Gents,

============ MY CAR IS RHD and M276.8 3.0 Turbo ==================== So hoses orientation on mine may not be the same as a LHD car

Ha ha ha......
I managed to remove the 2 coolant output pipes at the rear of Bank 2. This one goes to heater core and then comes back to engine mechanical coolant pump suction.
Hoses #1 and #2 also removed.



Because of hose #2, item 4 in blue plastic tray.....
I needed to do :
01. Wiper assy removed again.... Dugghh.
02. Wiper plastic cowling tray, removed again...Dugghhh + Duuggh
03. Water tray under wiper plastic cowling, removed again ...Duughh x 3

04. Vacuum pump needed to be removed, or else the 2 plastic pipes can not be removed.












Good thing the hose locking clip at hose #2 female bore at firewall to receive hose #1 male dicky, its locking U clip is oriented up 12 o.clock, so we can pull it to unlock using a long pick tool.


Hose #2 when installed as is, seen from engine bay to windshield ( wiper plastic cowling )



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The effort to un-plug hose #1 male dicky from hose #2 female bore is quite a force for a used hose and limited space.
Clearance is 5mm only before hose #1 male dicky assy will hit vacuum pump when we managed to remove the male dicky.


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At first I tried using string, as an assistance to pull out hose #1 male dicky, but it does not work.


Since my hose #1 is modified ( aka CUT mid way ) to install a pressure sensor, I can use big screwdriver as crow bar into 1/2 of the cut hose #1. Sort of.
Space is so tight between vacuum pump and hose #1, my fingers ( not hand ), does not have the power to pull out hose #1 male dicky.



Success with the long blade screwdriver as crow bar.



WILL CONTINUE.................

 

Funny thing is, when I eyed this task 2 years ago, I have always thought I needed to un-do more parts to access the vacuum pump and the plastic pipe #1, which is the pain in the azz.
Also the FACT is : hose #1 is needed to be removed first if I want access for vacuum pump small bolts. I have always imagined vacuum pump to be removed first, and then hose #1.

Being a RHD car, my battery is on the left. M276 3.0 Turbo starter positive wire has mid Vee bank bracket blocking my hand access to work from LEFT SIDE of vacuum pump ( eyes to engine bay, to windshield ).


To remove that steel bracket is a pain. I mean really a waste of time and energy as the access to its bolts is also tough and many more components to be removed first to be able
to remove that steel bracket.

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So I am very glad I DO NOT need to undo more components this time/task


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Prying out plastic pipe #1 is tough from engine block rear azz. I needed pry bar, again



As to not damage my vacuum pump cavity at engine cylinder head where the pry bar will surely needed that area as leverage, I used 1mm PU sheet as protection.











I use this type of pry bar, because its head angle is adjustable, hence it can go in straight, unlike traditional non adjustable head pry bar which need more room to be positioned.





WILL CONTINUE...............

 

This plastic pipes no 1 and no 2 can kill my engine if it breaks, hence it is my 10 year RENEW list, along with hose no 1 and no 2.
The hose no 1 and hose no 2 is also a problem, more so hose no 2 which if the car has heated windshield washer system, the plastic base housing ....the female bore of hose
no 2 and its small nipple for windshield washer heater is very thin and will crack, read here : https://mbworld.org/forums/e-class-w...lure-mode.html




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I am now at 10th year but only 40,000KM or approx 2,000 hours engine running, based on my proven average speed of only 20 - 21 KM/H.
The pipe no 1 and 2 still looks good, but it may crack when it decided to crack without sign of stress. Also who the hell can and will inspect this 2 pipes unless you will use a boroscope,
and still you cant inspect 360 degrees of it. The nipple which hold the o-ring to the engine block usually goes broken first anyway, and you can't see it.

M278 equivalent pipe #1 , but some has water solenoid. Newer ones the water solenoid is gone, no more. LOL.

Start at 14:58

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Can you imagine the labor cost in USA for this ?



