2016 RS LGX - Carbon Build Up on Exhaust Tips

kraut1971 · 06-13-2019, 03:04 PM

I purchased a used 2016 RS / LGX V6 with 50,000 miles last November. I recently upgraded to the MRT V2 exhaust system with stainless steel tips. I'm shocked at how often I need to wipe the exhaust tips to keep them clean. The OEM exhaust was also stainless steel, but was virtually turned black with carbon build up (apparently the previous owner didn't clean them like I do).

Here's my question: Should I be concerned at the amount of carbon build up that I'm noticing or is this normal with the LGX engine? It's easy enough to wipe up, but I'm wondering if this may be a symptom of a larger undiagnosed issue.

I previously owned a 2013 LFX V6 and had a catch-can installed right away. Never noticed any carbon build up with that engine so I'm thinking that may be a simple first step to turn off what I'm noticing on my 6thGen.

I respect the cross-section of experience and know-how this forum provides so any input would be greatly appreciated!

HCI2000SS · 06-13-2019, 04:42 PM

My 2018 RS V6 does the same thing. I'm told it's completely normal on these cars.

BTW how do you like that MRT V2 exhaust? I'm not to far from them, and have dealt with them many times over the years. Scott and the guys make good quality exhaust s

cellsafemode · 06-13-2019, 05:25 PM

Check your throttle body. If it's all oily and caked with soot, then a catch can will help.

If not, then a catch can will not be catching anything because there's nothing to catch.

Either way, you can expect that even with a perfect catch can setup. I would not jump to the conclusion that you're burning more oil with a GDI car vs older types of gasoline injection cars. GDI is more efficient so more of the fuel is burnt in the engine and not in the catalytic converter, so that changes your exhaust wastes, on top of the dual convertor setup that ensures any remaining unburnt fuel is burnt... end result is more fuel is burnt per volume that reaches your exhaust tips than non-GDI cars == more soot (when we're talking about the same fuel)

DriftNDraft · 06-13-2019, 11:08 PM

I have NPP exhaust on my 2018 V6 and leave my car in sport mode 90 per cent of the time. After 9,000 miles the sport outboard exhaust tips are much blacker inside than the inboard tour mode tips. I'm pretty sure it's just the way the LGX is.

protovack · 06-14-2019, 12:10 AM

It's normal on all vehicles, you just see it more because its a big exhaust tip that is polished stainless.

kraut1971 · 06-14-2019, 07:52 AM

Quote:

Originally Posted by DriftNDraft

I have NPP exhaust on my 2018 V6 and leave my car in sport mode 90 per cent of the time. After 9,000 miles the sport outboard exhaust tips are much blacker inside than the inboard tour mode tips. I'm pretty sure it's just the way the LGX is.

Excellent perspective! I'm always in Sport Mode so that would coincide with your point. I may drop to touring for a week or two and see if that makes any difference. Thanks for responding!

kraut1971 · 06-14-2019, 08:14 AM

Quote:

Originally Posted by HCI2000SS

My 2018 RS V6 does the same thing. I'm told it's completely normal on these cars.

BTW how do you like that MRT V2 exhaust? I'm not to far from them, and have dealt with them many times over the years. Scott and the guys make good quality exhaust s

I'm relieved to hear so many people calling this carbon build up "normal". I was concerned that my rings may have gone bad or some other major issue!

Regarding my MRT V2s: I LOVE THEM! I had the same set up on my 2013 and got compliments all the time. [I feel my 2013 sounded better, but I also put on a CAI Cold Air Intake which added a deep growl under the hood which also contributed to it's awesome sound. Apparently, you can't add a cold air intake onto the 6thGens without also getting a tune so I'm not planning on that mod].

Without a doubt, I can say this: Since adding the MRTs, I go WOT all the time just because I love to hear the exhaust note, which may very well be the #1 contributor to my carbon build up concern. As long as I don't have any major mechanical issues, I'm fine with cleaning the stainless steel a couple of times a month!

cellsafemode · 06-14-2019, 09:18 AM

dynomat (rather, use a better off-brand alt - 80mm thick) the hell out of your trunk. Just remove the fabric walls and floor and unscrew the styrofoam center and amp and fuse box and cover every exposed piece of metal in sound deadening.

With the MRT, you will be thankful you did that sooner than waiting a couple years to do it.

