I will check both coolant levels before the trip.
I have completed the Reboot & float.
I planned on doing both again right before the trip.

 

Hi guys. New to the forum. Can anyone post a pic of the location of what i need to unplug for the oil pump mode for M278 on a GL 550?

 

@W205C43PFL can locate best threads to find answers.

Optional CEL-dummy solenoid made possible by @JettaRed own research and experimentations.

Next question will be what 5W-40 oil upgrade to begin with?
Your choice of available "MB Approved" "API-SP" rated or better.

My personal favorite oil recommendation by @JCM_MB is Motul Xces/Pwr 5W-40-SP: provides robust PAO viscosity.

Also Castrol, Penz, Mob1... are known good synt. oil choices.
0W-40 limited viscosity is best for frigid winters.

@ChrisHimself registered Amsoil dealer and MBWorld sponsor

Am.SS 5W-50 API-SP PAO 👍
Amsoil order delivered at your door in 2days by UPS.


There are really no bad synthetic oils.
Some rank better than others based on criterias:

1. MB Approval: Y/N
2. API-Rating: SN/SP
3. Viscosity! 5W40/5W50
4. Group III/IV: Synt/PAO
5. Useful lifespan: 2k/5kMi
6. Retail availability/pricing: ~12Ea Qt.

MOD results vary based on available oil pressure to prevent VVT surges + clean dirty rings + seal low tension rings.

 

search keywords "278 dummy solenoid"...

Here a thread to read

FYI: my harness plug is simply zip-tied down.
No CEL, only fault NOT reported active for SMOG check.

 

Thanks for the mention : )
Let me try my best: https://mbworld.org/forums/attachmen...850d1704906443
See page 25 of that PDF, same exact location as the M276 it seems.

 

Monthly special at the localish NAPA. Though the picture shows SN on the back, I would think its an old pic since that oil is now SP. I looked at it last time I was there but dont remember cause my goal was the 5/50, Might be worth a call.

https://www.napaonline.com/en/p/PEN550051120

 

Its made with Shell's proprietary "natural gas" synthetic process.
The price-point is really selling it and it's also SP rated.

See how your engine runs with it.
It's a good lubricant.

 

From what I understand all the oil brands buy base and Lubrizol additive packages. Pennzoil's base oil is made using the Gas to Liquid process is explained here. It takes something we'd normally consider a byproduct and we get delicious oil out of it. If I wasn't part of the cult, I would be using Pennzoil for its availability and what I've seen on used oil drains.. It barely costs more if even then Castrol Edge or Mobil1 Euro which is what I was using for most of my life.

https://blog.amsoil.com/is-motor-oil...al-gas-better/

Amsoil doesn't MAKE base oil, only the refineries do that. I've read Amsoil shops around, which could be one of the reasons they do not have an API certification since the formula isn't constant. That means Amsoil is probably a blend of Mobil/Exxon/Chevron base + Lubrizol add-packs and that blend is what makes the difference I guess.

 

Great price ($7.49/quart)! That's a few pennies less than Amazon and great that I can pick it up locally. I should check my inventory.

 

yeah, the price is great. They have monthly brand based specials and each of the synthetics reach these low prices. Albeit Pennzoil is not a cheap as bulk Mobil at Walmart, it’s a better choice imo. I’ve not seen low local prices bulk on Pennzoil euro. I use Platinum in two older landcruisers and really like it.

 

Runs very smooth and quiet with slightly reduced idle RPM. I also experienced the no crank starting.

Nothing shiny in my old filter, just a little bit of carbon in the pleats.

 

Ok I have 400 mi. on the 5w-50 Motul as well . I noticed slightly reduced idle but just figured I was making it up in My head. I also went back to removing the noise reduction foam under airboxes. I didn't notice any extra noise with hood closed and air intake temps were 15 degrees higher than OAT at all times except slow moving traffic. My car never took more than a second to start before so not sure about crank time.

 

> No-crank starts...
Engine always starts up really quickly once the HPFP has pumped 2500.Psi in the injectors rail for GDI.

When engine is warmed up, if you stop for 20mn, then rail pressure is already available and ECU recalls mechanical position, it is then able to ignite with just a fraction of a turn by getting a cylinder into compression, injecting fuel into it and firing the mixture.

The day stock ECU decides to perform this new trick.... you will notice zero-crank start-up
Not getting it, means engine needs further improvements. It shows up has a bonus.


