I posted this last night but it looks like it got lost in the update perhaps?
Yesterday I drained the old coolant out of my new-to-me 2003 VFR. Flushed twice with distilled water, then while on the sidestand, added Prestone green 50/50 into the filler neck above the right radiator to almost the top. Then filled the reserve tank on the left side to almost the top line.
I let it idle with the two caps off, revved it a few times, and shook the bike a bit while sitting on it. When I revved it, the coolant would sometimes dribble out the filler cap on the right side.
The service manual says that the thermostat should start to open around 175*F. Well, I got to that temperature and beyond, and realized I didn't know what to look for to know if the thermostat was opening. Any suggestions on this??
Then the temp went up to 223*F, and the fan still never kicked on. It was late already by this point so I capped it up and left it for tomorrow (today).
In the post yesterday, spud786 suggested that there is an air pocket in the left radiator keeping the temperature sensor from kicking on the fan, and that I should rock the bike very far over to the left to try to dissipate it. I will give that a shot tonight.
Any other suggestions? If it ever stops raining here, I'm going to ride it around and see if that loosens it up.
When the radiator cap is off, nothing will happen with the reserve bottle.
When you start the bike, the right radiator should get hot quickly, the left radiator should stay cold until the thermostat starts to open at 180. Usually, the thermostat will start to open, then close again as the cold coolant in the right radiator brings the temperature down. After a few cycles, it will stay open, and the coolant should be moving pretty rapidly when you blip the throttle.
The radiator fan should turn on at @220 and off at @200.
Try opening the radiator cap and observing again today. The air may have cleared itself by now.
[image: View Post]jeremy556, on 28 October 2009 - 07:36 AM, said:
Fill it slowly on the side stand.
When the radiator cap is off, nothing will happen with the reserve bottle.
When you start the bike, the right radiator should get hot quickly, the left radiator should stay cold until the thermostat starts to open at 180. Usually, the thermostat will start to open, then close again as the cold coolant in the right radiator brings the temperature down. After a few cycles, it will stay open, and the coolant should be moving pretty rapidly when you blip the throttle.
The radiator fan should turn on at @220 and off at @200.
Try opening the radiator cap and observing again today. The air may have cleared itself by now.
Does the fan use the same temperature sensor as the LCD readout does? Or is it different? Since I had the cap off for a while as it was getting hot, I'm wondering if the LCD read out the "hot side" and the fan read the "cold side" and didn't come on?
[image: View Post]elwray, on 28 October 2009 - 07:38 AM, said:
Does the fan use the same temperature sensor as the LCD readout does? Or is it different? Since I had the cap off for a while as it was getting hot, I'm wondering if the LCD read out the "hot side" and the fan read the "cold side" and didn't come on?
No there is a thermoelectric switch that is on the top of the left radiator - it gets hot then competes a circuit to ground and it kicks on the fan, just a ground loop switch, you will see the ground wire connected to it. It grounds out to the frame.
[image: View Post]HispanicSlammer, on 28 October 2009 - 08:00 AM, said:
No there is a thermoelectric switch that is on the top of the left radiator - it gets hot then competes a circuit to ground and it kicks on the fan, just a ground loop switch, you will see the ground wire connected to it. It grounds out to the frame.
So if I had an air bubble trapped at the top of the left radiator like spud786 suggested last night, then the fan temp sensor wouldn't see much temp change and never kick on.
I'll pop the cap and give the hoses a good squeeze all around and shake a bit and see if I can't get these air bubbles out. Then I'll run it up to operating temp with the cap back on.
The only reason I'm really so concerned with it potentially not functioning is that the bike wasn't exactly taken care of very well by the prior owner. It wasn't abused, but wasn't given the attention it deserved.
The temp sensor for the fan is in the very top of the left rad. The temperature that you see on the LCD is coming from the ECT sensor at the engine block.
So I should punch a small hole in the top of the left radiator to bleed the air out? (kidding) Any shortcuts on getting it out or just tip it to the left really far and blip the throttle? It should be dry here tomorrow (got my fingers crossed) so I'm going to try and take it for a spin, maybe shake some loose.