COMING SOON
The problem to overheating 2015+ S1000RR is a two-part issue. Most of the bikes that do this are ridden very hard at high speed and notice a mysterious coolant loss that can’t be replicated at low speeds. These same bikes are typically in warmer climates, although we have seen some in New England as well.
First, the main issue is poorly torqued torque-to-yield factory head studs. We have seen 2015+ RR’s with head studs torqued to less than HALF of the factory spec. This leads to head lifting and breaking of the head gasket seal. After this happens, pushing of coolant is common.
The second issues is some of these bikes were shipped with poorly machined heads and still have a grooved head surface. The grooving was so bad the motor was able to ingest coolant WITHOUT breaking the headgasket. This is something a proper headgasket will never make up the difference for. We had to send the head to a machine shop to have it decked flat and then purchased a thick head gasket to make up for the clearance.
The fix to this issue is as follows:
Machining the head flat, custom headgasket and adding NON-Torque-to-yield head studs torqued properly. Doing this can provide a small compression bump thus increasing horsepower, while allowing the bike to keep coolant in it without issue. When going down this road, it is a good time to add our proven custom race camshafts. These are proven 10-15WHP over stock while providing no loss in bottom end power.
What we know:
– We have not isolated what years or specifics to the bikes, it seems random.
– It happens to modified and NON-modified motorcycles. PC5/Bazazz/Flashed all have potential for issue.
– It is more prominent in hotter climates (Middle East, Florida, SoCal etc)
– Water Wetter or Engine Ice both help, but are a bandaid fix.
– The TTY bolts on the factory head are less the optimal. Factor in that TTY bolts will stretch with heat and high cylinder pressure along with under factory spec torque from the factory and this is the result. Using head studs vs bolts on the bike makes this problem go away.
– The heads do not “warp” (unless overheated) and the headgasket doesn’t break. The bike lifts the head and pushes coolant into the reservoir and out of the bike in most cases.
– The part #’s are the same from 2014 to 2015 on the S1000RR. The 10-14 bikes never had headgasket or head stud issues.
– The head is revised on the 2015 versus previous years.
– Some bikes with SERIOUS abuse, still do not leak, including some of our highest HP bikes. We are talking 100% stock, unopened engines. These bikes are frequently doing 200MPH at 200+WHP.
How to test it:
– Combustible gas strips in the overflow while revving bike to 8-10k rpm (small revs do not mix).
Why quick fixes work for some, well; temporarily:
BMW’s official fix for this is a new pressure cap. We agree that bikes raced should have a slightly stronger cap then the factory one, even stock. However, this is not the fix. Adding fresh coolant, burping, will get the bike back to normal in most cases and is fine for casual cruising. Adding water wetter / engine ice or other similar products helps remove bubbles and creates a bike with less heat issues in general, even on the stock thermostat. When the bike cools and the bolts aren’t hot and stretched it will temporarily not congest coolant. Fresh coolant and say water wetter, will reduce the building from the combustible gasses in the coolant which do not cool the surface area of the head. However, the next time the bike lifts the head and the bolts stretch enough to let coolant seep by, it will happen again. Some get away with it forever, but the issue comes with the bolts and in some cases, head’s surface (your model may vary). You can’t safely re-torque TTY factory bolts so pulling them and studding is the only option.
When water wetter is introduced it reduces these combustible air bubbles in the coolant, the combustion gasses from the studs lifting entering the coolant is essentially pushing air or bubbles into the system. The water wetter reduces, but does not eliminate, the problem. A large mass of these bubbles and air will push coolant into the overflow and create hotspots on the head from the lack of surface area being cooled, resulting in an overheating problem. In some cases when coolant continually pushes out of the overflow the bike will have next to no coolant left over and overheat as well.
What we don’t know:
– Why some bikes do and some bikes don’t.
– What heat, stress level or power level lifts the head.
– Why some bikes are torqued well and others are not.
– Why some heads are grooved and clearly machined wrong and some are perfect.
SATISFIED CLIENTS MAKE US HAPPY
Hi,
I have a new 2018 S1000XR and am based in Bangkok Thailand.
It is 2 months old and after 3000 km I started to get this same problem.
I don’t track the bike, but it is ridden quite hard in ambient temperatures above 35 deg centigrade.
The bike exhibits this same problem, venting coolant from either the cap or overflow and overheating.
After removing the faring and checking coolant in the radiator (allowing the bike to cool first obviously) there seems to be very little coolant in the radiator even though the expansion vessel still contains coolant to normal levels. The dealer is suggesting the cap is the problem, but the symptoms you describe seem so similar, my concern is that the BMW ‘fix’ is all they will do. I’m an Englishman in Bangkok, and language can always be an issue, especially when the dealers don’t want to acknowledge problems or actually investigate properly – it’s an admission of a bad bike and they don’t want to ‘lose face’.
Are you aware of any recent bikes with this engine (even the lower tuned XR engine~) exhibiting this problem?.
Regards
Mike HOGG.
Email us at sales@brentuning.com
Hi,
Very interesting. A friend and I both run S1000RR’s in race cars, and we both struggle with loss of coolant, they are typically out of coolant before the races are over. The engines obviously run very hard, close to the redline for up to 15 mins. This weekend of racing was cold (~10C), and we saw the overflow happen at as low as 40 C coolant temperature!
The strange thing is that we run 2012 and 2013 model engines, but you say the problem started in 2015. Are you sure? Our problem seems very similar to the one described here!
Thanks for your help.
Email us at sales@brentuning.com