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1st install location is not good at all.
It is between the coolant expansion tank to radiator.
So I can't truly monitor engine coolant pressure output by coolant pump and what pressure is the engine block getting.
1st install location
Stationary test
ON THE ROAD TEST
======================
NEW INSTALL LOCATION.
This is to serve 2 purposes.
A - Get better/accurate coolant pressure reading.
Good for me that the hose diameter ID of the one to HVAC heater core is the same as the 1st location. So the hose sensor adapter I can use same size, which is 18mm main pipe OD and 20mm the hose barb OD.
I discovered that this hose actually touches the soundproof carpet/fleece-foam of the false firewall (heatshield). See below.
So when air filter box is installed, this hose which uses o-ring connection to the engine block can spin quite freely and it ended up touching a tiny bit on heatshield. No wonder it has sort of extra mesh-fabric protection on the hose
So far no harm to the mesh-fabric, but my engine mount is super pristine as I replace them every 20,000 - 25,000 KM. I am on my 2nd replacement now.
1st one at 10K KM, 5 years age and recently Feb 2021 at 28,800KM. Now car is 36,000KM ish.
If engine mount is shaky shaky, this hose can tear from rubbing , eventually rubbing the aluminum plate of the heat shield.
Measuring to cut a bit of the hose length.
The aftermath of MB Indonesia bad water source at its assembling plant and low coolant concentration too !!!.
I never replaced this hose yet, so it is still historical evidence.
The aftermath : https://mbworld.org/forums/e-class-w...i-am-sure.html
I am stll using this 8 years old hose for now because still in testing phase.
It will be replaced by 2024. See the shi-et I get. I bet my radiator fine capillary also get this shi-et
This hose cord is kevlar. It is yellow Kevlar color.
Spare hose on hand already.
The o-ring has shrunk a tiny bit at the connector towards engine side, the one which can spin.
The plastic pipe end from engine block rear azz. You can see the o-ring chaffe marks on it. In 2024, this will also be replaced.
I have a 10 year refresh plan in the works.
Improve chaffing protection for the heatshield and the hose.
Heastshield get 1 layer of aluminum foil and 4mm thick HVAC insulating foam.
Hose get 1 layer of HVAC insulating foam
See, with airbox installed, the hose will surely be pushed to kiss the heatshield. M276 3.0 E400 W212 owner do pay attention this.
All I need to do is add the extension wire harness from 1st install location. Good thing I got spare of this extension wire from Banks Power
Routing the new wire harness
For the sharp eyes
Below's black 6mm wire with green electrical tape end, that is added ground cable for BOTH cylinder heads. Taken from alternator negative bus bar ( body ).
That is a tin plated high grade copper and is a 120C continuos rate cable for solar panel application. This brings up 0.3V improvemen to my ECU voltage.
ECU gets its negative from cylinder head at Bank 2. Cylinder head is a distant away from main negative cable feed to engine which is at starter motor.
Gasket, dirt on the bolts and yada yada from starter to cylinder head = resistance.
I have added 50mm square millimeters welding cable to alternator negative BUS BAR which I made, it is direct from battery negative post at suspension top mount.
This car get lots of DC negative path improvement.
No on road test yet. Only stationary.
I took just a short bit out of the entire 30ish minutes test.
Its the section where I raised to 4,200 RPM ( soft limiter ) and get 105C coolant temp and let it idle to cool down and then play with engine rev a bit.
Now I can see the full glory of the coolant pump pressure and sometimes , depending on how NOT too hot the coolant is, the thermostat when opens up, I can see pressure drop at the sensor.
I am wondering what 6,000RPM WOT coolant pressure will be like
Let me do some test drive first and chase the B target of this project.
B is to reduce as much as possible coolant flow to HVAC heater while heater core MUST still useable.
Today stationary test the HVAC heater output is still crazy hot aka wasting energy for me.
I been doing flow opening calculation of this hose and now with sensor adapter and soon if I do install restrictor tube/orifice.
Technically I am now already creating a restriction to the flow of the coolant because of the hose style sensor adapter.
As to what ratio in liters per minute reduction a shrinking hose ID % will be, i don't know, it is not that easy to calculate.
I already ordered a Teflon ( PTFE ) rod of 20mm OD. So I can machine it as a restrictor.
The hose end towards the false firewall ( heatshield) is a flat unique shape at the elbow.
So I can simply place this restrictor inside the hose, after the sensor adaptor and it won't be swallowed by HVAC heater core
Once all further test completed and results are in, I might want to cool down the turbocharger spent/return coolant like the M278.
Being like M278, but using electric water pump ( like aftercooler ) and a baby sized motorcycle radiator.
At the bumper, the lower RIGHT side air grille is there useless. LEFT grille is where my ambient temp sensor is at.
There are 2 candidate of radiators from Honda CBR150 ( 18HP ) and CBR250 ( 38HP). I have to hold them in my hand to measure their size, but it is quite small.
The electric cooling fan also original from Honda.
If I can lower by a mere 30C on the turbo coolant return , perhaps overall engine cooling can get some decent assistance, maybe 3 to 4C , maybe.
The lower air grille is approx 30cm wide and 15cm tall.
The electric fan and the electric water pump will be thermostat operated say at 80C. I can use bimetal thermo switch operating a relay.
When doing WOT to 6,200 rpm and car is moving , the coolant pressure is much higher than previous rev limited 4,200RPM stationary test or slow moving test.
Wow, near 25 PSI.
FAST DRIVE, with lots of WOT. New Sensor Location.
Please note that this new sensor location ( 2nd try) is the hottest , end of circuit and highest pressure of all .....most of the time and more so when thermostat is not 100% fully opens.
MB coolant temp sensor is very close to this new sensor location too.
The expansion tank itself where its hose was the 1st try pressure sensor location is the coolest zone because its coolant is after being cooled by the radiator and is nearest to coolant circulation pump
suction hose, so by pressure it is also the "mildest", hence never ever I seen even 3+ PSI at WOT, as shown below :
Below : 1st try pressure sensor location at hose to expansion tank. FAST DRIVE with lots of WOT
Let me think...
That means your engine temperature is reaching the 25 PSI Max cap venting pressure, right?
That sucks 😳
Improving cooling:
May be it's time to test fancy "wetting agents" used in high power engines. This may help improve cooling or old-fashioned snake oil scam??
Well yes near 25 PSI ... BUT not at the Expansion Tank.
Expansion tank unless my engine overheats, seems to be experiencing no higher than 3 PSI.
You have to divide the cooling system into many segments both temperature wise and pressure wise and which zone get coolant pump HEAD pressure.
As I said, pressure comes from 2 sources, coolant pump head and expansion of hot coolant.
Expansion tank only see pressure rise from expansion of hot coolant and not from coolant pump HEAD pressure
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by CaliBenzDriver
Let me think...
That means your engine temperature is reaching the 25 PSI Max cap venting pressure, right?
That sucks 😳
Improving cooling:
May be it's time to test fancy "wetting agents" used in high power engines. This may help improve cooling or old-fashioned snake oil scam??
Maybe not! I used this stuff in my 2000 VW Jetta with G12 coolant back in the day. G12 and Water Wetter did not like each other. Immediately, I got a brown sediment form and had to flush my cooling system. Not sure how it would react with Mercedes GXX coolants.
10-15-2022, 09:14 AM
