Peter, you're at the begining of MOD-1.0 with very little difference so far. I wish I could hand you an ECU MOD that helps your existing tune.
Here it is: I think your special setup is focussed on top end - Me bottom end of the RPM below 3kRPM.

Your cooling is already enhanced with higher fan speed but if the pistons are kept dry, the heat stays trapped inside the engine.


There's a real debate about TT engines not being sensitive to blow-by improvements the way NA engines readily pick up on it.
Besides MAP sensor importance, the oil pressure increase benefits the HPFP timings. This can only be achieved by the hardware tensioner.

Does your setup suffer lag below 2500.RPM ??

How good is your TCU useage of gear:1-2-3-4 : long gears or short gears?


If you want to improve your heat transfer, use an engine oil with slightly higher viscosity than 0w40 is only going to spray above 2500.RPM below that heat accumulates un-removed.

In couple hundred miles your cylinders hardly had anytime to cleanup to balance your compressions.

Try MOD-2.0 to remove core heat.


So given current setup ECU decides timings are to unchanged. You can always clear faults to positively refresh ECU operations.

​​​​​​

 

So from all my reading on these topics, it seems that the Oil pump solenoid mod and intercooler pump always on should go hand in hand just for longevity purposes over anything

 

Yup : )

 

Yep, I guess you could summarize it that way: Basic Piston Cooling can be provided by better oil pressure.


Actual piston spray RPM is affected by... :

• oil pump solenoid
• oil viscosity
• oil temperature
• oil mileage

​
Perhaps I should make a visual Scale..:
RPM
1500 : 5w40+shots.... MOD-2.1
2000 : 5w40.... MOD-2
2500 : 0w40 ... MOD-1
3500 : stock dry lubed cylinders. MOD-0

Spraying pistons at normal driving RPM requires a boosted 5w40 oil viscosity. Make sure you remember that one if you are still burning oil by the quart... vaporized to PCV, not the rings.

A 0w40 spray RPM will remain higher than 2.5k RPM and oil will burn-black and engine will store extreme heat.


4000kMi oil

Lets see that oil:

4k Mi MOTUL + Mob1 (!500ml shot)
+++ also level nearly unchanged since tainted by M1 shot mix 👍👍👍

Okay I am gonna have to be satisfied with the above

I have never seen an oil that old with that appearance. Seems Motul like its mix with Mob1.

Guess that oil maybe the legendary in your dream 10k oil... I may go 6kMi based on curiosity.


++++ came home without FAN on!!!
I drove home last night, my 100A fan was not running even after parking - I could not believe it. (I have new T-stat in couple days).

I recorded more amazing idling after soldering my ESP this week - - Notice:
-- ABSOLUTELY ZERO ICK-UPS
-- Evenly Timed cycles

It runs like a bear from 900.RPM
This is becoming quite a real good car now.
Tranny oil seems to stay cooler precise and direct just the opposite of sloppy. It's super well behaved to match throttle. I had it DROP TWO GEARS at once super easily - - Yep first time for me !!

It seems like tranny now has new ways of shifting... not a dumb box at all. TCU shares strategies with ECU.

I bet proper shifts are going to be beneficial against clutch-sludge.

 

Drivers instrument cluster 45mph...

> We can see...
-- coolant liar-gauge is 15°F less than oil temp
-- engine running at 1200.RPM


> What does that tell us??
-- That means Tstat and radiator are doing a fine job at removing heat from coolant.

-- How much spraying does 0/5W40 do at 1200.RPM .... NONE!
Your pistons are accumulating unremoved heat.

-- The only path of escape is through coolant and extreme heat soaks.

I understand 5w40 "MB Approved" oil list does have trusted value.

To activate piston spray-cooling you need to manually switch gear such that you keep RPM between 2700 and 3000. RPM.

This is not very convenient driving style but as soon as the RPM drops the pistons accumulate unremoved heat regardless of pump solenoid MOD-0 or MOD-1.
If stock oil is older than 2kMi it has sheared into W30 range as shown in UOA.



turbo cooling circuit over boils

> FURTHERMORE....
You're not alone driving with stock or near stock conditions - MB-USA always acknowledges "no other car has this issues".

