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!

 

[samnt650]

Finally heard back from IG HQ >> they want to replace the motor. Working on finding out how they came to this conclusion...

 

[Lord Ripon USA]

Finally heard back from IG HQ >> they want to replace the motor. Working on finding out how they came to this conclusion...

Probably coolant test showing overheating.
Or some other evidence of overheating.
Perhaps the EMS records temp, and the data showed extended high temp, verified with data from other sensors.

Rather than leave you with a time bomb, it’s probably cheaper and easier to swap the lump out before it blows.

 

[anand]

Probably coolant test showing overheating.
Or some other evidence of overheating.
Perhaps the EMS records temp, and the data showed extended high temp, verified with data from other sensors.

The vehicle was driven by the OP whilst well over operating temp (see his first post)... and of course, for all faults there will be freeze frame data showing all the rest of the pertinent parameters

 

[LeeroyJ]

That’s not normal at all unless perhaps you were towing in the mountains with a big load. Perhaps the valve is defective - the one that cuts coolant flow when vehicle is first warming up. I’m surprised you are seeing this with the b58.

Even when I tow my 6500lb trailer up steep mountain passes, it rarely gets past the 194 mark, and when it does, its just a little above that and comes down remarkably quickly once the incline tapers off. That includes some +100F degree days on a 3000 mile trip I did recently. So I agree with you that the OP's temps are not normal.

 

[Lord Ripon USA]

The vehicle was driven by the OP whilst well over operating temp (see his first post)... and of course, for all faults there will be freeze frame data showing all the rest of the pertinent parameters

OP provided a screen shot
No analog evidence of anything hot
Could just as easily have been a faulty sensor
Or just another ems gremlin

I’m glad they are stepping up
That unit should have been throwing codes at the posted temp if real.

Perhaps OP posted more of his experience somewhere else.

 

[j3t3r]

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...

Well damn, I guess I have the second case now. Very similar experience to you. Been off roading a handful of times, no overheating issues. Always try to wash all the mud off as well as I can afterwards. Then driving back home at highway speeds engine starts overheating. Light goes away the second I slow down or get off the gas. Turning the cabin heat on full blast seems to somewhat mitigate the issue. I contacted my dealer about it have not heard back from them.

 

[AWo]

Driven through mud? Cleaned all coolers, also in the bumper?

AWo

 

[j3t3r]

Yes all that is clean. But does someone know which is the main coolant reservoir and which is the auxiliary ? And if both reservoirs take the same color coolant?

Looks like blue cap reservoir is on passenger side and drivers side is black cap.

Driven through mud? Cleaned all coolers, also in the bumper?

AWo

that

 

[j3t3r]

Yes all that is clean. But does someone know which is the main coolant reservoir and which is the auxiliary ? And if both reservoirs take the same color coolant?

Looks like blue cap reservoir is on passenger side and drivers side is black cap.

that

 

[255/85]

Yes all that is clean. But does someone know which is the main coolant reservoir and which is the auxiliary ? And if both reservoirs take the same color coolant?

Looks like blue cap reservoir is on passenger side and drivers side is black cap.

that

I thought one is the high pressure circuit and the other the low pressure. Previous versions of the engine had two separate systems. One for the engine and associated and one for the intercooler. That may have changed with the eSCV vs. an actual thermostat.

https://bmwtechinfo.bmwgroup.com/tech_training_manual/ST1853%20B58TU%20Engine.pdf

 

[samnt650]

This is the response I received from IG, when asked what could be the root cause of the overheating... at least my truck is back