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2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
I should get a YouTube channel and instantly become an expert on everything! I know my cars run better since unplugging and surprisingly, my oil seems to stay cleaner (or clearer) longer. (Is that a good thing? I think so since I am using the same oil that I have in the past, and not something new.). The idea that higher (normal) pressure causes premature wear of the chain tensioner because they are applying greater tension is purely speculation on his part. I assume (and could be wrong) that the hydraulic tensioners use the oil pressure to compensate for chain wear and stretch. I know I don't want a loose timing chain slapping around. So, in my opinion, the tensioners are doing what they were made to do.
2004 E55 AMG, 2006 CLS63, 2004 ML55, 2014 E350 sport
I still think theres too much focus in this thread on the oil pressure being the end all cause of scoring.
IMO carbon deposits (fuels with certain additives that create ash in addition to the wrong oil) and mainly injector wear/carboning/issues are still the main culprits (besides the factory bent rods). + That bore liner material is just too fking soft which is why MB changed next to nothing else and only changed the liners back to steel on the m278 circa 2015. Why they didnt do the m157 aswell is mind boggling but they most likely have the failure numbers in front of them.
They didnt do anything to the oil pumps though out production someone correct me if im wrong. And I havent looked but id put a $1 on them running the same type of pump in the m177's.
Last edited by austingtir; 03-30-2024 at 07:07 PM.
I should get a YouTube channel and instantly become an expert on everything! I know my cars run better since unplugging and surprisingly, my oil seems to stay cleaner (or clearer) longer. (Is that a good thing? I think so since I am using the same oil that I have in the past, and not something new.). The idea that higher (normal) pressure causes premature wear of the chain tensioner because they are applying greater tension is purely speculation on his part. I assume (and could be wrong) that the hydraulic tensioners use the oil pressure to compensate for chain wear and stretch. I know I don't want a loose timing chain slapping around. So, in my opinion, the tensioners are doing what they were made to do.
We need to make videos in German. It's more convincing right away
In relation to scoring soft cylinders walls, it's interesting to understand how systems perform at their limits: wet vs. dry cylinders.
We are not normalizing oil pressure to prevent scoring issues but intuitively I believe MOD2.1 is very likely to prevent blowing up dry engines...
Hydraulic work is based on flow and pressure. When pressure is switched from 2 to 4 and back to 2 and less at idle.... our engine software is thrown off guard. It's highly dependant on pressure and unaware of its pressure
What happens to XYZ when pressure is increased or decreased. Then evaluate where we stand.
> Tensioner vs. twin HPFP:
Is there an increased need for tensioner pressure to keep proportioning valve accurately timed by Bank1 intake camshaft ? I don't think not much more.
I think it's the same tensioner part reused regardless of 2x HPFP stressing the timing chain.
The steep 3x/4x lobes are very sharp and don't back feed forward motion into camshaft. Tensioner is impervious to HPFP count.
Unknown GDI condition:
How to enable the advanced GDI timing that makes idle sound like a direct injected diesel?
- this is highly desirable to get this working for torque production.
- I associate that to stiff tensioners with sufficient pressure to time HPFP.
- It's when running MOTUL 5w40 this showed up... ie. pressure sensitive condition.
MOD2.1 should work just as well with any 0W40, not just with boosted 5W-40.
> Overlooked collateral details:
This whole oil tweaking showed me the ECU does not handle particularly well any pressure switching. It sucks at it because of historical look up maps are not pressure tolerant.
That's a bad design gap!
We got an easy way to deal with this limitations: we turned the undesirable oil ups and downs into smooth ramp. The pump itself handles better transition than the ECU.
Given smooth transition the ECU is able to time the engine more effectively at low RPM. Disabling VVT at low RPM causes ridiculous lag! We got that fixed well
The ECU map to pulse the thermostat heater is also altered by switching from trapped to normal heat. So Tstat map needs to learn normal heat Mgt.
