A Summertime F.Y.I.
Here in Las Vegas yesterday, while driving home on the freeway in 210°F temperature, I averaged 212°F on my UltraGauge. At idle, after exiting the freeway and waiting for the stoplight, it crawled to 221°F. Once home, I turned the a/c off and let it idle in the driveway for 5 minute before shutting it off - it came back down to 210°F.
This all got me wondering what the maximum coolant temperature of the Bosch 4.0 is before damage occurs. Well, according to the Workshop Manual, I found the following below, on page 88-19:
"High engine coolant temperature warning lamp
The high engine coolant temperature warning lamp within the instrument pack utilises a red LED and a clear legend.
The ECM illuminates the LED when it detects the engine coolant has exceeded a temperature of 121 °C (250 °F) and
switches it off when the coolant temperature drops below 118 °C (244 °F). The ECM also illuminates the high engine
coolant temperature warning lamp when it detects the PWM duty cycle to the temperature gauge is out of range. If it
is greater than 94% duty cycle when the engine is hot, or less than 8% duty cycle when the engine is cold, the engine
coolant temperature gauge pointer will indicate cold, thus alerting the driver with an additional visible warning.
When the ignition is switched on, the ECM illuminates the LED to provide a self-check, providing there is no fault it
will remain illuminated for 3 seconds or until the ignition is switched off.
The response of the engine high temperature warning lamp varies according to engine type and market, there are
three conditions:
HOWEVER, the above is not to suggest running that engine anywhere near 244°F is okay. Buy an aftermarket digital temperature gauge and keep an eye on it. Best to purchase one with a programable alarm. I have mine set at 212°F.
Lastly, if your engine overheats, don't shut the engine off unless you have sprung a leak and lost all your coolant. Why? Continuing to pump coolant through the block's water jacket will quickly and efficiently reduce the internal temperature, provided there's no load on the engine; take the truck out of gear, turn off the a/c and point the nose into the wind. By turning your engine off, the coolant temperature will quickly rise promoting further damage.
Enjoy the summer heat!
Here in Las Vegas yesterday, while driving home on the freeway in 210°F temperature, I averaged 212°F on my UltraGauge. At idle, after exiting the freeway and waiting for the stoplight, it crawled to 221°F. Once home, I turned the a/c off and let it idle in the driveway for 5 minute before shutting it off - it came back down to 210°F.
This all got me wondering what the maximum coolant temperature of the Bosch 4.0 is before damage occurs. Well, according to the Workshop Manual, I found the following below, on page 88-19:
"High engine coolant temperature warning lamp
The high engine coolant temperature warning lamp within the instrument pack utilises a red LED and a clear legend.
The ECM illuminates the LED when it detects the engine coolant has exceeded a temperature of 121 °C (250 °F) and
switches it off when the coolant temperature drops below 118 °C (244 °F). The ECM also illuminates the high engine
coolant temperature warning lamp when it detects the PWM duty cycle to the temperature gauge is out of range. If it
is greater than 94% duty cycle when the engine is hot, or less than 8% duty cycle when the engine is cold, the engine
coolant temperature gauge pointer will indicate cold, thus alerting the driver with an additional visible warning.
When the ignition is switched on, the ECM illuminates the LED to provide a self-check, providing there is no fault it
will remain illuminated for 3 seconds or until the ignition is switched off.
The response of the engine high temperature warning lamp varies according to engine type and market, there are
three conditions:
HOWEVER, the above is not to suggest running that engine anywhere near 244°F is okay. Buy an aftermarket digital temperature gauge and keep an eye on it. Best to purchase one with a programable alarm. I have mine set at 212°F.
Lastly, if your engine overheats, don't shut the engine off unless you have sprung a leak and lost all your coolant. Why? Continuing to pump coolant through the block's water jacket will quickly and efficiently reduce the internal temperature, provided there's no load on the engine; take the truck out of gear, turn off the a/c and point the nose into the wind. By turning your engine off, the coolant temperature will quickly rise promoting further damage.
Enjoy the summer heat!
