I been away from the thread a long time.
I hope no more fights from the Pro and Con group.

As long as those who un-plugged the oil solenoid is willing to take his/her own risk and understood that his engine type may not be the same as those who has un-plugged, I guess it is fine.

For my engine M276.820 3.0 Turbo, oil solenoid defeat (un-plugged) has no remarkable improvement compared to those with M276.9 NA 3.5L engine.
Bear in mind my car is low mileage at 44,000KM today and is very maintained well beyond 99.9% of what owners in this forum would do,
but I also beat the hell out of my engine and tranny as a daily.

My simple logic is, the oil pump solenoid is not always set to low oil pressure by the ECM when you drive agressive....anyway.
Thus the more agressive you drive, the less benefit oil solenoid defeat (un-plugged) will be, because ECM will defeat it for you already , before 3,500 RPM.

As to what extra wear and tear on the oil pump or the chain driving it or the tensioner holding it, I can't comment as I do not have enough mileage on my engine M276.8, remember M278/M157 uses different oil pump .
So my experience would not be the same as your engine-s.

Now for the VVT response with oil solenoid defeated or standard, is no difference for my engine.
I say no difference is because the VVT will always follow what the ECM target degree is, no matter how rough or smooth I drive. No over or under shoot.
Again please be reminded that when your throtlle hard, the ECM will defeat the oil solenoid anyway....even before your engine hit 3,500 RPM.

---------------

First 2 videos below starts with stationary to WOT till 3rd gear.
And then I drive normal after that 3rd gear WOT and a bit mix of agressive and calm.
120 seconds log is maximum and minimum for Xentry if we want to save the file to a CSV.


This is oil solenoid untouched. As is, standard. 3rd Sept 2023. UTC 16:08 or local time +7 for me, or 11:08 PM.

.


The very same road, this is oil solenoid defeated. 3rd Sept 2023. UTC 15:38 or local time +7 for me , or 10:38PM




This is the Xentry only view compilation of both above and zoomed up for better view, it still has the audio for the engine.

.


I can change oil solenoid defeated or not in 1 second. I have a switch and dummy load for it. As long as when I choose it the engine is OFF, there will be no DTC.







.



.





--------------

The bulb intensity tell me what the ECM is doing to the oil solenoid, because the 2 bulbs are the dummy load and ECM does not know.
The amperage is good enough for ECM to be fooled that it is an Oil Solenoid.
The bulb is special Honda motorbike instrument cluster use, 3 watts very cool operation incand bulb. No more than 80C operational temperature.
The 5 watts T10 incan bulb our W212 uses, by Toshiba, that thing is 144C easy, very hot operation.

This is how the dummy load works


==============

Dont worry about oil solenoid getting stuck yada yada, when you have oil pressure sensor like mine to verify, you can switch the oil solenoid defeated/normal every damn day it is OK.
Also in normal operation a standard non-defeated oil solenoid, it will turn ON-OFF so many times by ECM command everytime you drive....anyway.
If you keep your oil clean, I guess the oil solenoid if it dies it wont get stuck mid way.

===============

As to why M276.8 3.0 turbo won't feel much ( or any ) power benefit compared to M276.9 NA 3.5L is because E400 turbocharger is a city comfort turbo which has peak torque 480Nm as low as 1,400 RPM.
No amount of VVT magic can beat turbocharger for the oomphhh of extra 160Nm at 1,400 RPM, where M276.9 at the same 1,400 RPM only has 320 Nm.





M157 is a sport engine. But the peak torque is at 2,500 RPM, and a beast of a torque at 800 or 900 depending on performance package.
Perhaps those M157 owners who feel the benefit of un-plugging is having the joy at 1,500 - 2,000 RPM where the torque is on a steep rise.




M278 is not too sporty engine, but powerful nevetheless as a semi-comfort-sporty engine.





I think we need to wait for more mileage from those who defeated their oil solenoid, if and when actual extra wear and tear occurs at X or Y or Z components.
Probaly by then ( older and higher mileage ) the cars would be sold by your guys because it is too old

As for me, I am on a confirm path to keep my car at least to 20 years, but too bad my annual mileage is very low. It will not even hit 100,000KM by its 20th bday, guaranteed.
So for my M276.8 3.0 Turbo wear and tear for being un-plugged ( if any extra wear ) may not be a good example for the database.

Anyhow before 20th year all my timing chain and plastic guides and all 3 tensioners will be replaced anyway, because I hate plastic in the timing system. All bought already in 2024.
There are two plastic guide I can not buy without buying the timing chain...LOL. Thus the L & R timing chains will be replaced, because I will replace the plastic guides.
I have not bought oil pump short timing chain though or any metal gears which drive them from the crankshaft.
I did not yet buy 4 x VVT + 4 x oil control valves yet too. I doubt it will do the knocking dance by year 20th or under 100,000KM.