Last edited by CaliBenzDriver; 03-30-2024 at 11:02 PM.
While its not the "smoking gun" I do believe if you can have those piston cooling nozzles spraying the pistons and in turn the cylinder walls It's going to make a big difference, It's not *it* but certainly a good one. Every other engine as best i know has the nozzles spraying all the time. And as that piston keeps going up and down it keeps wearing down the oil film, so if its relying on somehow... splash lubrication then It's just a uphill battle. And if your injectors aren't perfect putting more effort on the pistons it again will break down that film and scrub the walls which is metal on metal.
kind of like our connecting rods/main bearings... If we loose that pressurized film things go downhill from there. FAST.
While its not the "smoking gun" I do believe if you can have those piston cooling nozzles spraying the pistons and in turn the cylinder walls It's going to make a big difference, It's not *it* but certainly a good one. Every other engine as best i know has the nozzles spraying all the time. And as that piston keeps going up and down it keeps wearing down the oil film, so if its relying on somehow... splash lubrication then It's just a uphill battle. And if your injectors aren't perfect putting more effort on the pistons it again will break down that film and scrub the walls which is metal on metal.
kind of like our connecting rods/main bearings... If we loose that pressurized film things go downhill from there. FAST.
yes +1
many customers don't understand that old fashioned logic because the advanced Euro additives help provide amazing cylinder dry-lube when squirters are disabled
So the amazing lube confusion turns into complete chaos that becomes rewarding business model - Nice! 👏
Oiling hard working cylinders is not an option, it's a fundamental requirement no matter what premium oil's in use
Mix of gas/diesel engines
Zinc/calcium protection
FRICTION VS. WEAR...
Wall washdowns
BLOW-BY gases!
Piston rings 101
Weak rings springiness
oil cleanliness intervals
20k oil is for CAFE... morons
background acknowledgement is weak rings contaminate the oil through poor cylinder seals.
Whatever you decide to do is based on your decision :
you can keep using modern dry-lube or
you can go proven way in the middle!
We've just leaned that additive particles plug-up the cats and lambda long before that.
One thing that would make sense is to vary using multiple good oils to benefit from their different packages. Hamburgers are great but mixed diet is the healthy solution.
Oil packages... same thing!
Zinc increases drap but reduces wear... so much for gas savings.
I am personally betting that linear oil pressure easily helps engine performance and longevity for free.
Last edited by CaliBenzDriver; 03-31-2024 at 03:11 AM.
Interesting video. So, he thinks the full (normal) oil pressure is too high for the automatic chain tensioners? I can see how he concludes that, but how does that jibe with Mercedes' instructions in the TIPS document to ignore failure of a non-essential part? Plus, we are not at full pressure while at idle, but rather the pressure is linear. I'm more inclined to believe the sudden jump from 2 bar to 4 bar at 3500 rpm is more damaging to the chain tensioner than the gradual, linear increase.
If that engine failure was due to lack of lubrication, I'm inclined to keep the solenoid disconnected. He did allude to using a higher viscosity oil. But does higher viscosity indicate greater oil pressure? His conclusions were confusing to me.
When I measured my oil pressure using the process described in WIS with the solenoid disconnected, I reached maybe 50 psi or 3.5 bar, but it was a smooth increase. I was using Mobil 1 0W-40 oil.
EDIT: Actually, I reached my max oil pressure at 1500 rpm, where it remained. This was at a stand-still and in Park, with no load on the engine. Not sure if driving would make a difference.
Maybe it's because the dealer is going to put 0w-40 oil in it instead of a higher viscosity oil, so they're counting on the thinner oil being present, or, not enough engines with this exact failure has shown up in dealer shops to the point of raising any red flags yet. I believe the tech must submit a request for information on abnormal failures, once those requests reach a specific number does it investigate possible causes that would involve the solenoid and/or oil viscosities.
