Googling "what temperature does synthetic motor oil vaporize" produced an answer of around 300°F. My oil temperature stays between 198°F and 205°F, sometimes reaching 212°F. Piston skirts reach temperatures generally lower than the piston crown, with studies showing skirt temperatures can be around 106-165°C (223-329°F), depending on factors like piston design, cooling methods, and operating conditions. While the piston crown endures extreme combustion heat (over 250 °C), the skirt, located further from the combustion chamber, experiences less intense heat and functions to transfer heat to the cylinder wall. It appears that under normal driving, skirt temps are not going to reach evaporation temperatures.

 

There have been some fantastic responses in this thread. The more I learn and discover about this "modification" the more inclined I am to take the leap and just do it. With everything I have read, and my (overall limited) knowledge of motor vehicles and engines, I cannot see why it would be more harmful to the engine in freezing temperatures with this mod allowing full oil pressure at any given RPM.

 

here we go again.....

 

Engine start is always carried out with unlimited "high idle" pump pressure... like 25psi either stock or upgraded: no difference
Until lower idle: active solenoid drops pump pressure into the weeds...
until you hammer the gas pedal or eventually run above 3500.Rpm solenoid allows normal oil pressure.

That means at highway speed near 1800.Rpm your engine has limited oiling pressure and limited pistons cooling according to your own prefered setup (MOD-0/1/X).

At frigid Canadian Winter temps you best not use basic sludgy oil.

Use an "MB Approved" PAO oil such as MOTUL 5W-40 API-SP or better: double check the charts exactly!
This PAO lubricant should give you more reliable engine oiling than a high polymer economical group-III.

Not everyone cares about good oiling... some ppl change oil every 3k.Km other annually or at 10k.Mi... the amazing 20,000.Mi is an engine destroyer.

Do keep an eye on how much oil your engine is vaporizing out - This will be interesting as time goes: increase or decrease ... your guess??

Go ahead research around including from "Bob is the oil guy"

There are no bad oil, only cheap oils you can change more often.

Don't use "oil additives" shots... instead use better oil to begin with.

Enjoy your experimental choices.

 

Let's also be clear that "full" or "normal" oil pressure does NOT mean MAXIMUM oil pressure. The minimum oil pressure occurs at idle and is not 0 psi. Maximum pressure is approximately 60 psi (4 bar). The rise in pressure is nominally linear from 650 rpm to over 3500 rpm, with the solenoid unplugged. With the solenoid plugged in, the pressure is capped at ~30 psi (2 bar) until it reaches 3500 rpm and jumps to max pressure. That's the observable behavior of this mod.

 

 

Always one

 

well played. Make sure if you have time to report back your experience once unplugged so we can get more anecdotal experiential data. Things like drivability, idle vibrations, shifting smoothness, etc.

and the thing that everyone seems to agree on, change your oil every 5000 miles.

drive safe

 

I believe the consensus was that during the start up sequence on a cold engine, the full oil flow is present anyway. You can reference the main solenoid thread for this information.

I think choosing your oil type wisely is probably more important in subzero temperature startups.

 

I am pretty religious about more frequent oil changes, I guess that is one good habit I have picked up over the years. I will be unplugging and wrapping up/blocking off the solenoid connector on both ends this weekend, and will report back.

Currently, the car does feel pretty "slow" to react to throttle inputs. I don't personally expect much of a change here, to be fair. After all it is a 4300lb vehicle - but hey, I'll take any sort of improvement.

Transmission is very smooth already, and very snappy on up shifts and down shifts, which was pleasantly surprising. I do not expect much difference here.

Occasionally, I experience a "shake" when stopped at a red light. It is very mi nor, but feels like a misfire, although the RPM needle stays smooth in the normal idle position (500-600rpm) and does not sound like a misfire - simply just a minor shake. I would be curious to see if this is improved by this mod, but again, not expecting much here.

I will be sure to report back with what I notice, even if nothing at all, this weekend. My vehicle is a 2015 E550 with the M278, and I have about 31,000km (19,000 miles) on the vehicle. I just did a fresh oil change about 400km ago using liquimoly.

 

reset the tcu to gain some of that throttle sensitivity back ... Google "tcu pedal dance"

only 19k miles on a 10 year old car! Wow

 

Yes quite a rare find I think. I have some minor issues with it like the dynamic seat is not working (narrowed down to either a leak in the lines or pump not producing enough pressure) and some minor issues with the dampening on the air suspension. But I imagine the car spent a lot of time sitting on the suspension and that caused it. Overall happy with it and will be taking care of all the issues in the next few weeks. Hoping it lasts me a long time.

