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Under normal conditions M276; M278; M157 do NOT see engine damage... define normal for twin-turbo engines
Engines that get pushed to extremes may exceed stock limits to encounter casual issues as follows...
the issue I'm told is the factory press didn't push in the sleeve correctly and causes a leak. Not all M157 are affected, but the ones that used that press were
Nothing to do with oil. This is a machine tool out of tollerance issue, and a known problem. Changing oil types won’t help, disconnecting solenoid won’t help. Focusing on rare cases, such as this, reported online skews our perception of just how widespread these issues are. They affect a VERY SMALL percentage of actual production.
Cali, you are a posting machine and we love you for it,, But lets try keep the word salads focused on the truth
Last edited by crconsulting; May 26, 2025 at 07:19 PM.
Nothing to do with oil.
This is a machine tool out of tollerance issue and a known problem.
Changing oil types won’t help,
disconnecting solenoid won’t help.
Focusing on rare cases, such as this, reported online skews our perception of just how widespread these issues are.
They affect a VERY SMALL percentage of actual production.
Cali, you are a posting machine and we love you for it,, But lets try keep the word salads focused on the truth
"no cabbage salade"...
can we stick with honest pragmatism, ja ?
MB has extended warranty coverage still partly available for new engine rebuild $$$$$ all m278 + m157 misfire over 5yrs production
MB warranty speaks of valve guides wearing out... prematurely between 60k to 100k.Mi.
prematurely worned out guides cause valve wear to leak
CRC contribution : is this unrelated or misleading ??
Therefore drafty misfires out of warranty is most likely terminal coils & injectors useless.
Leaky cylinders :
bad heads (dry guides + valves seats)
bad block (wasted bore)
bad rings (carboned)
Better oiling would indeed help valve guides for cheap. Something interesting to be said about intake and exhaust valve guides: oil goes the opposite direction. Exhaust stems do not get sucked dry... then how do they get dried: vaporized oil.
I've read MY#19 is affected with now perfected soft valve guide damage that waste valve seat (ref. to post?) Less 100kMi.
Last edited by CaliBenzDriver; May 27, 2025 at 03:35 AM.
Better oiling would indeed help valve guides for cheap. Something interesting to be said about intake and exhaust valve guides: oil goes the opposite direction. Exhaust stems do not get sucked dry... then how do they get dried: vaporized oil. .
WRONG……
More oil in the valve guides would create more carbon on the backside of valves, if anything. You couldn't possibly deliver enough oil to get past the valve guides seals to make a difference in a normal operating environment. You realize there are valve guide seals right?
Hope you understand how the VALVE SEAT CONCENTRICITY ISSUES related to machining (or materials) of those seats LED TO VALVE GUIDE WEAR. This is what cased the misfire in the cylinder that destroyed it. See pic below, now imagine the side forces generated by this misalignment. Abnormal guide wear is a side effect of this misalignment.
NO INCREASE IN OIL PRESSURE WILL CHANGE THE CONDITION THAT LED TO THOSE FAILURES
Cali serious question. I know you’re a computer guy but,
Have you ever taken apart an engine?
(I think it’s a good idea for every DIY to take apart at least one engine to understand some basics)
M278/M276 valve guide seals,
This is a valve seat concentricity gauge manufactured by Sioux used to measure runout in the seat.
Last edited by crconsulting; May 27, 2025 at 11:45 AM.
WRONG……
More oil in the valve guides would create more carbon on the backside of valves, if anything. You couldn't possibly deliver enough oil to get past the valve guides seals to make a difference in a normal operating environment. You realize there are valve guide seals right?
Hope you understand how the VALVE SEAT CONCENTRICITY ISSUES related to machining (or materials) of those seats LED TO VALVE GUIDE WEAR. This is what cased the misfire in the cylinder that destroyed it. See pic below, now imagine the side forces generated by this misalignment. Abnormal guide wear is a side effect of this misalignment.
NO INCREASE IN OIL PRESSURE WILL CHANGE THE CONDITION THAT LED TO THOSE FAILURES
Cali serious question. I know you’re a computer guy but, have you ever taken apart an engine?
(I think it’s a good idea for every DIY to take apart at least one engine to understand some basics)
....
Thank you, that is a better explanation for what "lateral forces" may be.
You know far more in your field than most of us combined.
The majority of us do understand clear concepts...
The true rocket-science is in rocket pumps mixture everything else is interesting.
We can focus on what matters TO HELP: Understanding the root-cause of system failure. True SOLUTIONS make a real difference.
Yes of course I've disassembled engines. I enjoy analyzing disfunctional assemblies such as "steering tilt" or "PRND shifter", "trunk control"... I did manage to keep out of gearboxes.
I have doctored my bangy 722.9 with "seemless shifts". Now a perfect system! So I know a thing or two about a thing or two.
> M278 + M157 :
When you add things up that means all these M278/M157 heads around 60kMi "misfire" have a terminal cause ($3k per head + engine labor)
any bank, any cylinder, any valve : WHY #5 ??
MY-15 + 16: better get a compression test ASAP before warranty expires.