The only official answer to expect is a social finger, high up!
l
I would put my money that the responses to it would have been just "that guy or those people are idiots" but to my surprise my Mercedes Tech friend said that basically every reply was positive or at worst, neutral. Basically the main theme was the EU has very strict CO2 restrictions and they are all related to fuel consumption, so manufacturers have to modify these otherwise perfect engines to have complex fuel savings apparatuses in this case the two-stage oil pump.
I would put my money that the responses to it would have been just "that guy or those people are idiots" but to my surprise my Mercedes Tech friend said that basically every reply was positive or at worst, neutral. Basically the main theme was the EU has very strict CO2 restrictions and they are all related to fuel consumption, so manufacturers have to modify these otherwise perfect engines to have complex fuel savings apparatuses in this case the two-stage oil pump.
We know how rules get delayed until the necessary technology becomes available.
I can see how detuning our engines prevents recording normal fuel consumption. Good for them at least their laws are less flexible. 👏
All that lag is lack of enriched mixture during acceleration. When most of the engine power becomes available above 3500.RPM, its harder to pollute during civilized law-abiding driving style.
Bosch did more than provide us with a dual-rate pump, they also under rev'ed it with primary gear ratio. MB chipped in special oil passages through timing cover without any seals. This has huge potential to drop pump pressure.
We are able to offset internal leaks with MOD2.1 by barely boosting the oil viscosity. I think it is important to cool pistons at normal driving RPM nor just 2500 RPM.
Last edited by CaliBenzDriver; 04-01-2024 at 03:05 AM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by CaliBenzDriver
yes +1
many customers don't understand that old fashioned logic because the advanced Euro additives help provide amazing cylinder dry-lube when squirters are disabled
Interesting comment Lake made about fuel additives...
Interesting comment Lake made about fuel additives...
See for me the solenoid is not only "Pull The Plug" then done - What I witnessed the engine doing after MOD1 is meaningful.
It impacts the engine software to enhance your engine + tranny + brakes for $5 oil shot.
Understanding this led me to MOD2.1 to extend the goodness of MOD1. all the way to 900.RPM. for a perfect lag cure.
Lag was caused by a series of conditions leading to a lean during acceleration. The free fix is rock hard gas pedal. Mine has now becomed pressure sensitive.
> OILING... BECAME DRY :
We know the old "There's No Replacement For Displacement!" - I think there's something similiar to be said ABOUT OILING.
Advanced additives help metal FRICTION but then lack of COOLING becomes center stage with extreme heat that burns any oil into carbon sludge.
Bosch and oil companies are trying hard to market novel solutions while harvesting billions.
The No1 firmware bug is the lack of pressure awareness.
The Pressure step changes corrupt the 4x VVT lookup maps that impacts timings of HPFP prop.
valve.
The pump manufacturer is not going to transition pressure any smoother so only software has to step forward.
Here is a cost effective solution: let the pressure be normal (gear pump). Simply pulse pressure out to create/simulate lower pressure.
When mgt valve fails open then simply limp mode the engine based on $5 pressure sensor or simply 4x VVT in wrong position.
MOD1+2 provide stepless linear pressure the VVT can adapt to given enough viscosity to counter the jerky HPFP lobes.
> EXPERIMENTAL ACTION STEP:
I recommend incremental shots: 100ml of 15w50 up to about 300ml: conservative approach to viscosity change. Play around at 4kMi before future oil change
Then witness overall Temp and fan activity.
The goal is to squirt pistons at driving speed or 1400.RPM.
> Lube vs. Pressure:
I understand MOD is **NOT** about lubrication/wear.
Advanced oil is designed to dry lube to some extent.
What MOD's are dealing with is marginal available oil pressure. We needs hydraulic pressure .
> MOD3 stuck in the pipe -
Needs to further study to instrument ECU.
It is an hardware bug that I believe lets the measurement reference ground float loosely. This tanks skews a whole set sensors collection.
