Engine Temperature

[Ectopic]

My 2021 1250GS has a BMW Nav5 and on one of the screens you can pull up live data from the bike. One of those is coolant temperature.

I noticed today when riding along (about 20C ambient temperature) the coolant temperature is constantly changing. It will drop to high 70s, then slowly increase to low 90s in the space of maybe 2 minutes, then drop quickly (in 20 seconds or so) back down to high 70's. Repeat indefinitely.

I don't think the fan is coming on. That kicks in in the high 90s normally, and when stationary it brings the temp down by maybe 5 degrees in a couple of minutes even in 35+ air temperatures.

Is this cycling from high 70s to low 90s normal? I've had the bike since new and there's every possibility that it has always done this. I've never really looked before as I didn't have the temperature showing on that particular screen until recently. And if it didn't have the temperature gauge I would never have known, so I'm not overly concerned about it.

If anyone fancies a little task while out riding, it would be interesting to know if they all do this.

 

[Santa-2512]

Pretty sure thats normal,

My LC used to do the same, but i dint really observe the temps , but 90c sounds about right

old cars have used to have a fan running all the time, so there cooling from the off - sapping 10% or so of engine power keeping the fan spinning - later iterations included viscous fans to decouple the fan at low temps

Modern cars (and liquid cooled bikes) have a temperature controlled and decoupled fan which only runs as requied less energy to run, and more efficient

The only reason you are seeing the cycling is you have access to the live temps

If you had an old Hexezcan, you could use it as a data logger, and monitor up to 32 channels of data, very usefull for seeing where things wer occuring

I mapped my ride to work by monitoring the gear change function

 

[PhilBoy]

My 2021 1250GS has a BMW Nav5 and on one of the screens you can pull up live data from the bike. One of those is coolant temperature.

I noticed today when riding along (about 20C ambient temperature) the coolant temperature is constantly changing. It will drop to high 70s, then slowly increase to low 90s in the space of maybe 2 minutes, then drop quickly (in 20 seconds or so) back down to high 70's. Repeat indefinitely.

I don't think the fan is coming on. That kicks in in the high 90s normally, and when stationary it brings the temp down by maybe 5 degrees in a couple of minutes even in 35+ air temperatures.

Is this cycling from high 70s to low 90s normal? I've had the bike since new and there's every possibility that it has always done this. I've never really looked before as I didn't have the temperature showing on that particular screen until recently. And if it didn't have the temperature gauge I would never have known, so I'm not overly concerned about it.

If anyone fancies a little task while out riding, it would be interesting to know if they all do this.

Think you’ll find this is the thermostat opening, fan coming on high 90s spot on. All is normal. Just ride and enjoy.

 

[DJ123]

It's normal. Fan kicks on in high nineties, which is usually when travelling at slower speeds/in traffic.

 

[Mr Bean]

According to Google AI, the stat starts to open late 70' s and fully open early 90's

 

[Ectopic]

Thank you all.

 

[Dougie Danger]

Thank you all.

I had an irregular temp issue. Check that the radiator fins are not blocked. Shine a torch from one side and you will see if and where it is blocked. I couldn’t believe the amount of crud that had built up over a period of time. Lots came out from between the fins when I cleaned it with a pressure washer.

 

[Ectopic]

I had an irregular temp issue. Check that the radiator fins are not blocked. Shine a torch from one side and you will see if and where it is blocked. I couldn’t believe the amount of crud that had built up over a period of time. Lots came out from between the fins when I cleaned it with a pressure washer.

Thanks. Mine are all clear.

 

[Hann]

Is this cycling from high 70s to low 90s normal?

Did you see this similar thread which might reassure you it`s normal?