears to be tip greenish tempering on the heat shielding (or reflection?) below the right assembly. The tips are likely anodized, not painted. They do discolor under the higher temp ranges on the track. Kind of like a header can discolor. Mine are no longer gloss black either. The green may just be a function of the particular anodizing run on those tip parts, but the shielding discoloration is unusual, otherwise inside the pipes looks like a reasonable burn, though a lighter tan from a hotter/leaner combustion post cat is more track common. Has this engine been tuned or modded? Assuming no, you might ask your dealer, you don't have to say anything about where it happened, just that you were running it fairly hard. Dealers vary on how they handle the tracking stuff and warrantees.
Edit: I don't see any shield under mine just the top and sides, so not sure what is green under yours.
I think what you are referring to (discolored bit under the tip) is the actual exhaust muffler. It's inconel, so it turns blue at relatively modest temperatures.
08-05-2018, 12:47 AM
Discoloration of black exhaust tips after a track day