Need to find the time to address this. If my engine is going to stay cool on MOD2.1 then I may not go forward fixing MOD3 GND issue.
> Around my corner:
AKEBONO brakes
MAHLER thermostat
LEMFORDER control arms
MOD3 tests floating reference
Cawl painted GND + wiper greasing
LED Module conformal coating
Waterproofing front side radars
Happy holidays
Last edited by CaliBenzDriver; 04-01-2024 at 04:30 PM.
What do you mean by pressure step?
Are you saying you bought a solenoid to plug into the connector while it's unplugged from the engine?
What do I call "pressure step":
The step is the sudden transition between 2-to-4Bar and from 4-to-2Bar.
The VVT are positioned using pressure managed by individual solenoids.
When that pressure varies drastically it throws the exact position off into the weeds until PWM gets recalculated to match position.
We know the HPFP proportioning valve driven by the ECU in relation to HPFP lobes. This is where exact timings are paramount. The ECU can not work exact timing with jittery camshaft position rendered by CPSensor.
In addition lack of sufficient base pressure disables Bank1 Intake camshaft exact positioning when HPFP lobes tug on the camshaft.
When the fuel pressure control is altered the exact mixture is unpredicted well. This creates a LEAN that translates into LAGGY response.
How do I know so... I've tested the relief fix with incredible results: rock solid pedal response with "unlimited" torque.
The ECU can compute exactly what the engine needs when given good data. It can tolerate a lot of extremes by matching de-tuned timings. The opportunity is yours to help your ECU with good stable pressure.
All of this is going to hold true across many makes that implement the dual-rate oil pumps.
-- It's not rocket science to imagine sudden pressure changes impact systems that precisely depend on it. The ECU can adapt to slow oil viscosity changes such as RPM pressure change or old oil loosing viscosity.
-- Tensioners are dumbo... they just need enough pressure to counter camshafts.
-- Squirters are dumbo too... they just need working pressure to spray hot pistons.
MOD2.1 it is! ✌️
Last edited by CaliBenzDriver; 04-01-2024 at 09:44 PM.
What do I call "pressure step":
The step is the sudden transition between 2-to-4Bar and from 4-to-2Bar.
The VVT are positioned using pressure managed by individual solenoids.
When that pressure varies drastically it throws the exact position off into the weeds, yes?
We know the HPFP proportioning valve driven by the ECU in relation to HPFP lobes. This is where exact timings are paramount. The ECU can not work exact timing with jittery camshaft position rendered by CPSensor.
In addition lack of sufficient base pressure disables Bank1 Intake camshaft exact positioning when HPFP lobes tug on the camshaft.
When the fuel pressure control is altered the exact mixture is unpredicted well. This creates a LEAN that translates into LAGGY response.
How do I know so... I've tested the relief fix with incredible results: rock solid pedal response with "unlimited" torque.
The ECU can compute exactly what the engine needs when given good data. It can tolerate a lot of extremes by matching de-tuned timings. The opportunity is yours to help your ECU with good stable pressure.
All of this is going to hold true across many makes that implement the dual-rate oil pumps.
-- It's not rocket science to imagine sudden pressure changes impact systems that precisely depend on it. The ECU can adapt to slow oil viscosity changes such as RPM pressure change or old oil loosing viscosity.
-- Tensioners are dumbo... they just need enough pressure to counter camshaft.
-- Squirters are dumbo too... they nust need working pressure to spray cool pistons.
MOD2.1 it is! ✌️
your talking about the pressure spikes if the oil pressure reducing solenoid was plugged in as in factory?. I get what you mean. And by unplugging as we know, the pressure doesn't jump around anymore as it's mostly linear with engine rpm and oil temp. Which is much better for everything and engine management.
your talking about the pressure spikes if the oil pressure reducing solenoid was plugged in as in factory?. I get what you mean. And by unplugging as we know, the pressure doesn't jump around anymore as it's mostly linear with engine rpm and oil temp. Which is much better for everything and engine management.
