Petrol/Gas B58 Overheat at Highway (Motorway) Speed

[Mountain4x4]

Wade mode left on somehow? But that would overheat more at slow speeds. This cooling system is extremely robust. I have not been able to move the needle at all. Maybe one of those random modern vehicle air bubbles. Surely BMW is not using plastic thermostats like the geniuses at Ram did on the new Hurricane.

 

[samnt650]

Update from Ineos UK HQ - this is the first case of engine of over heating at speed. They are literally doing all kind of test with my truck. Can only hope this wasn't cause by something simple like "loose bolt" LOL...

 

[Lord Ripon USA]

This is a timely reply. Today, evidently a wire to the temperature control module on the side of my trucks engine broke. The part that matters is,

A symptom was the truck thinking it was overheating, shutting off the air conditioning to lower the strain on the engine, it went into limp mode, and the dual radiator fans ran wide-open.
I was convinced I was overheating, but was not.
The thing is, the truck never actually got hot. Just the computer thought it did because the wire had a broken connection.

 

[Tazzieman]

The thing is, the truck never actually got hot. Just the computer thought it did because the wire had a broken connection.

I presume the gauge was saying normal?

 

[Lord Ripon USA]

No, gauge was dead. Below 160 Fahrenheit. Unresponsive.
Which is a common symptom of low coolant. Upon cooling, cool and reservoir needed about 1 qt of coolant. Maybe less. System hold 3 gallons when full.
Added coolant, ran engine at 2000rpm, turned heater on full blast to move any air out, still no gauge reading, and fans running wild. Cab hotAF. (Summer here yet)
And the A/C turned off message still reporting.
OBD code reader says temperature control module fault.

So, I pulled off the shrouds, went and got a thermostat and TCM, and set about the changes.

Turns out a mouse had chewed the wire that connects to the TCM.

The on board computer interprets an open circuit there with high engine temp, and then works to protect the engine.

Damnable field mice. Harummph!

I relayed this story because perhaps the engine management on the Grenadier is similar in function and logic.

Which is that a fault in that sensor lead tells the computer the vehicle is overheating massively.

 

[Tazzieman]

Turns out a mouse had chewed the wire that connects to the TCM.

All my cars live outside; I live in the bush In Australia. Never ever had a problem with rodents or other critters.
Maybe the snakes scare them away?

 

[Mountain4x4]

Freaking rodents are bad news.......

 

[Tinerfeño]

Which is that a fault in that sensor lead tells the computer the vehicle is overheating massively.

I don't consider this bad idea. At least now when it is known.
In workshop I always use external temperature meter to verify overheating, On roadside you can get feeling by holding top hose in your hand: If it is very hot and there is more pressure than normally the engine is overheating.
I once blew head gasket on my Discovery 200Tdi when I was pulling a trailer back from autumn weekend trip in dark, with blown backlight bulb and radiator blocked with moss ...

 

[Tazzieman]

In workshop I always use external temperature meter to verify overheating,

I carry an IR thermometer in the vehicle. Many potential uses!