This issue could be caused by stuck oil control rings that can get clogged up over time.
I've been thinking about the above, quite a bit. Before I retired there was a BMW (very popular) engine that also used low drag piston rings. The M54 engine which was available in several displacements. This engine was the ultimate candidate for stuck (read clogged up) oil control rings/ring lands. This would start a domino effect of consumption, high crankcase oil vapor. Which led to more goo on the rings and then even more vapor. All the while with consumption numbers rising on this merry go round ride.
Liqui Moly actually produced an oil that specifically fought stuck/stuck oil control rings. Leichtlauf 5W-40. Once the rings were cleaned, use of this product (either proactively or as a follow on after cleaning) prevented the buildup creating the single biggest contributor to oil consumption: Stuck/fouled oil control rings. Some of the cars in my bays would consume a quart in 500-600 miles! Fouled plugs (check engine light) and poisoned catalytic converters were the result. Cleaning with chemicals (for the worst ones) and habitual frequent oil changes as follow on would most often solve or very significantly reduce the oil consumption.
The Asian product is new to me (BMW/European car tech all my life) albeit, modern pistons and piston ring design are the same in this CAFE governed world. Less ring drag equals higher MPG. Unfortunately many powertrain engineers design for a perfect world whereas everyone uses the correct oil, maintains the vehicle 100%, drives perfect drive cycles and always gets the engine oil warm on every drive. Reality is often NOT what I've just described.
I do still maintain an interest in my field, to that end here's but a small clip of the Telly engine 3.8L (G6DN) being torn down by one of my favorite dismantlers. If you want to know what the inside of your engine looks like; watch this. Especially poignant is his message starting @ 27 minutes.
You can see the hydraulic lifters and valvetrain at/about the 13 minute mark.
I must say that in general I'm impressed with the timing gear. Decent sized chain with good tensioning rails and tensioners. Having seen more than my fair share of lighter designs of late; all in the name of better economy, that ultimately fail and/or are problematic.
I'm unsure if the other flavor of the Liqui Moly Leichtlauf 5W-30 is safe for our cars? Since I'm no longer in business, I'm not really in touch with the Engineering department over at L-M. I may just try to reach out to my old contacts about the detergent-ability of the above 5-30 and use in the 3.8L Telly engine?
I must caution that GENTLE cleaning over time and not magical "Mechanic in a can" solutions are best. Real heavy-duty chemicals that work quickly often have additional consequences that often are undesirable.
As a generality the right oil, changed at active intervals (5-7,500 IMO) are most usually the ticket to engine and piston ring health. The old adage of; "A ounce of prevention, is worth a pound of cure." is applicable here!
Here's the Wiki page on our engines: Scroll down a little past halfway to the G6DN area. I was surprised (not shocked) to learn that it's an Atkinson cycle type of engine.
en.wikipedia.org
Cheers.