+1: yes exactly!
Stock performance is de-tuned by the solenoid switching pressure and the VVT being blind to these giant steps 2-to-4Bars then 4-to-2Bars.
This is poorly implemented so we "pull the plug" to transform chaos factor into smooth predictable maps.
Same thing with the amazing voltage regulation... it's poorly implemented so we unplug ALT. to prevent battery drain-by-driving. This I believe is linked to MOD3 floating GND Ref when managed output is near 12.6VDC.
The engine timings are measured with micro-seconds precision. That is not compatible with goofy VVT timings.
> MOD2.1 ... Paving The Way:
With smooth predictable timings we get:
Unbelievable from 900.RPM torque
ECU-TCU coordinated smooth shifts
reduced blow-by leakage through dry rings
reduced intake oil swamp (NA Eng.)
increased vacuum pump output to brake booster
Predictable MAP sensor to work TCU kick-down.
With improved oil viscosity your pistons can now get cooled at driving RPM instead of dry below 2500.RPM.
We clearly understand dry lube oil additives are essential for protection. Do not change your favorite oil, instead boost it using Mob1 05w50.
Last edited by CaliBenzDriver; 04-01-2024 at 09:52 PM.
Gotcha, yeah all valid points. I'm not sure on the voltage regulation. assuming what I think your talking about, It's very common practice across the board, Again its to save fuel mileage, that one i can't say really bothers me because the electronics all run on 12V or sensors are 5V because in theory, 5v is a guaranteed steady state and will never change, 12V *could* but shouldnt. My chevy truck does that, turn on headlights, blower motor, voltage goes up, but once the battery is "full" and your cruising with no loads down the highway the voltage will hover around 12.8. I've had people think their alternator is bad because of that.
Gotcha, yeah all valid points. I'm not sure on the voltage regulation. assuming what I think your talking about, It's very common practice across the board, Again its to save fuel mileage, that one i can't say really bothers me because the electronics all run on 12V or sensors are 5V because in theory, 5v is a guaranteed steady state and will never change, 12V *could* but shouldnt. My chevy truck does that, turn on headlights, blower motor, voltage goes up, but once the battery is "full" and your cruising with no loads down the highway the voltage will hover around 12.8. I've had people think their alternator is bad because of that.
+1: yes 12.6V or 12.8V float voltage is great because it is purposely neutral not drain battery.
-- I really like Bosch "opportunistic charging" feature from 12.6v /13.7v /14.4v /14.9v: AWESOME!
-- What I dislike is when FAULTY ECU cooks both (Main + Aux) batteries with 90Amp ... NO CODE, NO CEL
-- That is over 1300Watts of heat the battery must dissipate - BATT gets cooked with the power of a toaster or coffee machine. I've had a problem with that non-sense.
Again here SMOOTH WINS THE RACE!
Normal battery current decrease smoothly from 15A down to less than 1A.
This is when MOD2.1 branches into MOD3 - We shall see if ECU suffers from "floating reference GND"
A +/- 0.5 V is a huge deal in battery world. It can turn 12.6V float voltage into a 12.1V drain followed by 90A toasting until BATT. LIN sensor stops the rage.
Batt sensor tracks internal batt temperature.
These threshold values are essential for survival of lead-acid AGM. Let's remember system AGM is built to supply 850A punches... it's got muscle!
Learn to keep an eye on your Voltage/Amps cluster display. Specially if your chassis has a proven appetite for weak batteries.
Let's stay on topic in this SOLENOID thread ... not batteries!
Our host @kevm14 has done a really intelligent OP summary to help everyone concerned.
Last edited by CaliBenzDriver; 04-02-2024 at 01:54 AM.