 

I had a 2014 e550 and absolutely loved it - I had trans issues and Benz bought it back but it was otherwise an amazing sleeper

also, I bought a sprint booster for the throttle and for me it helped tremendously

 

Great reporting format - Keep tracking these same distinct entries. Also note Mi/Km distance and engine oil consumption.

It's a positive sign your tranny shifts were not impacted to begin with. You still at the stage of a mild case.

> BEFORE you begin your MOD experimentations be aware that :
-- re-plugging pump solenoid carries a risk of it jamming with accumulated metal debris. Perhaps as low as 1% nobody knows and no one likes to get a dry engine blown up ie. RIP...
-- This is NOT CASUAL fun... I do not recommend anyone doing something they don't individually understand, not based on personal opinions inputs, that are non-professional, non-advice, by non-certified, from non-qualified members - WE'RE ALL NUTS.... welcome in!"

You are already religious about oil, so are some of us now! These engines literally thrive on hydraulic pressure remaining stable.
Stock frictions lube is already not bad for normal driving with 5kMi. oil. Modern oil blends are extremely effective at molecular levels. There are no bad oil thanks to... Lubrizol scientists.
There are good Group-III synthetic stock oils and much greater Group-IV poly-alpha-olefin stock oils... aka. PAO's.

With that said... I am oiling with a stable 5W-50 PAO API-SP (AMSOIL now) and would not have it any other way than a W50 viscosity for timings purposes.


> MOD-1 LIMITED INITIAL STEP...
You should get a really small initial improvement in the throttle response with less lean lag hesitations after a period of 1500.Mi learning mixture adaptations.

More pronounced will be driveability improving a bit around 2000 to 2500.Rpm when MOD-1 oil pressure is stabilized after squirters opening.

> AMAZIN' MOODINESS
You should notice modiness between warm and operating temp after 1700Mi.

Observe that engine cold /warm responds much better than when fully warm when it gets heavy with lumpy response.

Everyday on fresh oil for 1000Mi you can notice this transition from good perky to poor slow poke.
Only 15mn of good, guaranteed slow poke after 25mn.
Aged polymer 0w40 oil has little viscosity effectiveness left as it behaves like 10w30.

This moody engine response is the motivation to upgrade oil. Some ppl swear by stock everything, I take problems apart looking for clues...

By the time you begin understanding that oil thinning out is detuning your engine camshaft positioning logic... you may decide to select an "MB Approved" superior 5W-40 PAO lubricant aka "MOD-2"

With MOD-2 you get the similar engine response to MOD-1 but improved enough to make you enjoy your results while oil remains newish + cool.

The only thing happening is your pistons will be kept more oil cooled at 1800.Rpm normal highway driving. That allows to clean up rings instead of vaporizing more oil into hot pistons rings kept dry up to 2600.Rpm.

This really begs for a formal "pressure vs. Rpm vs. oil grade" study to know exactly - However for the sake of simplicity the answer I found experimentally effective is a 5W-50 viscosity.

We could or should chart oil pressures to explain the effectiveness of VVT positioning depend on the interaction with squirters dropping line pressure.

It's a complex subject because there are lots of interactions involved that affect oil effective pressure (regardless of ok friction lube). Lets not list them here again...

We can sum up variables by saying this study boils down to the reliable positioing of camshafts with low error rate.
The ECU VVT logic has limited ability to handle viscosity variations (unlike trannies that track multiple temps to manage changing ATF viscosities for shifting pressure control). Not rocket science tranny logic does viscosity Mgt really well but engine does not.
We can pin point the issue on the simplistic VVT firmware control. Hardware parts are fine. Engine oil pressure control would benefit more granularity to prevent undesirable side effects. ECU logic should be made compliant with low pressure.

.....
Pls "no Italian tune-ups" with fragile equipment! Power will be made available when smooth engine timings alow ECU to gets in GDI mood. You will know.

 

Hi all,

Today has been a busy day in around the E550. Slightly off-topic, but I will share anyways: I installed new winter tires (Continental VikingContact8) on the vehicle to prepare for the winter season here in Canada. The ride sucks! They are a very soft tire being a dedicated winter tire, but they are good other wise. The vehicle feels much less agile and a little more floaty, and the steering feel is less direct. This of course is a compromise I am completely willing to live with given the purpose of the tires is to handle the ice/snow/cold until the spring season. Increasing each tire to 39 PSI helped quite a bit with the feel.