> Not adding up... :
The concentrical lateral valve forces does not explain why CYL#5 always gets it the worst!
The thread showed WARPED EXHAUST VALVES. Intake were always mint.
To me that means HEAT is a factor, not simply "concentrical seats issue" showing up late at 60 to 100kMi... nein.
Other random cylinders should be as popular as #5
There is MORE TO THIS STORY that needs to be rooted out...
> CRC says...
"NO INCREASE IN OIL PRESSURE WILL CHANGE THE CONDITION THAT LED TO THOSE FAILURES".
-- Yes very true regarding concentricity but I don't believe this is #5 root issue.
-- Less ACCUMULATED HEAT likely helpful ie. OIL SPRAY EFFECTIVENESS.
> Can Cyl.5 be preserved?
YEA/NAY/POSSIBLE
Last edited by CaliBenzDriver; May 27, 2025 at 06:04 PM.
[QUOTE=CaliBenzDriver;9168261
Racing application benefit from low oiling friction. That's also extremely hot and may affect longevity.
Limited oiling delivers stock performance. [/QUOTE]
if "Racing application benefit from low oiling friction" is that means if you run normal oil pressure that equals high oiling friction and is not good for the engine then or ? because i thought is vice versa
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by KristiyanPetrov
if "Racing application benefit from low oiling friction" is that means if you run normal oil pressure that equals high oiling friction and is not good for the engine then or ? because i thought is vice versa
In this case, "high" (or "low") oiling "friction" is at the molecular level, a.k.a. viscosity. Lower viscosity oil presents less resistance (molecular friction) and therefore more power to the wheels. HOWEVER, absolute power does not contribute to engine longevity. I would rather have a well-lubricated engine that may be a couple tenths of a second slower in 0-60 but lasts longer than to squeeze out a few more hp to the wheels and have lubrication and wear problems.
"Racing application" is not the same as "normal, daily driving application". There is a reason that true racing engines are rebuilt after every race.
if "Racing application benefit from low oiling friction" does that means :
if you run normal oil pressure that equals high oiling friction and is not good for the engine then
or because i thought is vice versa
It's always best to keep things clear and simple!
Higher viscosity increases friction by a small amount compared to low viscosity that welds bearings.
Recent YT clearly showed that: viscosity vs. wear vs. friction
Personal choices range from "MB Approved" 0W-40 stock to 15w-50 for high heat applications. I am camping on 5W-50.
> Redline vs. Driveability:
-- A : I have no way to test drive boost engine above 4kRpm to reach "max torque" control law.
-- B : I am concerned about the driveability power band from 900 to 3000.Rpm.
> The A / B engine PRIORITIES ARE UNLIKE.
The max torque in A does not help engine for B.
We saw that exhaust valves seats wear to develop leakage. No proper cooling can help after damage has materialized.
On a recent video posted here, we saw GM-Corvette racing on 15W-50 oil...
It's to provide a reserve viscosity at high heat output where viscosity thins out.
As long as you stay above spray Rpm, your pistons heat will be circulated out.
The real big deal are THE ROD BEARINGS.
I let you decide what's best lubricant under max stress for your application.
The oil pump regulator maxes out at 60psi...
What oil stays on your bearings under high heat and does not slow down the pistons under max boost ??
-- The API-SN answer used to be called ZDDP with a physical metal layer, cat-less tune.
-- The newer API-SP says it "protects better" is that also true for WOT duty??
Limited OIL circulation is one topic and... limitedHEAT circulation is also tuned for "gas saving".
Slow heat removal is bottlenecked by :
the thermostat
the pump
the ECU Ctl heater
the B2 restrictive pipe path.
-- Master Tasos manufactures a tstat bypass that helps the stock pump seriously circulate heat.
-- Master Surya has repiped his Bank2 coolant to bypass heat circulation. Same bank where infamous #5 lives.
When you race your engine hard more factors than oil MOD are limiting performance.
I already recognize that stock heat removal is ineffectively slow.
Extreme Heat and oil don't play well together. Defeat the heat trap to preserve oil ability to lubricate bearing + cool pistons.
If I had to deal with high power output:
Swap the oil pump for 90psi
Replace tiny squirters for effectiveness
Repipe Bank2 coolant path
Upgrade the coolant pump impeller
Upgrade the tstat for throughout
Not to mention balancing contribution:
equally sealed cylinders
tune equal injectors
tune equal ignition
upgrade rod bearings
the penalties are engine wear/loss.
MOD improved oiling does not fully support high output, nor does stock setup. Heads are particularly sensitive to heat... are exhaust valve stems undersized.. why ?
This is an opportunity for an experimental HEAT removal study. Plan B safe solution: get satisfied were torque crosses power. Don't push drafty unbalanced engine.
> OVERALL: 2 +1 ?
-- We've normalizedALT voltage yoyo + swing
-- We've normalizedOIL rollercoaster
-- Can we normalizeHEAT accumulation with simplicity???
then you can seriously race without warping your wallet. I am pretty sure boosting a solid base mixture is more rewarding than lean trims at 2000.Rpm :
Predictable positioning on time
quiet pistons skirts lower friction
evenly shared contributions
maxed output with efficient cylinders
Instantly strong GDI power mixtures
Stock is setup to detune the predictability GDI thrives on.
