NOACK ? and your opinion

[beanoil]

2010 Equinox DI. Currently at 6000 miles. Changed the FF at 500 to Schaeffer 7k. Changed again at 3k to Schaeffer 9k, and had planned on 6k OCI going forward. The research I've done here, Noria, and other boards are all trending toward an oil with low NOACK numbers for DI engines to minimize valve deposits. So, what do you say? There are several with really low, single digit NOACK's, like Valvoline MaxLife Syn, AmSoil ATM, Mobil High Mileage. With Schaeffer 9k being in the double digits, is there an advantage to lower NOACK numbers, and should I consider a switch? Or stay the course with an oil that is known and accepted to be a good performer and just roll on? Schaeffer is reasonably priced, practically the same as Mobil High Mileage, while Valvo and AmSoil are slightly more. Where is my biggest bang for the buck in this DI engine?

 

[rclint]

I may show my ignorance here, however I will give you something to think about.. Whenever you have a specific problem with a engine component many people will critique a way around it be it in theory or in real life, and they will show carts or indulge in oil manufacture charts that are blow out of proportion to find a fix.. When looking for a low NOACK oil keep in mind the numbers, and research NOACK to find what the differences really mean..

 

[Jehartley]

I think a saw a used oil analysis here awhile back with Penn Platinum in a DI engine from GM. Seemed to hold up really well, and it's Novack% is on the high end.

 

[mechanicx]

I think Pennzoil stated that it was the type and amount of VI modifiers that were important in limiting depostits in a DI engine. But an oil with the same grade and less VIM tends to have a lower NOACK.

 

[ARCOgraphite]

Given the oil is fogged into a mist in the crankcase - the PCV would be the #1 spot to reduce oil influx into the intake port. Do the DI use PCV?

 

[Gary Allan]

Without altering the PCV system (not a likely thing to occur with something too new), and the equally as unlikely notion of using something more towards a monograde (again due to fear factors) like ACD w/6.x volatility, you just have to live with it.

Whatever you do, don't change it too often to introduce even more stuff to be volatilized and foul the intake and valves.

 

[shpankey]

Originally Posted By: ARCOgraphite
Given the oil is fogged into a mist in the crankcase - the PCV would be the #1 spot to reduce oil influx into the intake port. Do the DI use PCV?
Unfortunately, yes. And on most of them, they are very poor. Mazda has long rumored to have a PCV upgrade coming for all us Mazdaspeed guys which is supposed to help in this area.

Or you could do something like a bypass or whatever. I've seen some people route it to their exhaust at a certain angle that creates a suction and excavate it out the tailpipe.

There's also the EGR issue... some guys on the mazdaspeed forums think this has more to do with the intake valve deposits that even the PCV and therefore they block the EGR completely off. This throws a CEL, but if you have a Cobb AP or CP-e Standback, you can delete the code forever apparently.

Oh and to the guy who posted about PP above... a used oil analysis is not going to show if a particular oil gave you more or less intake valve deposits. At least I don't think so.

 

[Gary Allan]

Quote:
Or you could do something like a bypass or whatever.


You can alter them with deceleration chambers to reduce any oil in the flow. It works ..usually. A catch can would be a good way to survey how much is going out the tube. Whatever is in the can, that's what would be on the intake and valves.

Quote:
I've seen some people route it to their exhaust at a certain angle that creates a suction and excavate it out the tailpipe.


Venturi extractors. Developed by Grumpy Jenkins in (iirc) the early 70's and later adopted by GM for OEM. Abandoned due to tighter emissions and cat protection. Also illegal. If you go commando, vent generously or you'll suck in seals.

 

[Trex101]

Low noack% number normally indicate high viscosity base oil with min VII, you will most likely find those in 10w30 grade oil then 0w30 or 5w40.

I would choose ATM 10w30 which i think have the best noack% around.