Secondly, since I purchased the vehicle, my dynamic driver seat was completely inoperative. I could hear the pump whirring and humming when getting in the car, but after a minute or two it would shut itself off. After a few weeks of procrastination, I have diagnosed the issue - luckily, the green airline was disconnected from the pump in the trunk. I think I have gotten lucky with this fix as it took just 20 minutes and cost me nothing. Wonder how it got disconnected?

Now, back on topic. While doing all of the above, I did also get under the vehicle, dropped the undercarriage covers, and went searching for the oil pump solenoid. It was a bit of a pain to disconnect as it seemed to have almost "seized" onto the connecter - but I was able to get it off. I cleaned up both ends of the plug and the connecter, did not notice any oil leaking out into the plug (also checked the camshaft sensors at the top of the engine, no oil there either thankfully)

I covered them generously in some electrical tape (might look for a better method but this seemed to be okay) and zip-tied the plug to secure it so it doesn't end up in the radiator fan.




Initial Thoughts with solenoid unplugged:

Idle: Much smoother, when in park with engine running. When stopped at a light, there is still a slight "shake" - however it seems to have been reduced by about 75%. It is still there, but considerably less noticeable than before.

Transmission: No noticeable difference in upshifts/downshifts or general performance of the transmission.

Throttle response: Massive change, in my opinion. There is still obviously some delay present, but the car is much more responsive and this is a significant improvement. Driving around the 1500rpm-3000rpm now is a lot more enjoyable thanks to the extra responsiveness.

Fuel economy: I know fuel economy numbers should not change too much either way, but I am getting more or less the same numbers as before. Pic attached on a brief highway drive, pretty good for a 4.7L V8 TT!



To keep this thread on-topic (and not to become a clone of the original thread(s) reagrding this) I will report going forward what I notice during freezing temperature, extreme cold, or whatever we will end up facing this winter. I would encourage anyone else that has done this mod and lives in colder climates to do the same thing here.

For the more knowledgable out here - let me know if there are certain things I should check/monitor data wise. I do not know much about what might be useful, but, if it is helpful - I am happy to provide some data in freezing temperatures if you let me know what would be helpful.

 

I will also be looking into the oil recommendations from Cali, too. I was confident before Liquimoly was the "way to go" but I see I have some more learning to do in this regard. Thank you all again for the abundance of information and responses here.

 

I don't sell anything and specially not PAO oils... All stock "MB-Approved" oils are good.

You know "fresh oil" is always best before viscosity thins out more or less rapidly...1750.Mi.

Decision to replace early is at your discretion: 3 to 5kMi based on fuel dilution, short trips....
Longer is not better.


One thing you can do is note your oil temperatures from the IC Display.

With a bit improved oil pressure MOD-1, oil is able to warm up faster as it is now able to spray cool pistons at a bit lower Rpm's

You should see "oil temp warmer than coolant". That means cooler pistons getting cleaner.

MOD-0 usually keeps oil cold longer tralling low as it is warmed up by coolant heat-exchanger instead of wet pistons.
Cooling is a freebie for ya beside the journey of throttle learning best behaviors.

 

Do I need to code this in to view oil temps digitally in the cluster? I have played quite a bit with the menu and cannot find this option. It is completely possible I didn't look hard enough!

 

No oil temps....
I guess you dont have the display because the engine does not have oil sensor for neither temp nor pressure.

It's kept under the radar... let's not worry about it.
Only few engines feature these sensors.

Keep track of oil mileage, oil level and oil color if you will.

 

Here... take 90 seconds to listen to this MOD-X 4000.Rpm sweep

Smooth engine sound.

 

couple items for you to consider, after having seen your method of protecting the plug and the solenoid plug receptacle.

The engine will heat up that electric tape. It will fall off and it will end up flying into the radiator fan or somewhere and hopefully nothing bad will happen, but you would like to avoid this.

Subsequently the plug will be uncovered again, and you will have no way of knowing that it is uncovered again.

We designed a method collectively in the main thread to use a pigtail harness to plug into each end, the solenoid receptacle as well as the engine, harness plug, two pigtails total and at the end of those wire pigtails, you can use hot glue or some other sealant to seal off the electric electrical end.

Also, if you're gonna use zip ties consider using steel zip ties, the plastic ones will dry up and failure overtime, particularly with engine heat exposure

review the main solenoid thread to see how this was done in depth

here's a pigtail on my engine side



second pic is a dummy solenoid I attached and sealed to prevent soft code

 

Added pics above

 

Nice - just ordered a few of those pigtails. That's a great idea. Thank you for sharing this!

 

Great method, someone also suggested RTV silicone if I recalled correctly.

 

anything is better than nothing.
mine is left wide open but zip tied nearby.... I'm an easy-Joe