Last edited by CaliBenzDriver; May 28, 2025 at 06:48 PM.
> Stay Tuned...
We are going to deal with simple EFFECTIVE BLOW-BY CONTROL in normal driving application. > Focus on the source...
Do not bother cleaning dirty valves, they are NO problem.
It's the root cause that DETUNES engine long before valves build up a visual proof.
Where ppl see dirty valve, I see blow-by.
I considered the system limits without sizing up "every tree in the forest". > Yes we can!
as-is 72kMi on record
> MOBIL1 makes all the best oil formulation. What's their W50 PAO called besides AMSOIL retail ? Exxon - Amsoil relationship...
> Small world...RINGS!
Some of us gathered that LSJr business is to design great piston rings.
He has been in engine racing, oiling formulation and testing and now rings: brilliant combination!
We realize the RINGS SEAL is the key of engine performance.
Nothing's more essential.
dirty valves don't matter... > DIRTY RINGS CAUSE DIRTY VALVES
Last edited by CaliBenzDriver; May 30, 2025 at 06:58 PM.
Shell gasoline additives do a great job in that engine type: clean intake @ 100kMi.
I run premium Costco... my GDI valves don't see a drop of it.
Surya did an awesome job cleaning his valves with ingenuity: pads + chems. No expensive service.
His valves came out looking new.
+++ Non-GDI injection:
These engines also benefit from equally sealed contributions.
Lower looses deliver real efficiency: 33mpg.
Laggy engines are not efficient.
Last edited by CaliBenzDriver; May 30, 2025 at 10:04 PM.
It is interesting to see how oil deposits on the stem but not all around:
Stem stores heat in its mass
Valve seat cools the valves by conduction
Intake stays deposit free
Oil deposits where it burns.
Without extreme heat > no deposit.
> Speaking of limits... :
Lower heat = less burning
Better PAO oil = higher temps specs
less oil burning = more oil cleaning Cleaning is exactly what rings need to seal.
> Regardless of oil selection...
-- Our oil selection would benefit from less extreme HEAT, away from LSPI self-ignition.
-- Oil viscosity and heat are intimately linked -- Lowering heat a little helps win big with cleaner ring seal condition.
i've got quite a bit to catch up on this thread, but i've just hit 500mi on AMSOIL 5w50 an so far performance has been consistent, even on the 90+ degree days. I haven't burned any oil and the oil looks just as amber as when I poured it in.
i've got quite a bit to catch up on this thread,
i've just hit 500mi on AMSOIL 5w50 and so far performance has been consistent, even on the 90+ degree days.
I haven't burned any oil and the oil looks just as amber as when I poured it in.
The results you describe are in direct relation with effective heat removal. Enjoy your journey with patience while stock ECU is firming up your pressure sensitive throttle with instant GDI response. It's all based on best piston seals.
> HEAT BE GONE... :
Accumulated heat no longer derates normal performance... duh!
> Normal pistons heat does...
oil not getting vaporized out through PCV,
oil stays put to seal, lubricate, cool surfaces,
stuck rings are getting cleaned to seal (10kMi).
> Little by little ECU is fine-tuning lean-laggy maps:
4x Camshaft positioning
Individual Cyl spark + fuel
Thermostat opening
When switching viscosity, existing ECU/TCU maps temporarily degrade performance. Be patient: (forget Italian tune-ups!) - ECU just needs 1kMi to register normal data.
Even transitioning from Motul 5w50 to Amsoil 5w50 caused small mapped differences (400Mi)
In fact that's exactly why we upgrade to get these differences. So it's a good sign the engine is registering differences.
The lack of extreme heat cancels heatsoaks and helps preserve engine components and oil seals. It's really welcome to stop smelling hot coolant and leaking oil from low mileage vehicle.
Engine without leaks is basic luxury.
+++ 900Miles in...
Yesterday I noticed again how really unbouncy my chassis drives without super heated struts.
Heat is not accumulated
Extreme heat is not blown off at traffic stops
Front struts hydraulic oil remains effective
Good struts stay put!
Last edited by CaliBenzDriver; Jun 3, 2025 at 06:33 PM.
Thank you once again for this! I was able to order male and female plugs and just did the oil pump solenoid disconnect. I plugged both disconnected ends with the dummy plugs and siliconed both ends to protect from dust and water.
I immediately noticed oil temp comes up to temp quicker. So far so good.
Thank you once again for this! I was able to order male and female plugs and just did the oil pump solenoid disconnect. I plugged both disconnected ends with the dummy plugs and siliconed both ends to protect from dust and water.
I immediately noticed oil temp comes up to temp quicker. So far so good.
Thank you once again for this! I was able to order male and female plugs and just did the oil pump solenoid disconnect. I plugged both disconnected ends with the dummy plugs and siliconed both ends to protect from dust and water.
I immediately noticed oil temp comes up to temp quicker. So far so good.
Thanks again!
Your oil is now helping circulate more heat out of pistons above 2,500.Rpm.
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But lets try keep the word salads focused on the truth 