(i've had the mrt v1 for a couple years now).

kraut1971 · 06-15-2019, 08:52 AM

Quote:

Originally Posted by cellsafemode

dynomat (rather, use a better off-brand alt - 80mm thick) the hell out of your trunk. Just remove the fabric walls and floor and unscrew the styrofoam center and amp and fuse box and cover every exposed piece of metal in sound deadening.

With the MRT, you will be thankful you did that sooner than waiting a couple years to do it.

(i've had the mrt v1 for a couple years now).

dpevans · 06-24-2019, 09:46 AM

Even my wife's Camry tips look black. I wipe with every wash and polish with Flitz every couple months.

06-13-2019, 03:04 PM	#1
kraut1971 BITCHN Camaro Drives: SOLD! Back in the looking zone... Join Date: Feb 2015 Location: Saline, MI Posts: 248 View My Garage	2016 RS LGX - Carbon Build Up on Exhaust Tips I purchased a used 2016 RS / LGX V6 with 50,000 miles last November. I recently upgraded to the MRT V2 exhaust system with stainless steel tips. I'm shocked at how often I need to wipe the exhaust tips to keep them clean. The OEM exhaust was also stainless steel, but was virtually turned black with carbon build up (apparently the previous owner didn't clean them like I do). Here's my question: Should I be concerned at the amount of carbon build up that I'm noticing or is this normal with the LGX engine? It's easy enough to wipe up, but I'm wondering if this may be a symptom of a larger undiagnosed issue. I previously owned a 2013 LFX V6 and had a catch-can installed right away. Never noticed any carbon build up with that engine so I'm thinking that may be a simple first step to turn off what I'm noticing on my 6thGen. I respect the cross-section of experience and know-how this forum provides so any input would be greatly appreciated! __________________ BITCHN

06-13-2019, 04:42 PM	#2
HCI2000SS Drives: 2018 Camaro V6/RS Join Date: Nov 2018 Location: MI Posts: 1,596	My 2018 RS V6 does the same thing. I'm told it's completely normal on these cars. BTW how do you like that MRT V2 exhaust? I'm not to far from them, and have dealt with them many times over the years. Scott and the guys make good quality exhaust s

06-13-2019, 05:25 PM	#3
cellsafemode Drives: 2016 Camaro 1LT Join Date: Jan 2016 Location: California Posts: 3,491	Check your throttle body. If it's all oily and caked with soot, then a catch can will help. If not, then a catch can will not be catching anything because there's nothing to catch. Either way, you can expect that even with a perfect catch can setup. I would not jump to the conclusion that you're burning more oil with a GDI car vs older types of gasoline injection cars. GDI is more efficient so more of the fuel is burnt in the engine and not in the catalytic converter, so that changes your exhaust wastes, on top of the dual convertor setup that ensures any remaining unburnt fuel is burnt... end result is more fuel is burnt per volume that reaches your exhaust tips than non-GDI cars == more soot (when we're talking about the same fuel)

06-13-2019, 11:08 PM	#4
DriftNDraft Drives: 2020 1SS 1LE M6 was 2018 V6 RS A8 Join Date: May 2018 Location: Minnesota Posts: 59	I have NPP exhaust on my 2018 V6 and leave my car in sport mode 90 per cent of the time. After 9,000 miles the sport outboard exhaust tips are much blacker inside than the inboard tour mode tips. I'm pretty sure it's just the way the LGX is.

06-14-2019, 12:10 AM	#5
protovack Drives: 2019 2LT 2.0T M6 Riverside Blue Join Date: Jan 2018 Location: WA Posts: 847	It's normal on all vehicles, you just see it more because its a big exhaust tip that is polished stainless.

06-14-2019, 09:18 AM	#8
cellsafemode Drives: 2016 Camaro 1LT Join Date: Jan 2016 Location: California Posts: 3,491	dynomat (rather, use a better off-brand alt - 80mm thick) the hell out of your trunk. Just remove the fabric walls and floor and unscrew the styrofoam center and amp and fuse box and cover every exposed piece of metal in sound deadening. With the MRT, you will be thankful you did that sooner than waiting a couple years to do it. (i've had the mrt v1 for a couple years now).

06-24-2019, 09:46 AM	#10
dpevans Drives: 2024 Riverside Blue 2SS 1LE Join Date: Mar 2016 Location: Fort Wayne, IN Posts: 1,206	Even my wife's Camry tips look black. I wipe with every wash and polish with Flitz every couple months.

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