erratic digital temp. gage. HELP.

[Splinter]

On my 04 RS the temp gage has been running different than the norm temp of 83c. Showing lower temp readings up and down between LO and 78c max.and the fan has'nt been coming on. After coming back from a ride I let it idle in the driveway, the fan did'nt come on and it blew a bunch of antifreeze out the overflow.
So I guess the fan is not coming on because the temp gage is not reaching 104c when it would normally come on.
Has anyone out there had a simular problem ? Appreciate any feedback, thanks Ray W.

[4N099]

A bad thermostat?

[steventhechef]

The fan normally comes on at 103C and brings the temp down and cuts out at around 100C.

FWIW mine normally runs at 82 -85 on the highway and upwards to 95 in the city.

It is only at the traffic lights that it will come up to 100C +

[Splinter]

Thanks 4N099, but are you sure it is the thermostat ?

Thanks also steventhechef, and yes thats pretty much how mine was performing.
Also for some reason whether or not related its idling at about 1600-1700 rpm
which is also aggrevating the problem.
On my way home from the last long trip it started acting up, but I was not hung up at any traffic lights, I guess if I am I should just shut it off till I'm good to go.
I have a trip planned for monday and not sure if I should take a chance on it until I can get to a dealer, dealers are few and far between around here
Cheers Ray W.

[steventhechef]

I would suggest checking the radiator cap (when cold) for gunk around the rim and rubber. This would give you an idea if the system needs a clean and flush.

If so, that is a fairly straight forward job by removing the bottom hose and refilling the system and rechecking the fluid level while the motor is running. Remember the anti/corrosion/freeze additive.

Normally my 03 RS heats up to 52C (just off LO) in about 3 minutes and up to 83C in about 5 minutes.

tell us how you go..

If unsure ask your dealer..

[4N099]

Splinter, no not sure, I was just throwing something out there that may be a cause and something to check.

[TrippedOut]

I agree the low temp is a good indicator that the thermostat is stuck open and causing coolant to constantly cycle through the motor, but the spilling coolant part sounds like it could be something else. Aside from an actual leak the only two things that I can think of to eject coolant are too high of temp or pressure problems. Right?

I am no master mechanic, just throwing a couple educated guesses out there and seeing how I do.

[4N099]

I am no mechanic either by any way shape or form but a cooling system is pretty basic and if you are having overflow from your raddyator you are getting hot and something isn't doing it's job, usually it's a bad thermostat, that is normally what causes boil over in a car but it could also be a waterpump. Since your fan isn't coming on you might want to check your connections or the fan itself, it may be defective.

I don't know enough about this bike yet to really offer a solid opinion but so far everything I've peered at seems to be covered by plastic so it might pay to pull the fairing and have a really good peek at it naked. I've noticed that whatever the connection is at the front of the fuse compartment on mine is, that connection wants to ride at about a 35 degree angle all the time, never fully down flush. I am anal so I will probably rig a zip tie on it to hold it flush.

[TrippedOut]

Another issue I have experienced is dangerously low coolant level. The lack of coolant in the spot where the temperature gauge's sending unit is located can cause low temp readings on the gauge because there isn't any coolant there to measure. This could be your boiling over problems and low temp readings. If this were the case you can just add coolant, but still need to figure out why the coolant disappeared in the first place. Could be too long between coolant flush/service, leaky hose, blah, blah, blah.

Also, always check your radiator cap as I learned from this forum when I first got this bike and was having some problems.

[TrippedOut]

It sounds like the sending unit just isn't seeing that 103C that triggers the fan switch. After the bike cools I would check actual radiator and reservoir levels.

If all else fails I would just trade your bike for my '02 RS.