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Anyone ever open up M276 thermostat housing internal ?
Hi All,
I read newer 3.5 liter M276 non turbo also uses the same as thermostat housing as M276 3 Liter Bi-Turbo one.
Have anyone ever removed the actual thermostat, or the 3 screws I marked red ?
I want to open the 3 screws , but I am hoping someone who has done so, could tell me if the sealing is just simple o-ring , or something else which I better not open up.
Why I am asking is, I do not see thermostat only part number, it is this whole thermostat housing only available and that made think could it be its not meant to be opened up ? https://www.autohausaz.com/pn/MB-2762000315
The brand is WAHLER, just like what BMW often uses.
I found this drawing on my cheapo ebay bought EPC/WIS disk set ... LOL
It is under "SSL" section.
This quest brought me new info after extensive googling, that this thermostat is a MAP ( engine ECU ) controlled one.
It has an electrical heater element inside the thermostat. Something like below :
I never investigate it farther, but some new cars have electrovalves instead of thermostats.
ECU controls opening, just like in heating system valves of last 20 years.
I had it on my 2008 Bluetec and did not like it. When cluster temp gauge seems to be dummy gauge, the climatronic display, what I understand is what ECU sees was showing 85C going uphill, or 74C going downhill.
Would expect better from a computer.
The video shows water pump pumping backwards.
oh oh , totally electric valves for engine thermostat sounds risky. mechanical thermostat at least they don't usually fail 100% failed to open, lesser opening usually and if we are alert we can detect it.
I think your gauge is kinda smoothed out one ? I know some marine fuel gauge does that smoothing, otherwise it will swing like mad when boat pounding into waves.
Most of the older thermostat failures I had was stuck open. Usually a leg breaks and will not hold the piston close.
"Dummy gauges" are know for years, where manufacturers got tired by costumers complain about temperature fluctuating between 80 and 90C, or oil pressure between 1 and 4 bars.
That is why programs keeps the needle steady until something major happen. I liked MB gauges for years as being accurate gauges, but lately MB went with the trend.
That brings a danger as I experienced on my Ford truck. Going uphill the needle went from "normal" to "overheat" in 3 seconds. By the time I was able to pull over, the coolant all boiled out.
Anyway, maybe I was wrong about electrovalve and it is what you have found.
My usual experience on common mechanical thermostat is not to the extend of being broken and stay open, but worn out center shaft causing extra friction as such the valves wont come down and open
100% as its should.
Today's car simplified too many gauges. My 2011 Ford Fiesta does not have COOLANT TEMP gauge, insane !!! Only overheat warning, which I fortunately never triggered... LOL.
I agree with you, I rather have a lively temperature gauge to detect a temperature increase trend even how minor.
Back in the 90s my friend had a yacht with 2 x 10 cylinder 820HP MAN @2,300 RPM. This is pure mechanical engine, also no CAN bus , simply analog.
Normal operating temperature is 85C, it has stand alone overheat sensor probe which s 97C if I remember correctly.
97C is way too hot and it will warp the cylinders if ever it hits 97C.
So there was this company selling adjustable alarm module, a simple design. It has a feature where I can simulate temperature increase on the temp gauge and set trigger point anywhere I want.
So I set a 90C as early alarm or on-the-way-to overheat concept and keep the original 97C final overheat sensor.
I added a lot of extra monitoring system on these engines.
Example, engine oil pressure, I also added the early alarm set at 65% normal oil pressure. This engine low oil pressure alarm set point is too low, I think at 20%.
Some oil pressure increase is only at gear engagement and higher RPM, example the marine transmission, at cruise RPM of anything above 1,200RPM ( gear engaged ) it is 25 BAR / 367 psi being normal.
So I got to install an RPM based module where some of the added early alarm function will only be activated after certain RPM only, otherwise it will beep-beep all the time at engine idle neutral gear or lower RPM... LOL.
In the later years like 2005 ish, the electronic version of the same engine get CAN bus and whatnot and they have variable engine oil alarm based on RPM.
I think the overheat alarm also get smarter, it has this temperature rise vs time profile, which can detect a unexpected super fast temperature rise over very short duration which can potentially
be an over-heat condition in progress, before actual final overheat value reached.
So much for the good old days where we can monitor things the way we want them without needing scan tool ....
Yes I read about those bluetooth OBD2. Drooling indeed... he he he he
Thinking to get one, but I really dislike/fear putting extra stuff /tablet on my dashboard which ( touch wood) can become projectile during an accident.
When TorquePro works well with $5 Bluetooth plugs, I don't think boat will have OBD
Side issue is that I found those plugs showing false data. ... like 1000 psi in my exhaust. I did my share of scuba and know what 1000 psi can do to a metal, so I am 100% sure this is not real.
But anyway, fun to talk about all those new technological gadgets. Who would guess new thermostats come with heater.
Someone on this forum, I can't remember who, have replaced that complete thermostat housing assy because the thermostat it was mild stuck OPEN, so engine too cold.
Sold as assy that thermostat+heater combo