So, please all of you enjoy your engine with whatever mod you are doing to it. and we all don't need to fight.

.

 

I’m not certain that the manual says not to use 5W30 She’ll Ultra.

Our manual says to use MB229.5. When you check the 229.5 rated oils, you see that Shell Ultra is rated at 0W30, 0W40, 5W30, 5W40 weights:

 

This is a weird one.
I don't know exactly where the temperature sensor(s) are located. I also don't know how the logic handles signals from it/them. Now of course I want the engine to run within a specific window.
I find it odd though that even when the oil temp reaches for example 104 degrees I get no increase whatsoever in coolant temp even after an extended period and I'd expect from conduction that the block temp would rise even if by only a single degree before it drops back down again as the cooling system does it's thing due to the hysteresis of any feedback loop.

Can't quite get my head around it.

 

Mine says use ONLY 0/40 to 5/40 whilst meeting also 229.5;

I would add that when your normal oil isn't available it doesn't say to substitute a different viscosity it says to use a different approval spec.
Now, I'm not crapping on a single person here as I think there are valid and proven points made. I just want to understand where my motor is FIRST before I go ahead and make any mods.

 

I don't think your engine in its current condition is ready for any experimental oiling.

Clearly it may not be a good candidate due to use of low viscosity W30 oil (**).

Find a way to run the common stock 0W-40 or 5W-40 MB lubricant for 15 to 20k Miles.

Perhaps you can share with us how is your engine-tranny driveability while using W30 oil.

• How is the throttle response ?
• How are the gear up/down shifts ?
• How is the engine heat ?
• How much oil is lost between service ?

Use these notes to request better stock oiling from the service agent.

**: you could consider finding a Valvoline cleaning oil to help cleanup pistons rings. I've never used that because of low-viscosity but you are reportedly there at W30 already so perhaps worth some thoughts .

 

Agreed, that's what I want to see what the deal is first.
I think I might send the service centre an email and ask why they are using an unspecified oil, (I expect them to fob me off). But aside from that yes, 0W/40 from here on for a while.
Other than the oil running a little warmer that usual everything else is fine.
Throttle response is the same, noise hasn't changed, economy is good, - circa 26mpg on average, gearbox is good, (except when stone cold). Had the car 5 years, only once ever had to top up off schedule with a litre.

 

Did I read correctly... your 5w30 oil is running warmer or do you mean the engine is running warmer ?
The difference in statement is important because these two are opposites.

hotter oil --> cooler engine
cooler oil --> hotter engine
Pistons cooling at driving Rpm is all about effective spraying which is based on available oil pressure.

5W-30 is unlikely able to cool near 2000.Rpm... So high heat but more "gas savings" right ?

Inquire about getting switched back to an "MB-Approved" 0/5W-40 lubricant replaced early before it is sheered down to 10W-30.

 

Sorry, I didn't catch that you had an AMG - the mobile version doesn't list vehicles.

Of course your manual (and you) are correct.

 

No worries dude, no harm done.

 

You did hear correctly.
The annoying thing is they didn't tell me so I don't know exactly when things changed.

I think I'll change back for a while and as I know how I drive, if I get the results I expect then I can assume there is no hidden issue.
Thanks for the info.

 

Everyone, I'm in a bit of a state right now. I realize that this is for the AMG models but I'm desperate and I'm crossing my fingers that I won't get flamed for posting my (in my mind) what is to me, a very urgent situation, in this thread.

My car is a 2018 C300 4MATIC with the M274 engine with 98K miles. I searched the main section for my car (C300 section of MBWorld) but don't see any info in there about someone having this issue and figuring out where the power plug is at.

For the last three days, I've been getting the fault code P06DA00 along with a P0299FA. My car has been going into limp mode and giving me a CEL. I clear the fault and it goes away but it's been doggy so I've been trying not to drive it.

Before finding this thread, I called the dealership, they said issue is somewhat common and that it would cost ~ $3,500. I really need to find where that plug is on my car. I don't want to pay $3,500 if I don't have to. After getting that news about how much it's going to be, I started searching to see if there's an alternative to dropping the sub-frame, pulling out the oil pan replacing that plug/harness (whatever the dang thing is technically called) that's causing the fault code. They said that dropping the sub-frame is ten hours of shop time. What the heck!?! I cannot believe that Mercedes thought that putting this harness in a hot oil pan was a good idea.

