Originally Posted by kevm14

So is it your contention that the oil pump producing say 35 PSI instead of 25 PSI over those driving conditions* will harm overall engine longevity? Because I think it's quite the opposite.

Originally Posted by kevm14

As has been discussed ad nauseam, oil pressure is a function of oil pump rpm, oil viscosity and resistance to flow (oil pressure is generated in the first place because all of the journals and galleries and nooks and crannies that provide a restriction to flow).

Originally Posted by PeterUbers

and perhaps, for the M274 engine, as documented in the technician tips bulletin above, leaving the faulty solenoid is appropriate and can be "ignored" (fact)

that being said since I still haven't seen what the M157 document (a factual document) shows it's unclea; and as you suggest, what possible downstream affects this could have overtime. And of course, it peaks my curiosity why a check engine light illuminates (fact) for certain models enough for other models.

What's the unknown unknown? Perhaps nothing, but my simple man understanding is that good science works best when the hypothesis can continue to be challenged and prevail vs preventing any further challenges to the hypothesis when you obtain the outcome you're happiest with (confirmation bias). Teach me if I'm wrong.

I appreciate your willingness to have this discussion, it's always been healthy for me to keep seeing different angles of the same thing.

Originally Posted by PeterUbers

thanks for confirming my thinking.

Originally Posted by kevm14

Because it has to do with the emissions and fuel economy certification of that powertrain combination in that vehicle. Same engine and same oil pump. As per my previous example it's why the check engine light comes on if I delete my diesel particulate filter. It's an emissions out of compliance light first and foremost.

Originally Posted by crconsulting

I can explain the spirit of this WIS document (and others like it)
As yourself this? What mileage do you think you would see that wiring failure for the Solenoid?

75k, 100k, 150k? So rather than subject the customer to a costly repair for a car which most people won’t keep past 150k, MB opted to let it go. (or give the dealer an option to present to the customer) Dealer may still opt to do repairs at their discretion.
it’s one thing to drive the car for another 10k -20k, an entirely different matter to put 100k on that configuration.





Haha, Yeah my reservation for posting on subjects, is folks tend to take things personally.
They really shouldn’t, we’re all after facts and asking questions is a natural process in order to extrapolate accurate data…




Looking at things differently, and asking questions is all part of good engineering. 👍


Good Luck Folks!

Originally Posted by crconsulting

It’s going to be more like 25psi to 60psi or so.

Originally Posted by crconsulting

But that’s where the details are also. Some modern engines have smaller oil galleys and oil delivery can be exasperated by thick oils in cold start conditions….
Adding more pressure to this scenario will only increase loads on pump, shaft and whatever it is connected to with no improvement on lubrication. (and cavitation can be a thing too) The duty/load cycle will also increase overall.
It used to be somewhat common to break oil pump shafts on High Pressure, High Volume pumps…

Good Luck.

Originally Posted by W205C43PFL

To answer one of your questions, surprisingly common to have the solenoid fail, the main failures I seen reported on the forums are from M274 engines, followed by M276 engine, there are cases of other vehicles, if I recalled correctly a G-wagen. It is surprisingly fragile. So if the pressure fails at low mode, it can be catastrophic.

Originally Posted by crconsulting

Sorry missed your answer,
Sure, It’s definitely a valid concern 👍

But, when WE say “surprisingly common”
How much percentage wise, do you think that would be in proportion to production?
Also, mileage on said vehicles?

We tend to loose sight on forums, as problems become hyper focused, and forget the huge numbers in which these engines are produced.
I’ve seen reports of brand new engines failing in new cars, It’s an anomaly, but if you’re the person this happens to, well it sucks….


Good Luck!

Originally Posted by kevm14

I don't think anyone has measured such a wide swing.
Peak oil pump loads are at high engine loads and over 3500 rpm which the pump already experiences bone stock, across the whole range of oil viscosity. Unplugging doesn't increase those.

Originally Posted by W205C43PFL

After perusing the threads, I realized they didn't state the mileage, some are also a failed harness, not the actual solenoid.

Originally Posted by W205C43PFL

CEL especially not flashing ones are usually emission related (as you know) such as a bad oxygen sensor, given how much tighter European regulations had been over the years especially since 2019 and other years of introduction of OPF, that explains why when the vehicle is running less fuel efficient or emitting more emissions (in the case of a failing oil pump solenoid), it throws a CEL.

Originally Posted by PeterUbers

makes sense.

i suppose if people will bring up that m274 document about the tip "disregard" the code and move on, I would like to lean on the m157 document that must exist as to what is recommended to the technician, if nothing else but to add to the database of facts provisioned by the engine manufacturer. Seems fair enough, particularly if that m274 bulletin keeps invariably getting cited in this thread that is in the w212 amg m157 forum.

so the CEL comes on for some m157 engines and not others because of the combination of criteria related to emissions for that particular vehicle - this Is the hypothesis.

Originally Posted by kevm14

Is your hypothesis that increased torque on the oil pump during lower load operation will meaningfully decrease its life?

