> SAE:5W50 PAO DELIVERS....
The MOTUL: 5W-50 API-SP PAO is a really effective performance lubricant.
It's trustworthy oil. A robust match for tough GDI engine duty. I takes the heat without thinning out towards W40's.

This MOTUL PAO does a great job to :
effectively spray cool pistons
reliably position VVT
clean and seal pistons rings

-- Switching to Motul:5W-50 enables normal engine performance like not even Motul:5W-40 PAO can.

-- 5w40 is on the short edge of the fence
-- 5w50 is on the virtuous side of performance

-- Performance timings are tied to viscosity because of VVT positioning really on early base pressure.


> MEMORY LANE...
Today I got to re-read the initial thread when we got focused on the low pressure solenoid.


53kMi initial test drive unplugged!


Motul PAO 5W-50 was started since 65.5kMi


Now 73kMi so MOD-1...X: total 20kMi journey

-- Total of 7,500.Mi on "MOD-X: 5W-50 PAO" lubricant.
-- Literally 1/3 of 20,000.Mi MOD journey on 5-50
-- It's now a pleasure to drive that strong & nimble powertrain. It accelerates instantly and slows down quickly too.


> CLIMBING UP PINNACLE...
Every time the engine setup is improved the ECU rewards us with stronger performance.
It's the opposite of stock lean penalties

Both limits "lean vs. rich" are not real far a part with a non-drafty engine. Just need to give time some time on PAO.

Help the ECU enable your pressure sensitive throttle. Only GDI can do that instantaneous torque punch. The response does not need to climb up Rpm.

More power with less heat for free: I'll take it.


> COOLANT HEAT MATERS...
This week I started to experiment AUX-PMP: ON.
I soon realized the factory engineers left it DISABLED on NA engines to "save gas" right?

That explains exactly why Bank2 tend to store heat by hardly circulating the coolant at "normal driving Rpm".

On TT I believe AUX-PMP is plumbed to circulate charge intercooling, not engine block coolant - It's easily enabled through the F-SAM variant coding menu.


Activated while chassis awake...


Whatever you can do to circulate heat out from your engine will help your oil viscosity keep your cylinders timings predictable.... for richer maps!

Enabling AUX-PMP directly registered an appreciable difference so I decided to shade light on the HEAT chaos factor I had been suspecting.

AUX-PMP circulates Bk2 heat passed the Temp-sensor that then becomes more realistic to control T-stat opening + radiator Fan.

That's one more reason not to blindly trust "salted numbers".
The liar-gauge is based on a liar-sensor.



> No Stone Unturned...
The preliminary outcome is now engine heat is significantly lower towards normal.

Heat removal with the main pump is pretty slow so it's our best interest to keep up unlike stock accumulating coolant heat (never mind dry-pistons here).

The Temp sensor was screwing up the remote controlled T-stat function with false measures

A working T-stat helps regulates engine operating temperature. It's now far from stock vaporizing stock oil and bursting coolant leaks.


++++ MAN-MADE HEAT TROUBLES... LSPI!
Everything is done to force these engines to accumulate heat up to extremes witnessed by fan spins in winter.
I am getting my fan not to always spin in summer based JIT heat removal... remove heat while driving not at traffic stops!

The target is regulated predictable engine temps.

 

Another anecdote for the record books. Picked up my dream 2015 wagon from cars & bids last month with 36k miles. Drove 300 miles to family on 4th weekend and decided to do the unplug while there as I don’t have a driveway or space to jack it up at home. appreciate the forum advice on being nice to Airmatic.
The clip did NOT want to come out and required some… coaxing. Anyway, got to drive the 300 miles home as a nice A/B test and truly a night and day difference. Smoother start and idle, less vibration through the wheel under low load, heats up faster, throttle response better, and some (though not all) of the small rattles I felt over rougher pavement calmed down.

Next up is cam sensors (1/4 leaking oil, ECU is fine, magnets are ok but will do sacrificial pigtails.) Really appreciate this community!

 

Your low mileage engine helped your ECU start responding immediately with improvements from your better setup.

Your wet rings provide a better compression seal that smoothes unstable stock timings. Wait there's more .... you're on a virtuous slope!

