[bruker]

Has anyone else here noticed a heavy deposit of soot or carbon on the tail pipes? I have a `10 V6 and it make me wonder if the engine is burning too rich. Anyone?

 

[RNOX]

I have a Chrome tailpipe. Seems to have a little tar like sustance at the bottom of the tailpipe,

 

[RnB]

Ours is like this also. Its the richest running new car I've owned. Pain in the butt to keep clean.

 

[RIT333]

Ours is like this also. Its the richest running new car I've owned. Pain in the butt to keep clean.

So, it's a pain in the butt cleaning your tailpipe ? May want to consider some Preparation H.

:drunk:

 

[grometsc]

Has anyone else here noticed a heavy deposit of soot or carbon on the tail pipes? I have a `10 V6 and it make me wonder if the engine is burning too rich. Anyone?

Normal for gDI to have this

http://bznotes.wordpress.com/2007/01/14/soot-emissions-from-gasoline-direct-injectin-gdi-engines/


Quote from article about HFV6's...not posting the entire stuff (would make EVERYONE panic as they do on this forum over little things LOL)

Haider, GM’s V6 assistant chief engineer, explained how GM has designed its DI engines to combat carbon buildup: “We maintain great engine function and performance in our all our DI engines through an optimization strategy with our valve events,” he said. “Our intake-cam timing, injector targeting and timing of the injection events are optimized to avoid direct fuel contact on the intake valves. This strategy keeps smoke and soot formation to an absolute minimum, which in turn prevents excessive deposit formation.”

 

[bigb12359]

hi ,

Subject: Black Smoke On Cold Start



Models: 2009-2012 Buick Enclave

2009-2012 Buick Lacrosse

2009-2012 Cadillac CTS SRX STS

2010-2012 Chevrolet Camaro

2010-2012 Chevrolet Equinox

2009-2012 Chevrolet Malibu

2009-2012 Chevrolet Traverse

2009-2012 GMC Acadia

2010-2012 GMC Terrain

2009-2010 Saturn Outlook

2009-2010 Saturn Vue

with 3.0L LF1, LFW and 3.6L LLT, LFX engines only



--------------------------------------------------------------------------------

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:



Concern:
BLACK SMOKE ON START UP ONLY.

With the introduction of direct fuel injection systems, GM has revised the cold start control system to reduce cold start emissions. Quicker catalytic converter heating helps meet the ever changing emission requirements and improve fuel economy.

Recommendation/Instructions:

A dual-pulse injection strategy is utilized during engine cold start to reduce the time required to bring the catalytic converter up to operating temperature. This split injection strategy lasts for about 60 seconds on cold start.

This process will cause the customer to see increased black smoke or soot during cold start and should be considered normal.

This cold start strategy is enabled upon start up after the engine has soaked for sufficient time such that the catalytic converter requires rapid reactivation.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

:beer: