Nhân ngày nắng nóng, A lại nhớ chú laze_a1 nên lang thang các diễn đàn của các bạn Tây về vụ nhiệt độ nước
Có một chú viết rất chi tiết v/v ''nước nóng và quạt cho Engine 104'' của S320
Aux fans should not run all the time
Various actions of your cooling system (including the aux fans) under a variety of conditions are listed below:
I believe you have an 87 degree thermostat, and that is the temp that your t-stat starts to open. I'm sure your car should be running between 87 and 92 degrees most of the time, and will probably run about 100 degrees at an idle in hot weather with the AC on. Here is what the MB CD says about the cooling system and temperatures on M104 engines:
Thermostat will start opening at 85 to 89
Thermostat will fully open at 102
Viscous fan clutch will cut-in at 96 to 104
Viscous fan safety cut-off will ocurr at engine rpm 4500
The same will ocurr at fan rpm 3250
Electronic fan (1st stage) will cut in at 16 bars of refrigerant pressure)
Electronic fan (1st stage) will cut out at 11 bars
Electronic fan (2nd stage) will cut-in at 107
Electronic fan (2nd stage) will cut-out at 100
A/C will go into 50%on, 50%off cycle (20 seconds interval) at coolant temp 121 to 123
A/C will go into emergency shut-off mode at 126 to 128
Pressure cap will open at bar 1.3 to 1.5
Coolant temp max is 130
Remember that water boils at 100 degrees celsius, but with a 50 / 50 mixture of water to coolant, your boiling point is raised to 120 degrees, and the car isn't considered to be overheating until the temp exceeds 130 degrees.
MB designed these cars to run hot, and 100 degrees is not even considered close to being hot.
Now, many of us on this forum (including me) doubt the wisdom of the brilliant German engineers for these cars, and carry out modifications to prevent the car from going much over 100 degrees.
I have installed the "cool harness" that JimF sells, and it causes the high speed auxillary fan to engage at 100 degrees, and runs until the temp reaches 82 degrees.