Quote:
Originally Posted by Elite Engineering
The GM factory cleanside separator (CSS) is a pretty good functioning unit. Probably the best to date anyway.
For this reason our cleanside separator (CSS) is NOT required unless your running the car hard. It returns the trapped oil to the crankcase which is safe on the cleanside only. The foul/dirty side is where all of the damaging compounds are part of the vapors and those can NEVER be returned to the crankcase.
So, GM has addressed the point of entry that contributes the least to the intake valve coking and other issues, but they are making progress. It is impossible to deal with the foul/dirty side of the PCV without an external separation device, and those all need to be emptied at least every 5k miles with a large enough one. GM nor any other automaker will make a change that the average "soccer Mom" owner has to do this.
On the LGX 3.6V6 GM has DELETED the positive function of the PCV system in an effort to slow down coking, which it has helped some, but in trade leaves the contaminants to accumulate in the crankcase now greatly increasing internal wear and shortening engine life. A trade off they figure will get the owners past the warranty period before there are noticeable serious issues. NOT a good trade off IMHO.
Here are LGX valves at 13k miles:
As you can see, the deposits are not as pronounced on the valve itself as the LGX and LLT with similar miles, but the deposits are on the stem where they are drawn into the softer guide wearing them out. Look close and see how hard and baked light colored these are from the increased heat.
I hope this helps!
 |
Thanks for the additional detail about the LGX.
Have you determined exactly how GM is managing the foul side of the PCV system without an externally accessible connection to the vacuum of the IM?
Isn't there an EPA or CARB requirement for
Positive Crankcase Ventilation? If they are drawing in fresh air on the Clean Side, there must be vacuum on the foul side to create that flow.