The cold start sequence with elevated Rpm gets shortened too. ECU lowers Rpm much faster as soon as it gets positive control of VVT and HPFP. No way Lambdas are already in "closed loop".

Paying attention, I do notice a short 2Sec. light knocking right before droping to low idle.
I think thats the HPFP prop-valve synchronizing with 3x camshaft lobes.


over extended a bit 5,800.Mi


good looks, not carbonized : PAO
still clinging well on the stick after 6kMi.
stable VVT positioning


normaly shape round filter (not smashed flat: LOL)


bypass valve wash: CLEAN!


solvent rinsed off with old oil


transitioning 5w50 : MOTUL PAO to AMSOIL PAO

I ran Motul 5w50-SP for 5,8.kMi straight:

Absolute most stable oil performance. I will happily reuse exact same one next round.

Available viscosity did not age out of spec to mess up VVT mapped positioning.
(No need to blend in experimental booster shots)


> I only have 30Mi on Amsoil 5w50... so far similar to Motul 5w50: stable viscosity enables early stable VVT Mgt without surges.

> MB engine likes being serviced:

1. 7x Quarts of oil vacuumed out
2. Reboot while oil is being replaced
3. Float main battery while disconnected
4. Clear all faults

> Consistent engine performance regardless if cold or running temperature (VVT on 5w50).


> UNBELIEVABLE GDI THROTTLE:
-- I got back the amazing pressure sensitive throttle that pushes the car right from idle with the same force accelerator is pressed.

Torque is available without waiting for higher Rpm. GDI magic for ya.

-- Same amazingly precise throttle at Hwy speeds.


> ENGINE HEAT :
> Let see how the heat management goes with Amsoil once stabilized in 1kMi.

-- No question engine can get hot !!

-- Can heat control stay normalized with mapped Tstat ??

 

I have a vid of start up with fresh 5w-40 Sn and fresh 5w-50 SP. I'll make one at say 1000mi with the 5w-50 and see if there is a perceptible change.

 

I am back from mbworld hiatus due to school + finals + work compounding me, i have been only driving but noticed from my post prior that i thought intially there were many benefits from going solely to 5w-40.

Anyways, I kind-of forgot about everything for a while but recently, 5k miles have passed for me since the last post so I have revisited the topic of oil viscosity.



So, I stayed at 5w-40 and stayed with LiquiMoly, but went from LHT 5w-40 to TopTec 5w-40. I doubt there's a difference there.

See the picture below, my oil is still burnt looking and doesn't look good. It looks more indicative of oil degrading and shearing too fast, my oil temps were somewhat unchanged but no major difference at all in overall warm-up time. I think that has more to do with the behavior of the M256 more than anything else, but the main point is, Mod 0 is still in effect. No increased oil pump action....!



Please ignore the rudimentary crowbar. My ramps aren't big enough and the screwdriver wasnt thick enough to get to the plastic drain bolt (lol).

Anyways, here's a unique caveat (and i will probably get sh*tted on for this.)

I didn't have enough 5w-40 ordered for this oil change- my dumb *** just oil changed my Lexus RX350, and it didn't stick in my mind for some reason that the M256 has a higher oil capacity when I was ordering from FCP Euro. (2GR-FKS V6 has a capacity of 5.7L.) So.... I had to dilute. With 5W-30 that I have at my house.



6 Liters.

2 Liters.

My overall oil is now sitting at 5w-37...? So now obviously I need to remedy that. I did set the service to 222.51.
Flame me for being the stereotypical 2nd owner.
Anyways...

Remembering that Oil Viscosity may enable the piston squirters by themselves, I decided to be adventurous.

I added two whole 300ml bottles of viscoplus!

I honestly couldn't tell you what my math is for my oil viscosity is now! Someone do the math for me! Remember that my total oil is now at 8.6L.

Anyways, now that my oil is now sitting at an insane viscosity:



Regular temps that I'm usually at is 210F...
220F with good highway driving.

Is my piston heat being removed?
Did I just find the most ghetto solution to MOD-2? Without even doing MOD-1????

I would unplug but there's just too many variables with the M256 I don't know about.



(deciding to show off the selection of S class wheels here. Decided to copy my dad who has these same wheels on his s580.)

 

Car looks good, welcome back, yes I will hold off with the oil pump solenoid mod on the M256 for now until more data is available.

