: 2008 STS 3.6 Black Soot build up in tailpipe



Rushnack
05-29-13, 08:53 PM
Hi everyone, I have a 2008 STS with a 3.6 and 52k on her.. This car is very well cared for and I have noticed since i got is last September that it has a light soot build up in the tail pipes.. The engine gets its oil changes, I havent noticed any performance issues and my daily driving is 25 miles to work each way at hiway speeds.. I dont think its a good sign... Anyone have any thoughts ?? Should I be concerned ??

1BadCadSTS
05-29-13, 09:50 PM
All exhausts will get soot, perfectly normal. No tail pipe stays clean after awhile of driving.

EChas3
05-29-13, 11:27 PM
I agree with 1Bad but, check your oil level regularly. How much does it use?

Rushnack
05-30-13, 12:36 AM
I cant say I agree that all exhaust will get soot.. I have 2 other vehicles and they run great as well and no soot residue at all, thus my concern.. I have had the car since sept, and no oil usage detected..

1BadCadSTS
05-30-13, 07:42 AM
Are they a Tesla and a Prius?


In all seriousness exhaust systems expel carbon from the motor. Depending on how you drive and how good the valves and rings are will determine how much.

Submariner409
05-30-13, 08:05 AM
In all seriousness exhaust systems expel carbon from the motor. Depending on how you drive and how good the valves and rings are will determine how much.

That ^^^, and tailpipe tips will exhibit less soot after a speed run to Florida and back than they will after a slow commute home .........

Black powdery soot is unburnt gasoline/cold exhaust pipes. Black oily or fluffy soot is oil. The 3.6 (??? DI ???) is known for oil pooling in the intake manifold flat - that MIGHT be a reason for your soot - talk to SC2150 up in the newer CTS forums.

caddy virgin
06-02-13, 03:46 PM
Hello this is my first time as a member after finding so much helpful insight i knew i had to join. So thankyou fellow cadillac enthusiaist ,I recently purchased my first caddy for my wife we both love her 2001 sts but she started overheating with 121,000 and after the radiator test the blue water turned green ,So i'm about to drop the engine cradle and replace the bolts and gaskets .My question is in chiltons they say you need to chain the chain to the cam sprokets with tool # j-38822 and four tie wraps but in a posting on the forum on 06/29/2007 headgasket replacement by the book engine removal for a 1998 he says remove chain tensioner and sproket with timing chain remaining inthe chain case did the procedure change from 98 any help would be helpful thank you

jimmbo
06-02-13, 07:59 PM
I think the sooting is a characteristic of combustion under certain operating parameters in a Direct Injection Engine.

EChas3
06-02-13, 09:34 PM
Hello this is my first time as a member after finding so much helpful insight i knew i had to join. So thankyou fellow cadillac enthusiaist ,I recently purchased my first caddy for my wife we both love her 2001 sts but she started overheating with 121,000 and after the radiator test the blue water turned green ,So i'm about to drop the engine cradle and replace the bolts and gaskets .My question is in chiltons they say you need to chain the chain to the cam sprokets with tool # j-38822 and four tie wraps but in a posting on the forum on 06/29/2007 headgasket replacement by the book engine removal for a 1998 he says remove chain tensioner and sproket with timing chain remaining inthe chain case did the procedure change from 98 any help would be helpful thank you

CV - Get thee to the Northstar Technical forum. Chilton's is not enough. You need an expert & Timecerts.

Besides, you've posted in the 2005 & up STS forum. Our Northstars are second generation RWD & AWD and no longer have the old problems. I feel for ya; my wife had a '98 Seville STS. Beautiful car but the FWD never could handle like a world-class car and finally had HG & other issues.