Hi all, Wondering if anyone else has experienced this - after riding through central London, and the coolant temperature getting up to 103-104ºC, I turned off the engine and heard a high pitched whine and bubbling sound. Almost like someone blowing through a straw. Is that normal? The coolant temp. doesn't seem particularly high (the manual says below 120ºC is not considered high), so I'm wondering if there's another problem. I made a quick video with the sound: Dropbox - Video 03-05-2016, 08 15 15.mov Cheers!
Would that be from over-filling with petrol? I filled up to the bottom of the neck last night, and then rode ~20 miles today so would be surprised if there's too much petrol. There was a drop of something on the floor, which would make sense since it was roughly where the rubber pipe comes out. Thanks
No, not overfilling. I'm not familiar with the tank breather arrangement on the 821 but on many Ducatis there is a rubber seal at filler and it can make a squeaking noise as the pressure equalises in the tank after switching off. It seems to vary from bike to bike, some do it and some don't. Sometimes it is more of a chirp.
When it next happens, try opening the filler cap to see if there is a vacuum in the tank for to a blocked breather. If you get a slight woosh noise as you open the cap that'll be the pressure equalising and you know that you need to get a compressed airline on the breather to blow out any grit and gunge and to check that it's not pinched somewhere.
Oh right, so if the breather (that's the tube hanging down, near the horn?) is working correctly there shouldn't be a vacuum; but if it's blocked, then there will be?
Can't help wondering if it's the coolant returning to the main tank from the expansion tank. As I understand it, the system is pressurised by the pressure cap, which allows the pressure to rise to the level stamped on it. Excess pressure is vented to the expansion tank along with some coolant, which then returns to the main tank when the system cools down.
Yup, that's correct, though I didn't realise your model was water cooled, so the other replies regarding the rad are probably more likely if it's a bubbling sound. Just listened to your recording and that definitely sonds like coolant bubbling. It's definitely not right and sounds like it's the rad over pressuring. Have you lost any coolant? If you have you may have a blown head basket that is allowing the coolant system to pressurise with exhaust gasses. Had the same thing happen on a couple of cars in the past.
Not really a good idea, if it is pressurised then the steam will be >100*c and will burn. better option is to wait till its cooled down and then check the level, if it is low then there are a few things it could be. Either head gasket, coolant leak or just low level from new? I've seen a few times over the years where a rad cap has been so called carefully removed and it was like a small bomb going off..
Let the bike cool see if it has lost water At the main pressure cap not the header tank cap , top up if nessasary and run bike with cap off see if there's a constant stream of bubbles coming up , this is combustion gases getting past head gasket , you can buy chemical testers that go over the rad cap and test for carbon monoxide for 100 % confirmation . You say the guage does not seem to be getting hot , can you confirm the cooling fan is working , is pressure cap Spring good .... no small nicks in any of the cap seals
That is not normal. I experienced the same thing recently after removing the radiator cap. After riding and shutting bike off the coolant sounded like it was boiling , boiling sound coming from the coolant reservoir bottle(touch the bottle cap u will feel it) also vent hose in the bottom was smoking and coolant was dripping slightly. My boy Ralphy who is a super gifted mechanic helped me figure out why today. He suggested to check the rad cap since that's the only thing I touched. We looked at the radiator caps seal to make sure it was good, I said it looked good and he immediately noticed the surface of the seal(lower most seal) had metal deposits, it came from the radiator side where the seal sits. On the radiator side where the seal sits there were also signs of uneven and bumpy surface. so we cleaned the seal of all metal deposits it wiped off pretty easily, now on the radiator side we had to use emory cloth (can use a very fine sand paper also, has to be fine no coarse grits) and smooth out the surface.. Placed the radiator cap back on. Road tested and boom!!! No more boiling coolant!!!! What was happening is since the lower seal wasn't sealing properly , it was letting hot coolant and vapors in to the coolant reservoir bottle heating it up all the time while riding. normally only happens for a duration when pressure builds up then compresses the spring and lets the pressure out, and closes back up to seal once pressure is relieved. Hope this helps, Kudos to my boy I bet if I brought it to the dealer they would of just started changing parts eventually changing the radiator and would of told me that was the problem, my bike is out of warranty!!!!