Just wanting to add here that I’ve put over 2k miles on my SL63 since unplugging and have used very little oil. Checking the oil after a good warm-up and run, then letting sit for about five minutes shows mid-way on the stick. Turbo engines should use some oil through the seals - when I got the car the level was up to the full mark on the stick - this is about what I’d expect from
normal usage but seems to be outside the norm for the M157 (in terms of it over-consumption of oil).
Also to note, the oil is still a very nice amber color when wiped using a white paper towel. Very clean. There is also very little indication of a hydrocarbon-like smell to it. Much less than that from my my truck and my boat engines. I’d say that unplugging has shown its benefits at least according to history around here.
By the time she hits 3k miles the SL will be due for the summer oil change; it’ll be interesting to see if the ECU decides to warn me about being low on oil.
Just wanting to add here that I’ve put over 2k miles on my SL63 since unplugging and have used very little oil. Checking the oil after a good warm-up and run, then letting sit for about five minutes shows mid-way on the stick. Turbo engines should use some oil through the seals - when I got the car the level was up to the full mark on the stick - this is about what I’d expect from
normal usage but seems to be outside the norm for the M157 (in terms of it over-consumption of oil).
Also to note, the oil is still a very nice amber color when wiped using a white paper towel. Very clean. There is also very little indication of a hydrocarbon-like smell to it. Much less than that from my my truck and my boat engines. I’d say that unplugging has shown its benefits at least according to history around here.
By the time she hits 3k miles the SL will be due for the summer oil change; it’ll be interesting to see if the ECU decides to warn me about being low on oil.
That's interesting to read. Sounds like your have lowered the stress level on your engine - It shows appreciation for what you're doing.
Your 2kMi oil aging amber means it is actively cooling your pistons instead of burning black on dry-pistons with the stock non-MOD setup.
Burned oil has degraded viscosity and that causes less piston cooling and further burning cycle at higher RPM.
What's been your experience of changing oil viscosity ?
How are the VVT gears doing vith driveability ?
How about gears 1-2-3 ...
Kick-down likes better low blow-by.
Masive torque is a nice replacement for lag: EXCELLENT TIMINGS
Last edited by CaliBenzDriver; 04-03-2024 at 04:20 AM.
I want to share something, on oil, but not about the oil solenoid defeat. It is Crankcase Positive Pressure system to make sure you oil stay healthy.
It is about how you guys..... more so if having turbocharged engines and GDI, need to invest in a simple low cost manometer. Under US$250.
Something like this :
5 PSI version is enough. We need to measure super low vacuum or positive pressure of the crankcase
I brought this up because I troubleshoot a friend's engine M271.860 1.8L GDI Turbo, which I am smelling fuel when engine is already shut down.
I thought it was the fuel vapor venting system, but it is not.
It is is a failing PCV system, which can't evacuate the piston blow by bad air properly. I am seeing very minor positive pressure. About 1 millibar only. By right it should be -20 millibar or lower ( vacuum ).
I said bad air is because, during cold start a GDI engine due to its injector inside the combustion chamber and not a distance away like Port Fuel Injection, and cold engine piston rings are not ready yet to
trap properly the piston blow-by gas, a lot of the still rather un-burned fuel ended up to the crankcase as extra piston blow by.
And if this fuel rich bad air is not evacuated by a proper working PCV system, your oil will be diluted with fuel ( hence smell of gasoline in engine oil ) and the oil will break-down faster.
Too much fuel diluted into engine oil will kill friction surfaces where oil is supposed to make it float/separate, as the oil is thinning can't keep its viscosity.
Also the oil looses its good properties when once too much fuel dilution occurred.
ALL engines have piston blow-by. It is just HOW MUCH. New and well maintained engines has less blow by or within factory limit.
Abused and neglected engine, will have so much blow by, best you buy 1 gallon of fuel and burn the whole car down....
Here is the crankcase pressure of the M271.860 engine with a failing PCV system.