Originally Posted by kevm14

And that risk is MORE concerning than running the rest of the engine on artificially reduced oil pressure to microscopically increase fuel economy?

Originally Posted by kevm14

And that the oil pump overall has NO factor of safety such that simply unplugging the solenoid will actually lead to its early failure?

Originally Posted by kevm14

And your VVT comment - are you insinuating that we are over advancing cam timing by increasing oil pressure at lower RPMs? I hope the answer to all is no....

Originally Posted by crconsulting

it’s not load operation, but constant operation at a higher load. Does that make sense? Oil pump will probably be fine what you have to look for is what drives the pump.



How would we know? If the engine is designed for low pressure operation for 40ft lbs of torque 60 percent of the time, if we increase that load to 80ft lbs aren’t we the ones redesigning how this system is designed to operate. Aren’t we the ones ARTIFICIALLY increasing pressure? There are hundreds of post with people well in the 200k mark and no mods right?
How do we know with all the conjecture and no solid measurements.



Sorry maybe you can clarify this, not sure what you mean?



Well lets see, everyone in this thread raves about low end pickup and improvement in bottom end drivability.
What would you think this is causing this Kev?

This is an old road racer trick to advance cam timing a few degrees. Nothing new here. Except we’re achieving this through oil pressure timing.
Normally downside of this is the loss of top end power. (Not a concern with the VVT here) and the propensity for detonation/pre-ignition…

As I said, I’m not here to convince anyone to do anything, just trying to present some engineering here.

You easily google “advancing cam timing degrees detonation pre-ignition”
Theres a LOT of variables here and is this happening currently and detrimental to these motors?
F—— if I know, as I don’t have an engine Dyno and neither does anybody else here.
But the engineering says when you advance cam timing, the results are an improvement in bottom end performance but a higher probability of detonation/pre ignition….


Running out of time for today, but have enjoyed the productive dialog 👍

Cheers Guys 👍

Originally Posted by PeterUbers

this is a great post - thanks for speaking about the unknown unknowns

Originally Posted by crconsulting

Thanks Peter,

We used to create list of theoretical pros and cons in engineering meetings.
On one side all the pluses and the other the possible negatives.
it helped stimulate discussions and helped discern real versus perceived issues.

Anyways As I said, appreciate the work and time people are putting in this….

But I’ve learned to respect the basic laws of motion: For Every Action There’s a Reaction.
Cheers..

Originally Posted by E63SAMG2014

I kept myself updated through this 3k+ posts. And simply came to the point to call it time of death on it.

enough opinions, observation and speculations has been stated.
Yet not a single factual concrete data.

all mentions of possible “benefit” not a single post mentioning what the possible side effect/negative effects it will have.

No one on this thread has the credential on being a M157 engineer. I salute those who are brave to experiment on a M157. To each their own I always say.

Mixing quarts of 5/50 with 5/40 is simply
ludacris and your ecu will adapt? Your vvt and other components will be harmed before anything is my guess. Again, why volunteer to be a lab rat to this experiment?

Not to mention
keeping the fan always on, thermostat open always and oil pressure on high always. So on and so on jeez man. Do any of you really have considered the aftermath? Besides the positive and benefits? There will always be side effects/negative impacts to it, always. And none of all you have the credentials to prove it besides your mere observation/speculation.

this thread is misleading so many owners and potential owner. It’s almost toxic to this entire forum.

So much with confusion of he said she said.

not to discredit all the brave souls who have experimented in hopes of beneficial gain aspects.

this whole thread is fear mongering on owners who wish to keep their car healthy/long almost tricking them into unplugging perfectly good solenoid function. In hopes their cylinder wall/oil pressure is proper, as if it wasn’t before.

I can potentially see the benefit if your pushing 700+ stage 2. At that point it won’t do much harm IMO compared to a stock M157.

when a member speaks against the idea of it. There are owners such as Jetta getting sensitive. It may shy other owners to chime in their other point of view, but not myself.

go against the grain, at your own risk.


carconsulting is the only logical post I’ve read through this entire 3K+ post on this thread.

again cheers to you mate

Originally Posted by JCM_MB

It may be true that an engineer at MB is more familiar with their product, but it is also true that they have made major blunders in the last 20 years, and counting:
1 - SBC debacle
2 - Fuel tanks for W211 leaking, and do not mention the PZEV version
3 - M272/M273 debacle, and let us not forget M278/M274 recent issues
4 - M156 headbolts and injectors
5 - W212 rear subframe still counting, steering rack bolts
6 - Decisions such as removing the service opening of the fuel pump in the tank for the W166 platform, so now a tank removal is mandatory. The previous versions service was below the rear seat.
7 - Every MB loves to drink water through several entry points .
8 - ?? Just cannot keep track of all the platforms

Sometimes I think the MB engineers have their heads stuck in the ground for a better word.

Let us focus on the facts as they are being discussed, and stop idolizing the creators.

NOTE: I am an engineer, and I think I know where @crconsulting is going. Just putting my thoughts together.