Next up will be matching TCU improvements as the engine throttle response firms up.
Gear shifts will be normalized to drive 2000.Rpm instead of 1000Rpm (5th gear at 25mph!)

You simply need to help your computers enable "normal" performance. The bleeding edge is super thin. It take stability to stay on top.


In addition you can experiment complementary technics:

1. Effective oiling (grade + type)
2. Stable chassis voltage
3. Whole chassis reboot
4. Specific CGW reboot
5. (Stable heat mgt)

They all lead directly to something of top interest : strong response with smooth driveability and controlled heat... a superior Mercedes ownership!


> More reward to celebrate:
-- Based on exact timings the strong response above 3000.Rpm is noticeably not clunky under high-load, unlike stock with freaking noisy skirts under load.

Everything that helps exact timings yields more efficient engine output.


++++ Paradoxal translation....
"Heats up faster"... actually means cools better!
Say goodbye to accumulated heat with MOD-X.

 

5W-50 Motul also recommended for the (C400) M276 Biturbo?. You guys are insanely informative and this is all highly interesting!.

 

I would not encourage you to jump to 5 50 straight away especially if you like to beat it on the streets, better option for you is to pick 5 40 Motul 8100 Xcess Gen II API SP / Motul Power 5w40 which is SP, im currently with Power before that i was with Xcess, so far i can say the Power keep its viscosity better (already 4k km old - 3months)

im sure Cali would give you more detailed answer to your question as he is more informative about this topic

 

yes, exactly !

I think it's SAFER to ramp-up your engine into more effective viscosity so it has a chance to cleanup.

Your engine may be "Mr.Clean" with homogenous compressions and you're in a hurry... then you could try 5W-50 PAO SP.
You will get improved output right away. Besides ECU/TCU mapped adaptations will be shell shocked goofy.

The key to getting reliable timings is a good seal. That means [sealed rings + oil] not [stuck-rings + oil]
Stock engine use modern low tension rings with polymeric synth oil.
That's drafty then becomes misfiry.

Leaky cylinders place too much load on neighboring cyl. that cause wear on high output load.

With sealed cyl. the stress forces are shared on all cyl. More predictable power is available at lower Rpm.

With the right setup, the stock lean misfires are transformed into pressure sensitive throttle.

Avoid pushing your engine if it's vibrating unbalanced. Help it seal.

 

Thanx I'm going to look into it!

My C400 is from 2016 and when i bought it, it had around 54k (33k miles) kilometers on the dash. It now has around 72k (44k miles) kilometers.
All oil was done at around 10k (6k miles) kilometers by the previous owner.

I'm going for 3k/5k kilometers on my current and fresh 0w40. Then switch its up with 5w40 Motul 8100 Xcess Gen II API SP.
Going to ease into it then, so no spirited driving for now. Just relaxed highway cruises.

Did notice quicker warm up, better brake booster and somewhat higher oil temp. Around 98/100C while cruising on the highway.
And i get what you mean with the vibrations at low rpm. It has it and I've always found it weird.

I'm also interested about the Alt-Lin mod. Could you guide me to the correct forum post?. I want to know more!. That said I've noticed during driving the voltage fluctuates alot.. 14,8v down to 13.8 and then back up again ..

 

with ALT you will get 14.1V stable, prev. i had same fluctuation as everyone else

normal temp when you drive normal ~100C - same as me (after i unplug solenoid)

here is the ALT topic - https://mbworld.org/forums/mercedes-...s-voltage.html

enjoy

 

Awesome thnx mate!. Did you also do a Float and Reset, or just unplug the connector?.

 

just unplug since we dont have 2nd battery as other members in the trunk

 

Oke nice. Still going to disconnect the batt to reboot the car. Just read through the ALT-LIN forum. Its stretching my brain!, all the terminology, graphs etc!. Phew but so interesting to read!.
Btw, what did you do to your car to get it too stage 2?. And how much HP does it make?.

