Why ? DI engines have just fresh air going by the valves. DI means DIRECTED INJECTION into the combustion cylinder just like a Diesel. With nothing but air going by the valves there is no reason to clean the valves since the fuel is injected at the cylinder instead the valve.

 

Understand...

The GM 3.6L engine has an internal EGR system, unlike the Audi DI engines. I read up on the GM version and sounds nicer than other manufacturers of DI engines.

What about the PCV ? Doesn't some oil vapors go back into the intake engine or not ? What what I know they do and if you have an oil with a high NOACK, you are getting that "oil" or burnoff back into the intake.

The HUGE problem is we can't clean the intake valves as easy as before. The DI injector is below the valves and no fuel system cleaner will work, etc..

So, I was just thinking that if you're using an oil with an extremely low NOACK, you should be helping the engine stay as clean as possible.

I'm far from a motor-head so that's why I'm trying to educate myself on these new engines....

 

Didnt I Just see this question posted somewhere-- where Penzoil engineers answered the question?

 

Didnt I Just see this question posted somewhere-- where Penzoil engineers answered the question?

Here we are: http://www.enclaveforum.net/index.php?topic=6900.0

 

OK, here is what Pennzoil said, "Oil volatility is not a significant factor for inlet valve deposits in a direct injection gasoline engine. The significant factor is viscosity modifier type and concentration, so using fully synthetic narrow span viscosity grades such as 5W-20 is beneficial. In North America, there is no specification calling for NOACK of less than 10%. The most important thing for DI engines is engine design, to better prevent deposits on ITV’s (In Take Valves), since there is no fuel wash as in PFI (Port Fuel Injection) engines.

Unfortunately, offering a guarantee against deposits would be tough since so many other variables could impact the outcome."

In a sense this does not tell me squat. If I understand what they said correctly then a 10W30 would be better then a 5W30 or a 0W30. A straight 30W would be the best for this one single factor. Or, we could all try Redline for they have not viscosity modifies.

Some may know how to determine the amount of viscosity modifiers in a specific oil but I sure do not and Pennzoil was not forth coming on whether they have a lot or a little. I assume they have a lot viscosity modifiers, or only at best equal to other brands, or they would have made a point of saying the contrary. However we do not Pennzoil Ultra has turned in better UOA results than I think any other PCMO that we have seen so far and way better then Mobil1 BUT, UOAs do not help us see what is building up on the valves.

I have given though of adding a catch can for the PCV but have not look at the set up to see if it is possible.

We do have a member who has over 100K on his 3.6 and it is still going strong but I believe he is doing oil changes when the OLM hits 50% - do I remember that correctly?

 

We do have a member who has over 100K on his 3.6 and it is still going strong but I believe he is doing oil changes when the OLM hits 50% - do I remember that correctly?

That many for the DI engine on a Lambda?

 

I would agree on the SAE30 weight IF you're climate will allow it.

I know for sure Amsoil ACD uses no VI Improvers along with their Marine 10w-30. I would also assume that the NON-XL 30 weights would contain such a small amount of VI Improvers.

Speaking of NOACK, Redline and Amsoil have some of the lowest around.

When my Enclave gets delivered next month, I'm leaning towards using Amsoil HDD 5w-30 diesel oil.