I am no mechanic but I have a very good friend who is a VW mechanic. He has a lift and can pull the plug for me, but he's not as familiar with MB's as he is VW/AUDI's. Could someone, please, have pity on me and help me locate the right plug on my car so that my friend can perform this for me? I will be eternally grateful for advise.

 

For the turbo underboost,

For the oil pump solenoid code, you can watch Kennedy's video


and

With those three videos, a mechanic friend, and the proper tools, you should be back on the road.

ADDON: ignore the audio, complement the videos above

 

Give your mechanic friend this link : https://www.pvv.ntnu.no/~syljua/merc/M274.pdf


.




Good luck.........

 

OMG, thanks so much to both JCM_MB and S-Prihadi! I'll watch the videos and send him both of your posts now.

 

You have a 100kMi 4Cyl. Turbo M274 that limp-modes with a collection of faults including :
-1- P0299FA low boost !!
-2- P06DA00 the lucky failure of pump harness.
This is an unusual combination (unrelated issues).

You are correct this post should not be posted in this EXPERIMENTAL thread.

The non-profesional opinion I can share is not to rush into upside-down repair blindly.

Consider total repair cost vs. value.
At this point your 100kMi vehicle may not be worth going forward with any repair.

Consider the busy harness repair as last *AFTER* you positively get the engine assessed and low boost issue diagnosed.
Does that make practical sense?

> Engine Condition:
The first step is to get your MB specialist to evaluate your cylinders status.

One Cyl. may have developed terminal scoring damage.
Pass/fail a quick simple test of engine compression and bore scope right now, not last step.

It doesn't make economical sense to invest in repairs of a failed engine block.
Engine or vehicle swap may be a more viable route.

Your local MB dealer can guide your vehicular needs.

 

Yes, your feedback makes complete sense. Thank you for your thoughts. I'm worried about the low boost too. I'll see if my friend can perform that test. He has VCDS but does not have Xentry. I have a fairly robust iCarSoft Diagnostics scanner. It may have the ability to perform the test you reference.

Also, I don't know how to do it but if possible/desired, please feel free to move my post to a new thread. Again, sorry for posting here.

 

Emailed them 18 days ago. So far no response.......

 

Today we get to listen to how my 75kMi M276 cold starts on MOD-X(M1:"Supercar") after 26 days unused...long crank and dry rattlings, right??

Attached: MP3 1mn recording.

I made sure not to taint the crank test:
No priming, no tricks... just straight 55°F cold dry crank.

I was curious so I recorded the sequence expecting some rattling from heads drained over 3 weeks. Dry tensioners + phasers.

> Here is the timeline:

• 0 Sec dry rail crank [8.8s]
• 1 Sec GDI start-up [9.8s]
• 10 Sec gets first Rpm drop [19.7s]
• 7 Sec gets second Rpm drop [36s]
• 26 Sec gets low idle [62s]
• All under 1 mn after dry start [8.8-1:02s]

That's a lot of good I did not expect:

1. ONE Second crank to start-up
2. The HPFP primes piezo injectors instantly
3. Absolutely Zero rattling from drained heads - Not one single knock.
4. Smooth low idle in 54 Sec. runtime
5. Ready to shift without a bang: I'll take it!

> Power was disconnected:
Both Main+Aux batts were disconnected and floated before service resume. That's a valid chassis reboot.
I don't think engine crank position is saved without a power source.


> EXACTLY SMOOTH TIMINGS:
The stored precise timings enable smooth performance regardless of dry cold start.
Specifically the lack of clunkiness on a dry engine is from predictable contributions.

The absence of vibrations from smooth rotation is unsual and very noticeable. Sealed contributions are an attribute of strong powerful response.

That's Bosch advanced optimizations, available to all.


Next is review of M1:"Supercar" oil upgrade: a greater lubricant!

 

Some interesting stuff concerning engine oil grades and how laws and regulations determine oil selection by manufacturers. As has been said time and time again, don’t think lightweight oils and long change intervals have anything to do with the health of the engine. (By the way, I don’t agree with everything presented in the video but do agree that manufacturers make decisions based on things other than engine longevity.)

 

 

The video comes clean with the gasoline saved by lower viscosity lubricants:
a wopping 1% mpg savings.

This insignificant number may be appealing for commuters but arguably less so for heavy chassis with performance engines.

Lately all top car manufacturers dealing with W20 oils are getting engine recalls and class action suits: Ford, GM, Toyota, Honda... MB?
(Survey : "car complaints dot com")

Dirty machining is blamed for failures while the ineffective lubrication is kept under wraps:
limited pump output + limited pistons sprayers + limited viscosity = limited engine longevity.
That much is clear.

