I started the bike the other night, let it run for less than 10 mins, when I looked at the bike there was a puddle under the overflow and when switched bike off there was a gurgling sound coming from the coolant system for around 30 seconds and you can feel the vibration (Engine off) Anyone heard of this before? Just popping out to check a few things over so any suggestions would be great
What bike and how long was it running? The gurgling could be as simple as an air lock, or it could be getting pressurised which would point at a head gasket. If you start the bike, have a feel at the coolant hoses to see if they firm up at relatively low engine temp or after a short time. I’m doing one currently that firmed the hoses up within minutes at less than 40 degrees. Was also causing bubbles to be blown into the expansion as it had lifted the pressure relief on the rad cap.
It's a monster 1200s, it starts gurgling once it's warm maybe 5-10 mins, once engine switched off it starts gurgling withing 5 -10 seconds and lasts about 30 seconds. Fans are coming on at correct temp. Coolant drip from up behind EVAP canister but can't see from where..not sure if hoses are firming up though, will try that next
is temperature reading behaving as normal? Is it taking longer to come up to temperature? plus I know I'm stating the obvious, have you checked coolant level?
All looks ok, coolant is at max, warms up in the time you expect. Bike ran fine last time it was out, no issues, now this.
I saw a similar post on another Forum, but with no conclusions, Neil will know how likely/how common head gasket failure* is - if this was a car i'd be suggesting partially blocked water rad, worn/inefficient water pump, cavitation at water pump for some reason or air being introduced somewhere. I don't think it's thermostat related but can't be fully ruled out. If * then early stages, as, depending how gasket has failed - oil and water levels and normal running temperatures can change/become erratic as gasket sealing deteriorates. Also - looking at your first post, when was last time you ran the bike? - two other thoughts are rad cap not achieving designed-in pressure, cooling fans coming on too late, symptoms do sound like the last one going by continuing events after engine shut-off.
Bike was last used few weeks ago, so whatever the issue is its just recent, fans are coming on at 103 deg, i am tempted to its drawing air in somewhere, there is a drip behind the EVAP but cant find where without removing parts, bike now booked in to go back to shop, i have only done 400 miles on the bike and only had it since Sept, 6 years old but not used which looks like that may be part of the issue.
The same happened to me on 2014 Monster 1200. I exchanged the radiator cap to new and bubbling issue got solved.
It would be great to get an update on this for other owners, did you resolve this @NSR500 ? I forgot to mention that overfill of coolant system being another possible cause.
