Temperature swinging erratically
 

The temperature on my 06 F4i swings all over the place recently for some reason.
I will start driving it and it will go from 95 to 180 and everywhere in between. this happens weather I am stopped driving idle full throttle. It is really bothering me. The fan seems to kick in at the right temperature and cool down the engine but the reading just goes crazy. Help!:icon_doh::icon_denk::icon_denk:

You say the "reading" goes crazy - does that mean you think the guage is wrong, or the actual engine temperature is fluctuating.

Legitimate temp fluctuations could be several things but start by making sure it is full of Anti-Freeze. After that the possibilities are that the thermostat is goign bad, or an outside possibility it has a air bubble in the system (although I have NEVER had that happen in any of my vehicles).

If she's got coolant I'd check the connector on the thermo sending unit first. When i swapped mine out on the F3 for the F4i gauge swap I noticed it's just a push on plug.

Could be coming loose, which would cause erratic temp readings I'd think. I'm pretty sure the thermostat wouldn't have anything thing to do with the reading on the gauge. The thermostat in the radiator is purely mechanical and when it goes, an overheat is usually quick to follow. And the gauges get the temp from the sending unit

I would check the main ground By the Fuel pump plug and the connectors at the dash.
My bike was doing the same thing and I found it was the connection at the dash

Thanks for the great suggestions. I will try those today and see what I find. It is definitely not a problem with the thermostat because the fan kicks on when the bike gets too hot (220). but the temp reading will still be bouncing all over.
I will let you know my findings.

Sending unit for coolant is most likely shot. Sounds like its gumed up and has a hard timing reading the temperature.

Well the weirdest thing happened. I took off the front to check the wires and started it up and it read perfectly. I dont know why. Hopefully it will stop raining soon and I can ride it and see if it is still swinging around but it worked perfectly today.

Hmm check for wires. Sounds like either connection was loose or a wire is loose some were. Pull on the wire when the bike is running and see if it moves at all.