I have significant carbon deposits on my 2008 HHR-SS tailpipe ever since new. These deposits are slightly greasy, therefore oil related in my opinion and not from a rich fuel mixture. I have completely cleaned these deposits several times and they keep reforming. An expert mechanic I know suspected that the turbo may be sucking oil vapor from the crankcase due to a leaky valve somewhere. Of course the Chevy dealer where I bought the car says "that's normal" and there is nothing wrong.... I'm worried about long term effects to engine performance. Anyone else have this same situation? Diagnosis and solutions??

 

Everyone has this black soot on their HHR SS. It is a natural occurance and by product for the Direct Injection engine. Even the Cadillac CTS and Camaro with the 3.6 DI engine gets this same soot.

You expert needs to read up on DI engines as they will be in his shop soon and they do have some things that he will need to address differently like Fuel pressures over 2000 PSI. DI will be industry wide in the near future.

The dealer gave you the correct answer and did not lie to you.

All you can do is take some fine steel wool and clean it off once in a while.

FYI don't feel bad most of the rest of us thought something was wrong till we learned about the DI engines doing this. It is a faily new thing for not only GM but the auto industry.

 

my truck has black all n the tip.. i can wipe it out with a rag.. then again it also runs so rich if u take a wiff while shes runnin, you almost get a sick feeling n eyes burnn wonder why a new car would do it so bad though?

 

I agree with Hyperv6 as I have know about this for some time as well. It is something you just have to deal with...

I use a SOS cleaning pad to scrub the pipe out after every wash, but at 38K now it is getting kind of pitted beyond polishing out. I guess I am not so hung up on having it perfectly shiny anymore either! I have thought about eventually replacing it with a stainless steel tip, as I don't think that would pit like this OEM chrome one does.

 

The OE is polished stainless that is why it stays as good as it is. If it were chrome it would be even more pitted. Your entire exhaust is stainless and will last the life of the car.

My Pontiac is 25 years old this year and still has the original OE stainless on it.

Might want to go to fine steel wool as it will not scratch as much cleaning. Never dull also cleans well.

 

I knew all the piping was stainless, but the tip sure looked chrome plated. I'll have to look closer at it next time...

Yes, exhaust systems sure do last a long time now. 226K mi. on my '98 Tahoe and that is all original. I almost wish it would go out so I'd have a reason to put a Borla or anoth HP system on it!

 

It's normal. No worry

 

mine does it too... and I run all freeway so it's not build up. Time for a new pipes!