I believe this engine has an oil Tstat right?

Oil Tstat would be a great maintenance item.
We would expect it to fail open... perhaps it's now stuck partially open - It has to open/close smoothly.

I agree you should be able to drive stock condition without boiling coolant dry... There's more to this than pump solenoid & viscosity!!

Replace both coolant circuit CAPS + OIL TSTAT + clean oil in whatever grade/brand you are comfortable with.
Make sure only specific coolant is used to preserve system integrity. I've had dealer use the wrong chem... don't be afraid to inspect what you expect.


What this confirms is your turbos cooling circuit is dealing with extreme heat that's not being removed.
🤞

 

Cali, you keep forgetting that the turbo coolant circuit is independent of the engine coolant circuit. The coolant that is overflowing does not enter the engine. The only connection it has to the engine is what little oil (relatively) is run through the turbo. If his turbo coolant reservoir is overflowing, then something else is going on.

 

JR, you know I am not forgetting the two coolant circuits are disjoined. Two distinct pressures, temperatures and extension tanks, yes.

What makes you say that?

As far as I know the open issue is the turbo circuit overflows while parked.

What else is going on here?

 

His oil temp is not excessive, even though a little high at 215°F, certainly not high enough to cause the low-temperature water circuit to overflow even if they were connected.

This is a bizarre problem. As the name implies, this is a low-temperature circuit (comparatively) and would only reach the temperature of the compressed/charged air coming out of the turbos since it is used only for the intercooler. The circuit has its own radiator sandwiched between the a/c condenser and the engine radiator. It also has its own electric coolant pump, so it should keep circulating the coolant throughout the low-temperature circuit. I don't know if the pump speed is variable or simply on/off. I can only think that maybe the radiator fan which draws ambient air through all four radiators is not operating at full capacity when stopped/parked and you have heat soak occurring when not moving.

(By the way, we have cross-pollenated with Old Man's other thread: https://mbworld.org/forums/w212-amg/...ething-up.html)

 

@OldManAndHisCar what engine do you have? The above diagram is for the M278 (and M276 bi-turbo).

 

Um...yes! One of each. This started with the AMG 5.5. Both engines have the solenoid taken out of the loop (and have dummy solenoids installed).

 

The original question:
-1- What cause the turbo circuit to overflow while parked?

then becomes:
-2- What causes a low temp circuit to overflow?


I associate low temp to low pressure...
It takes high heat to over boil a sealed circuit.
"low temp or high temp" are exclusive...

Overflow is a high temp condition...
...while parked I call this "extreme heatsoak".

I think this is associated with "stored heat"
and means ineffective heat removal.

​​​​​​Oil spray coolers is limited by oil pressure
everything after that is related to oil viscosity.

0/5W40 only sprays above 2700.RPM.
0/5W40 at 1200.RPM is dry lubed pistons regardless of MOD.

Be sure to use "MB Approved oil" for dry lubrication.


> BEWARE SP/SN:
-- I am not positive the cleaner API-SP chemistry is compatible with dry piston lubrication.
-- Approved SN chemistry uses heavy ZDDP to build up soft carbon, sort of like a graphite based lubricant.
-- A low viscosity API-SP with reduced Zinc: I dunno!

-- I am a proponent of matched viscosity for wet cooled clean pistons sealed rings near 1400.RPM.
Minimal losses make the engine control smooth and strong like a hammer from consistent fuel map!

> PARADOX:
-- low viscosity lubricants got coined as "gas-saving".
-- How can high blow-by losses deliver gas-savings ??

 

The low-temperature water circuit is the label that Mercedes uses to distinguish one circuit from the other. "Low-temperature" doesn't mean cold, it just means it is cooler than the primary engine coolant circuit. A derivative of Charles' Law relates pressure with temperature (or was that Hooke?). Regardless how the problem was originally stated, the pictures showed the expansion tank for the low-temperature circuit. Not sure, but if this was a picture of the expansion tank before it overflowed, it looks like it was overfilled. In which case, it would take very little heat and thermal expansion to overflow.