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The hose #2 behind firewall.








3 locking clips.






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The heater core by-pass. The HVAC will be as cold ( better ) as a W204 or W212 with M271 EVO where there is heater valve. M276 3.0 or 3.5NA is a sad case of heat contamination.
Read here : https://mbworld.org/forums/e-class-w...ter-valve.html

Hose no 2 set up by factory. Hot coolant enter and exit heater core as per below :



ADD








Heater core bypass plan




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Testing heater core bypass plumbing.





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I do not want the hose to be stressed by me trying to close the 5CM gap by pulling the hose. So I will need a hose extension.



So I need to custom made something like this, but for the 18mm ID hose MB is using.




On order, this ALU pipe and I shall machine it down to make a hose to hose connection.




I want the custom hose to hose barb to be exact MB hose barb dimension.




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So I only need to cut hose no 2 at this approx point and make it longer by 5CM with the custom ALU hose extension.




Shall update end of this week when custom hose extension ALU hose barb machining done.............

 

Sizes for reference



All sizes in Millimeters
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Take note the 90 degrees elbow of hose #2 at firewall , the hose end is made a bit bigger than the other end into HVAC heater core. Even the hose barb at the plastic elbow is bigger in diameter.

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Hose Clam with LOCKER. So it can stay OPEN MAXIMUM without needing pliers assistance Be careful, this clamp is very strong if it pinch your fingers ...damn NO NO NO.
Use proper clamp pliers for this spring clamp. Knipex 85 51 250 AF it is so worth the money.



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Dumb-Azz MB radiator drain plug design. Can't do full bore opening like simple drain plug.
I have residue/debris/calcium/yada yada like those found in the heater core, but the drain hole is so small..... often it get clogged.

I dare not pull the drain plug OUT completely, I need to buy spare one first. It may break.
If the radiator's female port 2 locking tabs get broken...DUGGHHH, I must buy new radiator.
I really hate this stupid design.


This locking mechanism is similar to my aftercooler air temperature sensor.
South West is OPEN but need to pull up.
North West is LOCK.


This is so much easier and better design. Japanese car style. Full opening like a bolt or screw. No 90 degrees BULL-shiet and we get full bore opening,



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Aftercooler is much less calcium yada yada. I guess it never exceed 60C, so less reaction.


See the hardwater calcium trace at my thermostat, that was like that since 2019. What a crappy water MB Indonesia uses.



Look like the inside of a water heater using hard well water





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RADIATOR - Due to the hoses placement so high, both IN and OUT, flushing with pump is not as effective as heater core.

The calcium/debris can not be pushed that high. So drain plug is my best friend. And it is bad design

 

The guy on the E63 video removed the whole intake, intercooler etc. He could have removed the fake firewall instead, and access both the vacuum pump, and the faulty plastic hungry part.

 

I saw that video....
M278 is so much more crowded than my M276 3.0 Turbo. For me removing firewall is not effective and more troublesome in fact

 

Okey........
Extension pipe to make hose longer is ready and already installed.




The chafe protection is using 1mm PU sheet..

The cut-lengthened hose is new. Part of my 10th year program.


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I decided to keep heater core dry, instead of filled with coolant.
It is not say 100% dry, but only very few drops of water. I blew compressed air a lot into it.
So no need hose clamp, cable tie is good enough to hold the silicone caps.


Pressure test with new red coolant for radiator, engine block and the now by-passed heater core.

Zero pressure coolant level




Since I did not yet vacuum the radiator system, at mere 6.5 PSI, the coolant level is down, coolant goes into air spaces within the cooling system
This is 7 liters coolant. No more heater core, so probably I need 1 liter less at final filling.


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I am doing 15PSI test overnight, tonight.... so 12+ hours. So far the first 2 hours been good.

 

Congratulations Surya for this awesome tropical MOD...

No more engine heat pumped in the cabin to offset your cold evap coil - You nailed this clear out of the park !!


