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2002 Land Rover Discovery 2
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Discussion Starter · #1 · (Edited)
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!
 

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My '99 DII. I have a gauge which plugs into the OBD2. When running the AC, it will always try to get too hot. When the gauge reaches 99 or 100C, I just turn off the AC. Even sitting in traffic it immediately cools down. The tip about not turning the engine off when too hot is right on spot. So far I have had to replace the head gaskets on two of my three DIIs but that was before I got the gauge.
 

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Here in Las Vegas yesterday, while driving home on the freeway in 110°F temperature, I averaged 112°F on my UltraGauge. At idle, after exiting the freeway and waiting for the stoplight, it crawled to 121°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 110°F.
Are you sure that the bolded figures are not starting with 2 ? as about how the cooling system was conceived see the attachment, LR considered that things are getting too hot at 212F hence the electric fan should kick in then

Try to stop the viscous fan with a rolled up newspaper when the radiator is hot, if you can your problem is that the fan doesnt lock well so not enough air flow for cooling so you need a new viscous unit, they used to get "tired"
 

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Land Rover has the fan set to come on at 212, so my assumption is that 212 is what they consider to be too hot. Personally, I’d be worried if mine got that hot because of head gasket/dropped sleeve concerns. I start taking an effort to cool things off around 208.
 

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A Summertime F.Y.I.

Here in Las Vegas yesterday, while driving home on the freeway in 110°F temperature, I averaged 112°F on my UltraGauge. At idle, after exiting the freeway and waiting for the stoplight, it crawled to 121°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 110°F.
Yeah, uh, I'm not buying that your truck averaged 112°F. Did you mean to type 212°F?
 

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Discussion Starter · #7 ·
Land Rover has the fan set to come on at 212, so my assumption is that 212 is what they consider to be too hot. Personally, I’d be worried if mine got that hot because of head gasket/dropped sleeve concerns. I start taking an effort to cool things off around 208.
[/QU
Yes, he certainly meant Centigrade; matches my DII. Just a typo.
Yes, I meant in the 200s. I just corrected that.

Thx.
 

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Discussion Starter · #8 ·
Are you sure that the bolded figures are not starting with 2 ? as about how the cooling system was conceived see the attachment, LR considered that things are getting too hot at 212F hence the electric fan should kick in then

Try to stop the viscous fan with a rolled up newspaper when the radiator is hot, if you can your problem is that the fan doesnt lock well so not enough air flow for cooling so you need a new viscous unit, they used to get "tired"
Yes, and that's exactly my point. The fan comes on a 212°F, but the warning light comes on at 250°F. That way too much of a spread. At 212°F I want to start watching the temp, well before it hits 220°F, or above. When the light comes on at 250°F it's too late. Stupid design.
 
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Discussion Starter · #9 ·
Are you sure that the bolded figures are not starting with 2 ? as about how the cooling system was conceived see the attachment, LR considered that things are getting too hot at 212F hence the electric fan should kick in then

Try to stop the viscous fan with a rolled up newspaper when the radiator is hot, if you can your problem is that the fan doesnt lock well so not enough air flow for cooling so you need a new viscous unit, they used to get "tired"

My viscous fan works properly. I replaced the entire cooling system two years back.

I also have to consider my Warn winch and Hella 2000s (3 total) that may be blocking the air-flow. Then again, the motor is getting old and my need a new head gasket.
 

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Are you sure that the bolded figures are not starting with 2 ? as about how the cooling system was conceived see the attachment, LR considered that things are getting too hot at 212F hence the electric fan should kick in then

Try to stop the viscous fan with a rolled up newspaper when the radiator is hot, if you can your problem is that the fan doesnt lock well so not enough air flow for cooling so you need a new viscous unit, they used to get "tired"
Your in Romania? Are you near Timisoara ?
 

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I curious has anyone added an oil cooler to your d2? I had a pro built 440 at over 500 hp and added one for hot summer days. It dropped the temperature 17 to 22 degrees and the oil always looked better. Im thinking of adding one to my d2. Oh, with a built in fan.
 

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I just put a new engine in with a new cooling system, and it runs at around 200 to 210. I'm in Arizona. Don't forget there is a benefit to running around 212, you boil off water in your oil, and that prevents sludge build up. I think it runs that hot intentionally for that reason.
 

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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!
Check the thermostat, the viscous fan, and the radiator. Probably the radiator is becoming plugged or one of the other things I mentioned needs to be replaced.
 
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