Sorry, my camera was fogging up by few minutes into the test. Unit is mmHg ( millimeter mercury )
Conversion to a more familiar units of pressure
MB does not specify what crankcase pressure is to be expected, not in the WIS, but we know it has to be negative pressure aka vacuum.
BMW has its spec.
This is my M276.820 3.0 Turbo. In miilibar. Hot idle.
This is BMW specs for crankcase pressure.
So how bad is my friend's M271.860 engine oil smell ? BAD, very gasoline like.
How is the oil color after only 1,000KM/600miles, very DARK.
Now, M271.860 turbo engine has two separate PCV system. LOW load and FULL load ones.
The one which seems to be failing is the LOW load one, which is the one 90% of the time in operation during a typical "polite" driving.
I can't believe my nose is smelling such strong fuel vapor smell from only a positive 1.3 millibar of crankcase pressure.
The damaging effect is REAL guys.
So go and buy the tool and inspect your crankcase pressure.
You can test at engine oil dipstick hole or at engine oil cap.
The test I done both to M271.860 and my M276.820 is sensing from engine oil dipstick hole.
If your engine is like M271.860 where its cylinder head plastic cover is the PCV system for FULL LOAD, test it at the engine oil cap too.
Audi/VW engines is using its cylinder head plastic cover as its PCV system .
M271.860
.
M271.860 LOW Load PCV system.
M276.820 3.0 Turbo Two Stage PCV system, in 1 package. This design is awesome.
.
Oky doky.............. go and give some tender love & care to your engine.
I did this same thing while thinking about our wire harness oiling issues. It did not make sense for a system that should be running negative pressure to be pushing oil into the harnesses. I get the electrostatic wicking but for something to change velocity there has to be an unbalanced force. So, I did the same thing as S-Prihadi; put a pressure sensor in the oil dipstick tube and monitored pressure.
I did the first run on my wife's Infiniti and sure enough there was the negative pressure that would be expected from a modern engine. Pull a dipstick on a running car and watch it struggle with the vacuum leak. This has been a great thread as it has covered a number of oil related issues that face our engines. S-Prihadi has shown leadership in his data driven approach to understanding and diagnostics.
Two of the primary issues that I have had with my M157 have been vacuum related, a PCV system and the vacuum check valve. Its the little things.
Anyway, time to test the M157 again just to see what is happening. I am not as good at recording but I will try and feedback some information.
BTW: there was a good video on how a person can diagnose ring and piston problems by tracking pressure pulses in the crankcase.
Thanks to all for the information.
If the solenoid is stuck closed - no CEL for many 157 engines and only soft code
if the solenoid is stuck closed - no CEL and only soft code
yet one of these is a catastrophic condition, correct? Tell me what I am not understanding.
GOOD:
- The ECU reads the solenoid electric circuit to flag if the continuity is wrong (open or short).
- As soon as the wiring becomes defective a soft code is activated with or without CEL
BAD:
- When the hydraulic valve gets jammed by aluminum particle, the pump output is limited to low pressure only
- That explodes the pistons and spins con.rod bearings.
- No code, no warning: RIP
One can let the solenoid stay in place but unplugged: MOD1.
It will never be activated at all to prevent it from getting jammed.
The oil additives help the engine TOLERATE random dry-lube butlow pressure does kill the engine under 10mn. Under stock condition the ECU monitors calculated engine load to supply a burst of oiling .
++++
> Pump controlled by "solenoid valve":
-- Active SOL. = open = limited volume = low pressure.
-- Inactive SOL. = closed = linear pressure output.
-- RIP Conditions:
- The electric coil can be ok on a jammed valve!
- ECU has no safety sensing to prevent failure through a simple "limp-mode".
- ECU only senses electric solenoid and has no feedback about the actual valve pintle.
We could design a safety module that senses oil pressure vs. solenoid signal and triggers a safe-mode.
Last edited by CaliBenzDriver; 04-03-2024 at 03:50 PM.
03-30-2024, 06:43 PM
