TEMP LIGHT sometimes comes on and off when idling.

[Bip]

VS800 Intruder 1998 "Temperature Warning Light":

Comes on after 30 minutes of riding. Sometimes when moving in slow traffic or idling. Comes on with radiator fan running or not. Does not stay on.

Replaced coolant (green 50/50 antifreeze for aluminum motorcycle engines, coolant was not low). Tested and replaced thermostat (old and new thermostat were both good, checked with a meat thermometer suspended in heated water on stove ). Changed oil and filter. Oil is at the top of the mark.

Motor never pings and runs GREAT.

I'm thinking a smashed wire shorting to the frame. What are your thoughts?

[hillsy v2]

Have you tested the temp sensor?

[navigator]

Did you purge the air with the bleeder screw on the frame when you refilled it?

[Bip]

Did you purge the air with the bleeder screw on the frame when you refilled it?

The light started happening after the oil change and BEFORE the coolant change. I then drained the coolant with the screw at the bottom of the frame with the radiator cap off. Replaced the thermostat, then reinstalled the frame screw. Refilled the radiator, starting the bike every few seconds till I could not add any more coolant. Then sealed with the radiator crap. If it had air in the system, would the light come on in 15 minutes with temperatures in the mid 90's? It takes about half an hour and never comes on the highway.

[Bip]

Have you tested the temp sensor?

I have not tested the temp sensor . The say the sensor will light the temp light if it is grounded. I think I need to follow to sensor wire(s) to see if smashed and intermittently grounding.

[Bip]

I will test the sensor also.

[navigator]

if air is trapped in the system, it is possible to create steam after 15 minutes. the frame air bleed screw is on the left down tube just below the neck cover. Be careful not to break it, it can snap easily, it is just a hollow bolt. loosen it until water weeps out. No need to remove it, just crack it loose.

[Lechy]

You said you sealed with the radiator crap, did you use liquid or powder sealant? the powder does not dissolve and will block your radiator. The cores of a bike rad are a lot narrower than those of a car's.

[Bip]

Sorry. I meant to say the radiator cap was reinstalled. No additives we're introduced into the system.

[Bip]

Could not find any wires grounding ouy so I ordered a new temp sensor. Should be here in a few weeks. I update when installed.

[Bip]

The new and old temperature sensor tested the same. The new and old thermostat tested the same. Flushed system with pure distilled water. The new temperature and thermostat were installed. Burped the system thru the temperature sensor port. The temperature light still sometimes comes on when idling, not always with the fan. The fan will cycle when idling hot. Don't see any smashed wires. A Harley guy said not to worry about it.
I'm at a loss.... Any advice?

[sgtcall]

Could you have a short at the light making it come on when you hit a rough spot or just general vibration. My neutral light would sometimes flash on and off for no reason, it finally stopped when the bulb burned out so I just didn't have a neutral light anymore.

[hillsy v2]

The new and old temperature sensor tested the same. The new and old thermostat tested the same. Flushed system with pure distilled water. The new temperature and thermostat were installed. Burped the system thru the temperature sensor port. The temperature light still sometimes comes on when idling, not always with the fan. The fan will cycle when idling hot. Don't see any smashed wires. A Harley guy said not to worry about it.
I'm at a loss.... Any advice?

The only other thing is the water pump itself - if the impellor is degraded / eroded and doesn't flow well at idle then the engine might get hot?

I had this on a KTM400EXC - the impellor pretty much had no vanes left. Also had it on a car (Chrysler Voyager) where the car would get hot at idle but be OK when moving.

This is the old water pump from the Voyager:


And I found a pic of the KTM impeller

[hillsy v2]

Looks like you can buy an impeller separately if it comes to that (#2) and they're not very expensive :





https://www.cmsnl.com/suzuki-vs800gl-in ... 749138a00/

[FallenAngel]

Also check the temperature difference between the top of the radiator and the bottom
Sediments collect at the bottom clog the tubes and hinder the cooling process
If the top is hot and the bottom is cold then you have a plugged radiator

I have suggested these in the past


It is one of the most useful diagnostic tools I have
This one has a probe that can be handy for some applications


Also The temp light comes on when the temperature is above safe operating range

[Herb]

I am not real familiar with these bikes but I have ran into a few things on other vehicles.

Had a car that the water pump wasn't working properly due to corrossion in the impeller housing. It was causing an over temp in the engine. The water in the radiator was cool because there was low water flow. The electric fan wouldn't come on because the sensor was at the bottom of the radiator. The problem was especially noticable at idle or low speed.

Btw, the corroded part was actually on the block of a GM V6 and to repair it I had to use JB Weld to repair the channel in the block.

Is there any chance that the fan is not working properly? I have had electric fans that were intermittant and wouldn't always come on.

[FallenAngel]

Herb made a very god point Does the fan work and turn on ??

[hillsy v2]

Herb made a very god point Does the fan work and turn on ??

He said the fan comes on.

[FallenAngel]

Herb made a very god point Does the fan work and turn on ??

He said the fan comes on.

OK
Found it in his first post

VS800 Intruder 1998 "Temperature Warning Light":

Comes on after 30 minutes of riding. Sometimes when moving in slow traffic or idling. Comes on with radiator fan running or not. Does not stay on.

Good sign the fan dosent stay on even while riding
My next question is
What is the engine temp when the light comes on
I might think about testing and or replace the temp sensor

Im still a little suspicious of the radiator

[Herb]

I have had electric fans that would come on when the vehicle was moving but would not start when the car was stopped...