 

yes, user error is always a possibility.
It's happened before...

 

the tank is 100% overfilled

 

Courtesy of the oil geek himself Mr. Lake Jr....how cool is that
coolant temps are linked to oil temp, viscosity, aging and life span from field data collection.

Here is the new-brew...

Cleaner API-SP chemistry with lower ZDDP

It does nicely quiets engine heads. ✌️

 

Yep, we knew that. We expected the extra to seep out....this was the way it was after the Xentry bleed process (with the newest version of Xentry). I understand the process takes 20 some odd minutes, the computer controls the car engine RPM as well as making changes to the Heat/AC throughout the process.

 

these are different circuits... true ? @JettaRed


-- Any possible way "high heat" transfers into "low heat" circuit after engine stop??

-- We know 0/5W40 @ 1200.RPM is building up heat for extreme heat soak regardless of any MOD-0/1.

Something's causing this to materialize...
we'll know when correct solution is tested to work.

Whatever that may be.

 

No, drive it a bit...see if coolant in the garage happens again. Heavier oil next weekend...

 

Apparently there is a coolant flush function in XENTRY, but not where you would expect it. It's under test procedures. I suspect that's the engine coolant circuit and not the low-temperature circuit. I really do wonder, however, why it is not called out in the WIS. The WIS only uses the vacuum method.

 

FYI to set expectations clearly... even a more favorable 5/10W50 lubricant is not going to have enough pressure to spray at 1200.RPM.

You will still need to be in normal 1600.RPM range for active spray cooling.
Meaning enhanced spray-cooling still requires pressure - That is a combination of Viscosity + RPM.


Right now your tranny could be slugging into the very low gear that is hardly driveable. It probably starts up in 2nd gear too, right?

Use the steering paddle to train it to stay around 1600 -1800.Rpm shift points - That when engine can circulates heat out given matched viscosity.

You'll notice "extreme heat" missing after you return to garage! You won't believe it the first time.

+++ I am NOT advocating to skip from 0/5w40 to a better 10w50 oil directly.

it's just I have not tried feeding heavier oil to engine with stuck rings.
It may be totally beneficial or not... ?

To me "Experimental" does not mean crazy wreckless - It means a sort of calculated risk.
So I ramped up viscosity to match a spraying RPM
MOD-1;2;3;4 experimentally.

What I can guarantee is engine and especially tranny respond remarkably well to stable temps/viscosity given the conservative small steps I took. Heat is an enemy of predictable shifts.
You'll notice incremental improvements as you supply more favorable oiling conditions.

(MOD-1: same old heat!)

 

Cali, what pressure is required to start spraying pistons? I have at least 20 psi at idle (650 rpm), and 45 psi at 1500 rpm.

 

There is absolutely no need to change anything to enjoy stock experience. The "MB Approved" list of lubricants helps achieve that very well with "gas savings" included. What's not to like ? ​​​​

You forgot we've already looked at exactly that.
Numbers stand as stated :
"Nothing less & nothing more!"
​​​

You can try to measure accurately but
don't get lost again trusting MB salted Nos.

Personally I only want cooling but
We're here to learn a thing or two.
I'll help you seek accuracy to measure results.

​​​​​​> Cooling at normal driving speed requires higher viscosity, meaning:
-- Either drive with higher RPM
-- Or use higher oil viscosity
Options are yours to pick!


Normal city driveability dictates engine below 2500.RPM
My GDI fuel map has plenty torque on tap.
It transformed this chassis to act light and responsive: absolutely what I was missing with laggy throttle, slow heavy car.
Now it's nimble and cool.

When the pistons are sealed, the ECU is in the zone to hand out all the GDI gas you ask for - I can only imagine turbo charging a low blow-by sealed engine spray-cooled with 15w50.

That is solid performance + durability unlike dry lubed hot stock while it last.


