Been servicing the bike including flushing the old coolant. I do remember noticing at the end of last year that the normal running temperature seemed to have crept up by a few degrees but nothing concerning. Forward to today and took the bike out for the 1st time after the coolant flush and definitely something wrong. Earlier last year the running temp was mid to high 80's unless I was sitting in traffic. Today it was low to mid 90s and then when I had to go through town start/stopping for about 10 minutes the temp went to 125-130C just before I got to open road and rode it home where on a fast open road it went back down to high 80's low 90's. Other thing I noticed a few times as I was watching it like a hawk I saw the temp just skip about 3-5C up or down. Not sure if that indicates anything (erratic pump maybe?) Servicing wise I've changed oil/filter, cleaned the air filter and drained the coolant. Flushed it 3 times with distilled water and filled with Motorex OAT red coolant : https://www.amazon.co.uk/dp/B00EO63ORW Ran it a few times over the last week in the garage getting it up to temp, squeezing air out of the bottom pipes and topping up the reservoir. I could see it getting up to about 95C and then dropping down to 90C (I assumed pump kicking in or increasing flow at that point?) and then getting it up to 125C to check the fan was kicking in. All seemed reasonable at that point. So what's my next best step for troubleshooting? Check and replace the pump or a faulty temp sensor or something else?
My 07s temp is around 82c on the open road but In a 30mph area it creeps up to mid 90s , hot days in slow traffic it'll get to 106c then fan kicks in . Your's seems to be running a bit too hot , what condition is the radiator @BeelzebubUK
Yep that's the behaviour I remember from early last year. Radiator is excellent. It had been replaced just before I bought the bike. No damage to it as far as I can see.
It could be the thermostat sticking shut, next time the temp is high just check if the rad is to hot to touch without burning yourself if you can touch it whilst temp is up it could be thermostat problems
Yes but only at about 120C which seems high? Only a single fan on this generation. That was just idling in the garage after burping it.
Sounds way too high to me @BeelzebubUK - thermostat 19300MCJ003 not opening, faulty temperature sensor 37870KRJ901 or both IMHO (using logic, rather than specific model knowledge/experience). EDIT - part numbers taken from fowlers and added to above FYI https://www.fowlersparts.co.uk/parts/4818775/cbr1000rr6-2006-e-kmh/thermostat
Thanks everyone. I think thermostat is going to be my next step. I just wanted to ride after all the servicing
Warmed it up in the garage again today and it warms up to 95C where it then dropped down to 89C so thermostat is doing something at that point but whether it's actually fully opening is debatable. Then it steadily increases until at 120C the fan kicks in. Which is odd why it only does it then whereas everyone I've read mentioning it says the fan kicks in around 105C. Which probably means the radiator sensor is out of whack and needs replacing. Radiator was hot though.....couldn't touch it for more than a second. Time to get the parts cannon loaded?
Yep I've ordered one and a thermostat with it as I thought might as well replace it too as I'll be there anyway. Hopefully one or the other will sort the problem.
I've seen this before with the temperature fluctuations, it is sometimes caused by an air lock in the cooling system. Best thing to check this is once the bike is stone cold, open radiator and check level. If necessary top up and gently squeeze bottom hose out of water pump and see if you get any air bubbles, top up again/repeat.
RR 2008 running 10w50: I use Honda coolant. My 1st fan kicks in @~102, the second @~106. Normal riding winter: 76~78 Summer: 78. Hot day (30deg) 80~84 Traffic the first fan keeps it under control between 105 (on) & 95 (off). After high speed motorway run, the second can kick. Thermostat can be sticky and partially opening so check it's full operation. I would also check the temperature sensor
When I changed the coolant I ran the bike with the radiator cap off and squeezed those pipes to get any air out and did it several separate times just to make sure I'd got as much air out as possible. Did check it earlier today cold and no air coming out. Should be able to change the thermostat and temp sensor at the weekend if they arrive on time.
Managed to change them both this evening. Will refill and test tomorrow. So happy I bought some flex-head ratchet spanners the other week. Was able to get to the bolt under the fuel rails/airbox with a few mm of turn Both just looked tarnished but ok. Hopefully it fixes it.
Looks like it is working and fully opening which may not bode well for my hope that it was the issue We'll see soon
Sadly after all that work it hasn't changed. Guess removing and checking the water pump is next on the agenda? Fan is still only kicking in at 120C - are there any other sensors I need to check?
Gutted for you. IMHO it’s unlikely to be the water pump - the fan should be coming on at a much lower temperature. So, as you’ve changed the sensor is it more likely to be an ecu issue as it must start/stop the fan?
