JettaRed

iTrader: (1)

I mostly understand what you said.

CaliBenzDriver

Thank you Juan for bringing this brilliant PhD research to our awarness.


Here is what the conclusions say....

1. LS.PI needs specific conditions
2. a thin oil vapor droplets
3. "highly elevated" intake temps
4. extreme coolant temp

Do you happen to recognize that whole picture ???
It's exactly MOD-0 stock conditions.


For MOD'ers... this means we have some level immunity to burnt oil issues.


> IOW WHAT IS IT:
This is dieseling ie. self-igniting the lubricant that is said to have escaped through rings (intake as well!)

The remaining carbon is thought as a self-sealing soft carbon sort of lubricant. So the "approved oils" are designed to be burned in specific ways. Meaning the engine is expected to ingest oil that must be formulated for combustion.

Self-ignition has been around since day-1 of diesel tractors (circa 1900) with manually heated igniter.

when self-igniting temps are avoided...
guess what happen when MOD-2 engines don't consume oil.... Problem Cancelled!

​​​​​​Cooled pistons are good!


++++ WHATS CAUSES LS.PI ...
The stock provides "Approved" burnable lubricant:
+ Thin vaporized oil
+ pistons hot spots
+ Extreme temps
= setup for pre-ignition

> How to prevent LSPI:
Cancel every factors with effective piston cooling and SP rated oil with reduced calcium, low poly-unsaturated fats


+++++ The funny thing....
Novel engine issues have developed related to lubricants, cylinder scoring... have become popular. what if limited oiling what the root cause??

> Wet vs. dry rings:
The oil gets so hot in contact of extremely heated pistons, it flash vaporizes into gaseous form.

Rings have no chance to "wipe a vapor " ie. contain pressure on a dry ring is compromised.



+++++ FORGOTTEN PATHWAY... PCV
We all got focused on the oil migrating around pistons however the REALITY IS ELSEWHERE... PCV!

Quarts of the vaporized oil travels through intake plenum to get combusted, not so much through pistons rings.

> How Do I Know This???
-- When my hot pistons used to vaporizes quarts of oil on MOD-0 + MOD-1, I smell condensate oil from the open NA intake on MOD-1.

-- When oil doesn't vaporize into intake no consumption on MOD-2.1 or above.


We have cooling options not to struggle with engineered LS.PI crisis.

CaliBenzDriver

Does your M157 also feature an engine heat exchanger between oil + coolant or only a front oil cooler ?

The low RPM slow traffic heat suffers from pre-existing extreme heat while driving.

This is a sort of heatsoak except the engine is idling.
Engine shows up hot and stays hot with no way to cool regardless of fan speed.
The heat moving pumps are tied to RPM.

kevm14

It has both.

CaliBenzDriver

M157 OIL cooling uses a better system :

• regular coolant heat exchanger
• plus oil tstat for quick warmups
• and a serious oil cooler up front

More oil heat can be removed directly when oil is circulated well.
Oil temps may not mirror that of other engines without cooler.

Everything else applies including limited spray efficiency below 3000.Rpm.

JettaRed

iTrader: (1)

I wanna be the first to share this. Mobil 1 0W-40 will shear down to a 30 weight in as little as a couple hundred miles!

OldManAndHisCar

I see these pics...My temps are ALWAYS opposite of the images. I am generally 10F higher on top, if I am driving a bit harder 20F higher on top.........only in the AM (and under 90F outdoor temps) are my numbers on the dash equal or lower on the top....should I worry?

CaliBenzDriver

Don't worry about any of the dash coolant IC display. It is meaningless!
The jury is still out validating the oil temp display.

The only thing worthy of consideration are OBD Temps.

If you want to improve heat removal, provide better viscosity or consider JR's latest Pennzoil.
@JettaRed

kevm14

Hotter conditions will drive oil temp past the "fake display coolant temp" so that is normal because your profile suggests you are in FL.

kevm14

Looks like he got his hands on the new API SP formulation. That must be working its way to shelves now. But I already switched to Pennzoil on my S550.

Ultrakla$$ic

Am I seeing this info in this vid correctly that Liquid Moly did terrible in the test??? I use Amsoil but I see alot of Liquid Moly users here. and I have ZERO idea which one of those blends closely represent something like Amsoil much less why the guy never does a video on Amsoil whether good or bad........puzzling.

kevm14

He tested one LiquiMoly oil, 10W-60, which none of us use. And I got a good UOA on Molygen 5W40 anyway. I believe it was still in grade at 5000 miles.

phil34

is molygen 5w40 SP rated?

kevm14

Nope

Ultrakla$$ic

Car is TOTALED j/k

phil34

So should one not use it in direct inject engines?

JettaRed

iTrader: (1)

I've wondered about all of us with DI engines using non-API SP oil (because it didn't exist) for years and thousands of miles. Our engines seem to have survived (or maybe not). Of course, API SP standards were set and oils were made in response to the issues with LSPI. Going forward, I will be using API SP rated oil only. My old stock I will save for my son's 2004 Audi TT (previously mine).

phil34

I have had my 1st DI car for only a few months, 2015 S550. Before I bought it I required an independent inspection and B service done at the dealers expense. The independent shop used 5W40 liqui moly leichtlauf high tech. Guess I will stick with that as it is SP rated with low calcium.

Rickman30

I was using Liquid-Moly 5w-40 Molygen, it tested as a 30w after a very short period, because dastardly weasel dealer service manager and lead tech, said my oil was contaminated with coolant and bearing material. So, I tested under 1k, just to see.

As it would turn out, the test came back "No contamination or abnormal wear" In fact they said this engine has less wear than the average they've recorded for the M276.

But the oil tested 10.6 cSt viscosity @ 100 degrees C, tolerance of a 40 weight oil is 11.6 to 15.3. So, picked up the Mobil 1 API SP the other day. Fingers crossed. Keep us posted on the Pennzoil, as it was a toss up for me as well.

kevm14

My Molygen was 12.31 after 5000 miles (does include one makeup liter). My M157 is still on Molygen until I find something better to run. I highly doubt M1 0W-40 is better.

Rickman30

Wow, Mine wasn't even close to that, wasn't old enough to have used any. Who did you use for testing?

ImolaSix

This has been known for years and was briefly discussed in this thread a few months ago. All engine oil shears over time. Mobil 1 0w40 starts out as a relatively light 40 weight oil. It doesn't take much for it to shear to a 30 weight. Modern turbo DI engines are notorious for accelerating oil viscosity breakdown due to high operating temps and DI fuel dilution.
Car manufacturers take this shear rate into account when testing oil for a given spec. Just because an oil crosses over from a 40 to 30 weight doesn't automatically mean your bearings will score. There's much more to how oil films protect internals than just viscosity. Mobil 1 0w40 is a good oil as a standard fill for most use cases, however if you are tuned and or drive aggressively there are certainly better options.

kevm14

I posted my oil analysis a little while back. I guess some people missed it. I used Blackstone.

Rickman30

That's who I'm using. I guess the DI and higher temps are harder on the oil. I drive like there's a raw egg under the accelerator pedal. I have Drive n Save nanny.

kevm14

Harder than what? I have an E63S. My other car is an S550 with M273....never had an oil analysis on that one.