Burning Approved gas-saving oil, guarantees standard fare:

• carbon accumulation
• stuck rings
• high blow-by
• contribution losses
• unbalanced cylinders
• random cylinders timings
• laggy fuel maps

Numbers are nice, yet:
THROTTLE SPEAKS!

 

You know JR: what's not obvious is that piston cooling is not effective as soon as squirters ball-on-spring opens up.

I agree that having 45Psi at 1500.RPM sounds well favorable at first considerations.

For comparisons :
GM idles oil at 40.Psi near 700.Rpm
MB 45 Psi at 1500.Rpm is not scary high


We should get good results because personally that's all I care for:

-- cooled engine bay without stock smelly extreme heatsoaks.

-- Not too demanding for top German brand, right?



What affects practical cooling results is the squirting being done only one side of piston and skinny squirter flow rate plus all the stuff I don't know...

It's not simple to plot clean cut results.

What's easy is to get lost with big oil marketing.
Lake Speed Jr. said clearly one time that "viscosity, viscosity and viscosity" is what matters the most.
- I respectfully concur!


Earlier I rationalized that "cooling pistons takes a firehose rather than a garden hose".
We can not change the hose size, so I increased pressure by way of viscosity.

When gradually going up viscosity range 5000.Mi at the time, you'll see that engine makes use of that and how it runs smoother and stronger as you feed it better lube.
All sorts of things improve: Hears, HPFP, rings seals, timings ...

Elsewhere I wrote that "oil begins to clean when it stops burning!" this is essential.
That's what we want and that is my marker for cooling efficacy.
Black oil points to failed cooling ie. extreme heat.

​​​​I dunno what temp or what pressure that is ?

I know it's an ENTIRE BALLPARK RANGE that can't be described by a simple figure.

The oil viscosity changes with temperature and mileage. The blow-by gases affect the heat oil receives.

Elsewhere I wrote about the "vicious cycle of burning oil thin" -
We want to stay above that tipping point especially with hot turbos heat!

When oil begins to thin out it keeps getting lower where rings accumulate burned carbon...

Right now we're in a 102F weather heat wave... Absolutely No intake burned oil or coolant heatsoak overboil leaking smell.

Right now I am on top of a threshold with 15w40... I just gave it a single 100mL honey booster @2222.Mi. to which it responded with more "start-no-crank!" after soaking 30mn or so.


I get perfectly consistent running and shifting regardless of high 100°F heat. Thanks to Bosch for that.

Hot/cold performance stays remarkably consistent: Heat removal is under control.



So 5/10/15W50 look like golden range based on actual use... regardless of what oil pressure does this.


> MEASURING VISCOSITY RANGE:
-- If you really into plotting numbers, find the viscosity that works then measure all the variables that describe it (viscosity, load, temp, rpm,...).

-- The other way around may not go anywhere once you find that engine drives with oil pump 60Psi bleed open 90% of the time. That may well be.
​​​​​​


> 1Mn Test:
If your oil dipstick is black before 3kMi
​​​​​​your pistons are not well cooled.


> MOVING HEAT IS SLOW:
Removing piston heat to the front radiator is extra slow.
It requires active pumping while driving.
Idling stopped moves no heat except A/C.

The overall balance of piston heat must be kept neutral at driving Rpm
else engine heat accumulates up <<< that's the formula!
We should remove more heat than we add into pistons.

Viscosity provides a grip on heat.


>> Extreme Corner:
you know i think with trends and limits rather than numbers
so I was wondering... then what happens when max everything is not enough to remove engine heat?

use an extreme lubricant to reduce frictions.
pump less power out of small volumes.

The max viscosity we can get is capped at 60Psi.
✌️

> MAXING OUT :
-- I have the hunch that I max out pump output near say 2 to 2500.Rpm wich MS! has shown us to be the working zone for pwr/torq.

-- That means that higher viscosity 20w50 may not add any extra benefits because engine pump is capped.

-- Turbo gear-pump does not have that limit thus could would benefit if it was not just a return suction return downstream of 60Psi feed - TBD.