 

on coming back, I realized there are some threads about the oil temps reaching 230 and 232 even at lower viscosities - but 53-line owners are reporting this at lower viscosities and even in comfort mode in around-town driving. I wonder if something else completely unrelated is just causing the temps (it is like, 85f in southern california right now), or if i shouldn't be expecting this kind of behavior from freeway driving.

 

If you're stock plugged-in aka. MOD-O then your oil pump is supplying limited volume until an ECU condition gets met to deactivate the solenoid.
Then oil pump is shifted for normal output pressure. Usually unde load or above 3500. Rpm

The driveability below 3500.Rpm is disabled by limited surging oil pressure.
As far as mixing oil: you have 3 types blended together. Its hard to forecast the result.
5W30 does not belong to this engine unless you live in Fairbanks Alaska.
2x bottles of viscosity modifiers is a lot.
8+L itera may be higher than the upper dipstick mark. Don't drive overfilled. If you stamd by your blend use it else order an Amsoil UPS deliver, 2 days.

API SP is the better stock oil to use. SN is getting phased out.


To summarize your specifics:
you may be better off switch to "MB Approved" engine oil ASAP on your stock MOD-0 engine.

What the ECU needs is stability it can work with.

 

5w-30 is prescribed to m256 by dealers for what i assume is fuel efficiency. even in warm southern cali.
they even prescribe it for the m176 v8.

the normal mark is 8.5L so I am overfilled by .1L.

API - SP... i don't get what the abbreviation is, could you point me to what I should get next time?

once i become brave enough to diy-install a oil pressure gauge, i will truly take the first hit and become the first m256 solenoid unplug.

 

I should pick up a couple of bottles. That price on Amazon is if you get a six-pack and not individually. I checked my inventory and I have two six-packs, but use about 7 quarts for each of my cars. Therefore, two more quarts will give me two full oil changes. Thanks again for telling us.

 

I believe the 5w50 will step through fast idle faster.

It would be interesting if we can hear HPFP cam lobes knocking for 2 sec. right before idling down .

I think engine does idle a tad lower now.

 

need to compare with other M256 engine vehicles to be sure.

 

I don't know your M256 engine specifics:
8.5L of 5W-30 in a MB V8 engine.


Just be aware what a "synthetic Euro oil" is... it'a good lubricant that "saves gas" with low friction by spending most of its life as a heavy W20... GM is dealing with a legal mess about low viscosity V8 on w20 spinning bearings from thin oil!

Don't use extended drain interval.
It's better to use "severe duty" shorter service interval.

Viscosity cut both ways: not too little and not too much.


API-SP: is an industry standard for Spark gasoline engine as oposition to Compression diesels ratings.
SP vs. SN formulation is to protect by helping oil not to blow up piston during self igniting dirty oil...


To experiment MOD what is really surge-free oil pressure :

1- Step free pump output volume/pressure. MOD-1

2-- Effective viscosity to position VVT gears and cool pistons MOD-4

Your M256 may react differently than other engines we've tested MOD-4 with. VVT Gears may or may not be bothered by oil surges.
Do you have the laggy throttle response ??
High engine heat regardless of Fan:ON

+++ MUTUALLY EXCLUSIVE...
I dont think you can test engine running on stable oil pressure with active pump solenoid disabling normal pressure.

Don't mess with viscosity on MOD-0

Upgrade step by step for experimentation
ECU GDI timings are very sensitive for upset or improved.


> MOD Application Questions are...
-- Is throttle response laggy and tranny confused??

-- Does engine store extreme heat with FAN invariably always On ??

-- How would you describe idriving under 3000.Rpm ?

 

Is AMS that everyone recommends SP? liquimoly is only sn.

VVT in the MB double charged engines are more or less acceptable - in m176 and m256 the 48v system and electric supercharger demands that the vvt is always supplied correct pressure, so there's two pumps - the split oiling we talked about back in thread page 116 or so. IMO there's not much improvement to be made, especially if you ask me between the m278 (i used to own a r231) and the new 256/176, the responsiveness is much better.

Fan will turn on at 215F+, you could probably ask most 256 owners.

Driving under 3000 RPM is fine in terms of responsiveness. And plus based on engine failure data (which almost none is available since engine is new), scoring and leaks haven't popped up as big issues yet
I did find this:

Yay RMS! I feel like most of the recalls so far about the m256 were about it's 48v system, goodness gracious there were so many recalls for our gls 450 and s580 throughout the last 4 years.

 

it sounded like those situations had to do with comfort mode - the idle there is only 500rpm