The comon failures are connecting rods bearings can hardly tolerate hot thinned oil under heavy load.
An effective oil film has NO REPLACEMENT with chemical friction modifiers. Viscosity has limits when power forces are involved (W20 for tiny cars is fine).

If I reference my experimental oiling upgrade to disable pistons heat accumulation. I note the stock M276 oiling is setup to deliver extreme engine heat.

No need to research how to prevent the mysterious LSPI destruction with special API-SP oil when pistons are purposely kept glowing dry... not a fluke!

No oil can wistand uncontrolled heat before vaporizing. So clean burning formula must be used to delay cats contamination.

Engineering so much drama to save 1% gas replaced by burnt lubricants makes no sense when powertrain driveability is sacrificed.


no saving + no performance = more appealing ??

 

Time flies, and I have now purchased Motul 8100 POWER 5W50 (API SP) instead of Motul 300V 5W40. I will change it soon, and by then it will have done a total of 8,500 km and exactly one year since the last change.
So far, I can only say the best things about Motul 300V, especially since I've only had to top up the oil once (approx. 300 ml) over this distance. During this time, the car was driven at speeds of up to 290 km/h (in Germany) and was often driven in a sporty manner. Therefore, the oil and the engine (with the oil plug removed) were tested for stress.

 

@slobo
You have enjoyed stable oil viscosity with Motul premium 300V lubricant. This has allowed to begin cleaning your leaky rings will less vaporized PAO oil.

The next journey step will allow more of the same rings cleaning to help the ECU tune your self-improving engine. It's simple and very effective.


> EXPECTATIONS...
As you are about to upgrade from Motul 5W-40 to 5W-50 note the viscosity upgrade will not be a usual oil change.

Mismatched engine timings will cause pistons pings - You do NOT want to muscle through any pingings ("Italian tune-up" will ruin this) - Go piano!
Simply provide an ECU fault-reset so it's forced to relearn fresh timing data over 500Mi.

It's not the viscosity that will bring great changes, it's what the engine-ECU do with it.
Powertrain will respond worse with pings and goofy gear selections before it becomes great with snappy throttle & light chassis at 900Rpm.


> QUICK PREVIEW:
If you like a simple preview before complete old oil change... right now is a time you can experiment viscosity with old oil.
you can add 0.5L of fresh 5W-50 into your old 5W-40.
Engine will clearly respond to that small amount of viscosity change.
You can have fun playing with viscosities mixing like-for-like: Motul PAO W40-SP with Motul PAO W50-SP without fears.
Don't overfill crankcase.... remove one Liter of old oil to add 1L of 5W50.


> A1 TARGET...
Welcome to stable GDI timings transformation:
Little by little as engine keeps self-cleaning, the ECU will learn best engine response where lean lag used to weaken response below 3kR.

Throttle will gradually become pressure sensitive: precise & strong.

Tranny will learn to match precise throttle after ECU improves - So tranny progress will always trail engine improvements while self-adapting. Initially some quick reset will help it relearn.

When compared with previous steps, no question what throttle response is best. The GDI ECU thrives with stable crank timings.

This experiment prooves the powertrain firmware is not compatible with stock setup.

 

If you could remember, when I made my last oil change and when I reported here, I was filling 7L of 5W40 and 1L of 5W50 from the beginning. And when I was filling up the 300ml after 6000Km, I put 5w50 inside. The oil looks after 6000Km really perfect. Like Honey. 😍

So I think the engine was pretty good prepared for the swap to 5W50. This time it will be the 3rd oil change since unplugging oil solenoid.

My plan is to change the oil and after that, we will made a trip with the kids for about 100Km in one direction and 130Km back. So the engine will gets a little bit time to learn to handle the new viscosity and made some adaptations to the timing. 😀👍🏻

 

In a similar type of turbo engine design... we can go on a limb and look at top design choices and how they are helped to fail.

> GREAT PISTON COOLING
Toyota is using a large geared oil pump, simple and proven reliable with fewer parts.

They have awesome twin squirters per cylinders to prevent single-squirter as point of failure.

As a result pistons are well cooled, oil does not burn so rings are visibly kept clean and sealed.
I translate this as "balanced contributions" !!


Eric ("I do cars") analysis points poor oiling as root cause: agreed!

The failure came to this engine from thin oil friction that welded 2x main bearings by frictions. Master Tasos shows us the same results in hot UAE desert location...

-- Conrod bearings were worned out but working

-- Engine heads were working ok but showing signs of borderine lubrications.


As for us, while we are not dealing with the same thin oil issue, the stressing forces are beared by the same surfaces:

• 4x crankshaft mains
• 6x conrods bearings
• 24x camshafts rollers

Friction issues are still very much center stage in engine wear.