Coolant loss

[FAF]

Hi all - over the past year my September 2020 gen4 has been in 3 times for various checks/work. On each occasion the report identified the coolant was low (and they topped it up). I've just been installing a new set of headers/pipes and noticed the level was down to Minimum again. It seems to loose the volume (from Max to Min) every 1000 miles. I've never had that on new/relatively new bikes (or cars)! I can't see any leaks, and oil has no emulsification. Anyone else experienced this? Might be another trip back to BMW

 

[JamieMac]

Mine is the same. These engines run very hot when in town etc. The coolant bottle allows for expansion of the coolant so when the engine cools down it can draw the coolant back into the system. There is a limit though. When it gets really hot, the coolant fills the bottle and the rest is expelled down the black overflow pipe much like over filling your petrol tank. Every bike I've ever owned except my Ducati 1098 does this. On the Ducati, the temp never gets above 80c so never fills the bottle. I wish all bikes ran in the 70c's as it's the perfect operating temp for power and doesn't wear your oil but when you're pumping out 200+ bhp the engine is going to create a lot of heat and the resultant oil/coolant issues. The MotoGP bikes at 300BHP are unreal for heat. Hope that helps. J

 

[JamieMac]

Checking coolant levels is like checking tyre, oil etc. I check every 250 miles at least. Tyres every ride. J

 

[fast_ryan]

Coolant Loss

My track only Gen 4 is the same. Just monitor the coolant level and top up when required.

 

[FAF]

Thanks Jamie - it does help! [But I never had to top it up on my gen 3, nor on 3 or 4 gixxer thou's I've had. I will keep monitoring it]
Cheers

 

[FAF]

Re: Coolant Loss

My track only Gen 4 is the same. Just monitor the coolant level and top up when required.

Thanks Ry

 

[mike g]

never had to touch mine in 7 years and 45000 miles (I do check it from time to time) and mine runs very hot unless you are doing 70 mph when the airflow keeps it well below 80 degrees, runs up to well over 100 if you are at town speeds, fan comes on but temp light never has

 

[alex]

I have seen that the Gen4 cooling is more of an issue than it ever was on the Gen3. It's like they just went the wrong side of OK when trying to squeeze as much weight out of the bike as possible.

Probably worth a more regular clean out with compressed air to keep the rad operating at peak efficiency (carefully mind).

 

[RickS1K]

Too early to say with my Gen 4, Gen 2 has never had issues. My Gen 3 S1R is a year old and I have had 3 conversations with BMW about the coolant... expecting a 4th come the spring when I start using it again....

 

[FAF]

Erm, can't seem to find any spec (propylene or ethylene) for what type of coolant to top up with? (not replace, flush, just top up)

 

[fast_ryan]

Coolant Loss

I just use Castrol motorcycle coolant.

 

[bowling]

Whilst mine was in getting a service, I mentioned the regular loss of coolant & the mechanic said on certain gen 4 the loss was due to the 1st seal on the water pump passing. Said the tell tale of this being the case is to look on the floor under the sump for drops of coolant. As there is a pipe which runs from the water pump, through the sump and out. This is to allow the water to run out, rather than mix with the oil should the 1st seal pass. Because they couldn't see any drips whilst it was in, they didn't do anything, but advised if I see any, to get it in asap. If 2nd seal goes oil will be milky & engine could go kaput!
I also noticed when cleaning a few months back, next to the header tank there was a white residue on the frame, perhaps these engines get that hot they can blow back out of the header tank?