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I don't know about the M276 but on the M272, the thermostats used to go bad all the time. My guess is that your thermostat is stuck open so it doesn't run as efficiently. A scanner might be able to tell you if you have a pending code or actually read the temperature.
I don't know about the M276 but on the M272, the thermostats used to go bad all the time. My guess is that your thermostat is stuck open so it doesn't run as efficiently. A scanner might be able to tell you if you have a pending code or actually read the temperature.
i’ll do a scan and see what up just in case, but alls back to normal.
Originally Posted by juanmor40
seen it on mine as well, driving open highway after midnight 95+ MPH . However, once at the traffic light after the ramp it goes up fast
this is more reassuring since mine has also gone back to normal, i want to say it was because we had similar conditions (open road and cool air)
cmon have to check both at all times, that being said, i’m paranoid about my car so i’m always checking everything all the time 😂
I'm not paranoid about my car. When it's snowing, I am paranoid about the idiot drivers around me who haven't a clue how to drive in the snow... so my vision is through the windscreen, not on my instruments. I'll just add that when snowing, I never exceed any speed limit, so no need to look at the speedo, either
Dash gauge is dummy gouge, so for it to show below 80C, the temperature had to drop down to 70C
I drive my diesels with monitoring scanners and having long downgrades on desert, the engines who normally operate at 85C will cool down to 78C.
The dummy gauge stays firmly at 85 however.
The above might be indication of thermostat closing too late, but without real gauge, we can guess endlessly .
Dash gauge is dummy gouge, so for it to show below 80C, the temperature had to drop down to 70C
I drive my diesels with monitoring scanners and having long downgrades on desert, the engines who normally operate at 85C will cool down to 78C.
The dummy gauge stays firmly at 85 however.
The above might be indication of thermostat closing too late, but without real gauge, we can guess endlessly .
also noted. i do suspect it may be the thermostat. i’m buying one and i’m going to put it in myself as i’ve actually seen the needle drop to 50C (it was 22F/-5C) and that spooked me. we are expecting -2F/-18 and i don’t want to find out what the gauge drops to then 😵💫
It is easy to check if your thermostat is "leaking" or semi-open aka un-able to close maximum when engine still cold or maybe open up too soon on its own, or ECM command.
Mechanically the thermostat is suppose to open ( wax melting ) at approx 90C and upwards and this is without the heater assist and can be sooner if for some reason the heater assist in progress.
U will still need OBD2 based gauge as a true coolant temperature reader and if you have a thermal gun it will be nice, or you can use your hand as temperature sensor
to feel the hose at the thermostat housing output side, the one to the radiator.
FIRST UN-PLUG the connector for heater at thermostat R48. It is a 2 pin connector.
The heater connector you then connect to a test light or any 12V bulbs of no higher than 5 watts, T10 bulbs from your trunk side light is 5 watts .
This is to visually see, if your heater get any signal too early before 80C.
We need to exclude false triggering electrical wise and verify mechanical separately.
Mechanical
If say OBD2 gauge read 70C already, compare it to your Instrument Cluster one ( need a friend to assist ) , IF you by 70C to 80C OBD2 value can feel the the hose for heat, the thermostat is kinda "leaking" or opening too soon.
Here is at what temperature the heater is used to assist earlier opening of the mechanical thermostat and 95C is when mechanically the thermostat will open itself maximum https://mbworld.org/forums/e-class-w...mperature.html
Just an update all, it was my thermostat, i changed it out and my temp is back at the 90-95C range. thanks for all of your input and brainstorming with me 🫡
Originally Posted by cetialpha5
I don't know about the M276 but on the M272, the thermostats used to go bad all the time. My guess is that your thermostat is stuck open so it doesn't run as efficiently. A scanner might be able to tell you if you have a pending code or actually read the temperature.
Originally Posted by kajtek1
Dash gauge is dummy gouge, so for it to show below 80C, the temperature had to drop down to 70C
I drive my diesels with monitoring scanners and having long downgrades on desert, the engines who normally operate at 85C will cool down to 78C.
The dummy gauge stays firmly at 85 however.
The above might be indication of thermostat closing too late, but without real gauge, we can guess endlessly .
Originally Posted by S-Prihadi
Here is at what temperature the heater is used to assist earlier opening of the mechanical thermostat and 95C is when mechanically the thermostat will open itself maximum https://mbworld.org/forums/e-class-w...mperature.html
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. However, once at the traffic light after the ramp it goes up fast