 

you can experiment with disconnecting it im not really sure if will have any improvement only with that

im with catless downpipes and bms intake with remap, on dyno put out 427hp and 650nm, i think thats on engine not wheels

 

I apologize if this question has been covered earlier. When we unplug the oil pump solenoid in an M157, oil pressure goes from 2bar to 4bar at all times. So the piston cooling jets are active.

Question - when pumping oil to piston cooling jets at all times, are we sure that the main bearings are still getting the same oil flow? i.e., are we sure that main bearings aren't starved at idle when oil is being flown to piston jets?

 

No. The pressure increase linearly with RPM from 2bar up @4bar. Piston cooling jets activate as the pressure increases , i.e. engine speed increases.

 

I think it helps to understand how the solenoid works when normally connected:

Under low rpm/load conditions, the solenoid is energized, activating the ‘reduced flow’ mode - which yields about 2% better economy & 2% lower emissions.

Under high rpm or high load conditions, the solenoid is de-energized, providing the full flow/pressure of the oil pump (in Germany, these cars run hours at a time under high loads on the autobahn, so I’m confident that MB has engineered the oiling system to work properly under these conditions).

Unplugging the solenoid doesn’t create a ‘new’ condition for the engine, it simply prevents the oil pump from going to the low pressure/flow mode.

With the solenoid unplugged, the oil pump works as every other oil pump did prior to these fuel/emission-saving ideas.

 

As JCM points out: the pressure increases linearly on a different slope from idle towards 60Psi Max.

At idle there is not enough pressure to activate piston squirters near 25psi.
All bearings are supplied in priority by pump pressure.

MOD-1 solenoid:OFF enables the normal pump volume as opposed to a more limited volume to "save gas".
The pressures outside idle are similar to stock. A higher viscosity is necessary to experiment spraying more effectively than stock at "normal driving Rpm" around ~1750Rpm".

The stock 5W-40 cooling Rpm is still above the "normal driving" speed heat can get accumulated once oil is heated up or aged.

The sweet spot is right outside of W40 range.


> THERE'S MORE: **** DRIVEABILITY PERFORMANCE****
-- It's no secret: the W212 CAN network is unstable. There's a quick workaround relief for that.

-- Look into experimenting a simple "chassis REBOOT" then the even faster "soft-reboot" by scanner/xentry without any Batt. disconnect.

-- You will see right away how your ECU/TCU gets unlished!

-- That procedure further enhances driveability response in PARTICULAR TRANNY SHIFTS.

-- ECU/TCU "Fault clearing" are NOT reset at all - Only support modules get refreshed.



precise hydraulic computations

 

I have a 2020 GLC 63 SUV. I'd love to verify my oil pressure manually. Is it possible for you to post the directions?

 

MY:2020... Look at sourcing a cheap dummy-load to cancel CEL.

The pressure sensor port is located near the base of the oil filter: 12Psi Min straight up to 60Psi Max.

> Pump pressure Testing...
Sweep RPM from 650 to 2500.Rpm
MOD-0 Stock
MOD-1: 5W-40
MOD-X: 5W-50

Find the various Rpm that produce 25 or 30Psi.

 

2020 with 42k miles

 

Yeah that's the plan. Sorry I edited my original post. It's a glc63 SUV.

Is it just the removable center part of the oil filter cap? Do you know of a oil pressure gauge that screws right in or a kit that has the right adapter?

 

40kMi: your rings should clean up rather quickly.
🤞

stuck carboned rings @ 30kMi on 276

Here is the Turbo M276 tour courtesy of...

 

https://www.63motorsports.com/

 

here's from the WIS

 

Wow, thanks for providing this! It's extremely helpful!

 

Stock provides the following oil pressure:

Engine M176/177/178 oiling

> Stock oil pressure scale:

• 650R : 15Psi is Min pump output
• 1.75kR : 22Psi accumulates heat
• 2kR : 30Psi is remotely effective spraying
• 3.5kR : 50Psi solenoid switches to normal pressure
• 4kR : 60Psi is Max. pressure relief

- The key is to hide the pressure drop of squirters opening low enough to still get effective spraying around 1750R driving
- Dry pistons accumulate heat that burn oil carbon into rings groves.
- Stuck rings detune GDI engines timings with lean misfires.