- A: lock stopper - B: open stopper tab

I wonder how can we remove the radiator 1/4-T. drain plug... without braking the little plastic stopper tabs??

Can we open the drain and pull it down by turning back a bit to stay clear from the lock tab?

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I am getting ready to deal with my radiator plug when I renew my 60kMi thermostat.
I have limited trust for T-stat overheated for 50kMi.
I am aiming for normal temp control.


accessoires easy tune-up

As of yesterday... I am test-driving my freshly soldered ESP with normal data timings on ECU/TCU CAN.

 

I have ordered the radiator plug, but its 30 days waiting. I too want too see how it is actually designed and how I can pull it out from the radiator safely.
The o-ring masked any mechanical resistance we feel when engaging threaded plug and with such unique shape one. That is why I am afraid.

How do you solder the ESP board ?
You need to open up the DC motor yes ?
Share please......

 

STATIONARY TEST

Now EVAP can hit 2 Celsius fast and easy ( need 1,400 RPM ).



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Idling





Older test of June 2021 and Feb 2023 , heater core as-is , not by-passed but in Feb 2023 I clipped the hose with a vice grip.




Previous to by-pass of heater core, the heater core is so hot, it robs coldness from the air delivered from EVAP to the middle VENT.
Back then VENT can only produce 7C or hotter, or the delta between EVAP and Mid Vent was 4C or more.
Now I can safely say that to get constant 5C at my mid vent is easy.


I don't like the way my RHD car hot heater hose is touching a bit of the EVAP input ( liquid line ) and output ( gas line ).
This is not good for efficiency. But no more room, as above all these hoses will be the wiper assy hiding there.




In my kind of humidity 85% or higher, HVAC power is lost much to humidity and being 30 - 33C in day time all year round is another sad affair.
Humidity is HVAC power sucker. If say 40C ambient but dry at 20% humidity like some part of USA, the HVAC work load is much easier than if it were in my city.

I will update when I get to test it on the road.

 

Today I went out, not too far. It was not mid day sun, but it was hot.
The HVAC is so awesome now, the air out of the vent is so cold, so dry....I am so happy.

With heater core by passed, the water pump now get reduced friction & restriction and at rear of engine azz Bank 2 where the plastic coolant pipe output is heading to heater core ( was ) , there located is my coolant pressure sensor.



8 PSI ( by-pass ) vs 25 PSI ( heater core flow friction & restriction ) at 6,000 RPM.


I don't have apple to apple test yet, but looking at my previous logs, I tried to find similar ones.
Right side scale in blue is only for speed in KM/H. All temperature data in Celsius, is left side scale in black.
The Heater Core ByPass log file is from engine cold start, the STOCK log file is engine already at 85C coolant temp. Thus I show data using minimum 80C temperature.
Also in STOCK log file, I ran a bit faster at the end of the log and higher RPM, as seen on 1st graph above.




Of course the differences between stock and HC by-pass is also a new thermostat now and a tiny bit cleaner radiator internal.

This short test look promising for the MUCH more relaxed coolant mechanical pump pressure at 4,000 - 6,500 RPM.
I shall update when I have more aggressive driving log file to heat up the coolant more.

 

This is are fantastic results
The coolant temperature test drive show heat is removed faster from half of the engine with HC-bypass. Now coolant pressure is reduced.
This brings a very significant difference in engine cooling in addition to A/C comfort.

In case your AAC module complaints about HC low temperature input or similar... we can solder a fixed resistor of appropriate value to fake the input.


Surya's advanced unplugs :

• ALT LIN... battery voltage
• AUX circuit... weight reduction
• Oil solenoid... piston cooling
• Heater core... A/C cooling!

 

I never seen N22/7 AC computer showing heater core temperature... I don't think so. Only EVAP temperature.
Maybe if the HVAC code 581 , a more upscale than my code 580, maybe it has more temperature sensors....for sure it has air quality sensor if I recalled correctly.