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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #1
As some of you know, I have a flashed ECU and the fan kick-on point is 190 degrees. Normally, the fan will kick on and bring the temperature right back down to the 180s range and it'll shut off. Well, I was riding yesterday and noticed that the temperature was rising quite fast. And it was definitely exceeding 190, even with the fan kicking on. I let it sit and it went from 190 to 196 with the fan running on full. Great. That being said, it would stay in the 170s to 180s while riding and moving.

I check the coolant level, and it lower than I'd want, but still enough in the reservoir that it wasn't an issue. I checked the radiator cap, and the fluid was to the top, so now I'm left wondering whether this is a magic air bubble that appeared in the system, a water pump that's slowly on its way out, or a fan that is dying. :crying
 

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Currently using pedals..
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Was 196 the highest temperature it reached? I wonder if a thermostat would slowly begin to fail as well. You could start testing things, but I would wait and see if it begins to get worse and temperatures start to become higher over time. Then I would certainly begin to investigate.

Did you try to bleed the system at the bleed bolt on the pump to see if there was any air?
 

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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #3
Was 196 the highest temperature it reached? I wonder if a thermostat would slowly begin to fail as well. You could start testing things, but I would wait and see if it begins to get worse and temperatures start to become higher over time. Then I would certainly begin to investigate.

Did you try to bleed the system at the bleed bolt on the pump to see if there was any air?
196 was the highest I let it go before I shut it off, but it was quite apparent that the fan was not enough to stabilize the temperature. It just kept increasing as I was sitting at idle. I was lucky I didn't get stuck in traffic
I haven't had time to do further testing, checking the bleed port and rocking the bike back and forth to check for air bubbles at the radiator fill point is my next step. Probably futile, but it's the easiest thing to do and it doesn't involve spending money.
 

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Yikes, I understand more now. I'd image the speed in either of the fans would be noticeable if it where failing. However, I love to buy things marked off at $Free.99 :lol

Good luck, I hope it's simple!
 

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IM THE BRONZE
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Two things I would suspect would be as mentioned thermostat failing and trying to stay closed or a bad temp sensor.
 

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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #8
I would not call this normal, not with a fan kick-on point that is lower, this just started happening and the temperature outside isn't hot enough for me to correlate it with that. The fan should be enough sufficient to, at a minimum, stabilize the temperature. Normally, while sitting at an idle, the fan was able to move enough air to slowly decrease the temperature. Instead, the fan was going full blast and the temperature simply continued to rise by 6 degrees before I shut it off. I will observe what it does when I ride it again, hopefully today was simply a fluke.

If it were a stock ECU, it would be normal, because the kick-on point is significantly higher. However, even when it kicks on, the fan is enough to stabilize and decrease the temperature.
 

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You should listen to me. No, seriously, listen to
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"I was riding yesterday and...it was definitely exceeding 190, even with the fan kicking on. I let it sit and it went from 190 to 196 with the fan running on full. That being said, it would stay in the 170s to 180s while riding and moving."

This isn't completely consistent. Were you not moving, ex. in traffic, when it got high? It's rare but every once in a while I'll ride through an area where I can feel that it's suddenly hotter and I can see my temperature go up somewhat. Might you have encountered one?

Beyond that, the best I can offer at the moment is to keep an eye on temperatures and levels.
 

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I think what is saying is that while he is moving, it's not much of an issue as it is when he is at idle. This is when it would become an issue, right Nick?

What I would try to do next as well is let it idle and see if temperatures exceed 220 degrees. I live 1-2 hours from him and temperatures are very similar here. When I let mine idle up to temp, my fans start up at 190 and immediately lowers it to the middle to high 180s, I'm using water wetter. So to see the temp climbing like that may suggest there is an issue that may progress into a more serious issue to the point where he wouldn't want to ride around Austin, especially getting caught in stop and go traffic because of over heating.

This is what I'm getting from all of this, correct me if I'm wrong.
 

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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #11
I think what is saying is that while he is moving, it's not much of an issue as it is when he is at idle. This is when it would become an issue, right Nick?

What I would try to do next as well is let it idle and see if temperatures exceed 220 degrees. I live 1-2 hours from him and temperatures are very similar here. When I let mine idle up to temp, my fans start up at 190 and immediately lowers it to the middle to high 180s, I'm using water wetter. So to see the temp climbing like that may suggest there is an issue that may progress into a more serious issue to the point where he wouldn't want to ride around Austin, especially getting caught in stop and go traffic because of over heating.

This is what I'm getting from all of this, correct me if I'm wrong.
The issue presents itself both at low speeds and at idle. If I'm on the highway, it does not overheat. If I'm going below 50mph, I can watch the temperature jump up. If I'm idling, it will simply continue to climb, even with the fan on. Which makes me think that either the water pump itself is starting to give out, or the fan on the radiator is on its way out.
 

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I know things... A lot of things.
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So does this happen consistently then? If you would cold-start the bike say, and let it idle until it reaches 190°F, will it still keep climbing past 196°F? If these were isolated incidents, did they by any chance happen, when suddenly hitting traffic (or other conditions forcing you to go near idle speeds), after a prolonged ride at higher speeds? If you're just seeing that some times the coolant temperature will drop faster than others, then that might well be normal.
 

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You should listen to me. No, seriously, listen to
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I rigged up a switch to manually turn the fan on while idling in the garage during throttle synchronization. Without it the temp will run up to 220 °F where the fan comes on. With it installed and the fan on, the temp will sit at 170-175 °F, the thermostat temperature. I don't understand why yours should be different.

Might your radiator be blocked externally or internally? Alternately, are any of the undercowling parts missing?

My fan is so quiet that I painted every third blade white to make it easier to check that it's running.

Don't know if it's of any use but note that you can force the fan on by unplugging the ECT. But the display will then read something like "---" and there will be a C15 error.
 

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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #14
So does this happen consistently then? If you would cold-start the bike say, and let it idle until it reaches 190°F, will it still keep climbing past 196°F? If these were isolated incidents, did they by any chance happen, when suddenly hitting traffic (or other conditions forcing you to go near idle speeds), after a prolonged ride at higher speeds? If you're just seeing that some times the coolant temperature will drop faster than others, then that might well be normal.
Nope, wasn't after isolated incidents. It happened every time I was riding, whether it was after a leisurely pace at 50-55mph, after riding the highway, sitting at every stoplight (including just pulling out of a parking lot and riding some side roads), and when I arrived back at home. It was sitting and had dropped in temperature, and I let it idle to test it. The temperature rose, the fan kicked on, the temperature continued to rise, and I shut it off.

No body parts are missing, and everything lines up. This just happened starting yesterday, it was never an issue prior to this. The noise of the fan might indicate that it is the culprit. Or, something is blocking the cooling system.
 

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You should listen to me. No, seriously, listen to
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"The noise of the fan might indicate that it is the culprit."

Run through this thread. It sounds uncomfortably similar to yours.
 

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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #16
I'll see if I can capture a video with audio that shows the fan noise, so you can compare it to yours.
 

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I know things... A lot of things.
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Have you perhaps noticed any difference in fan flow rate? I mean, on a (relatively) hot day you can feel the fan kick on due to the flow of hot air hitting your legs, even if the background noise of a busy street prevent you from hearing it. Has this effect lessened in any way? Have you perhaps noticed any change in the coolant level variation in the expansion tank, like it might be rising higher than before when the engine warms up (although with the temperatures in question, the effect might be small)?
 

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Captain Obvious ... because obviously it’s obvious
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Discussion Starter #20
I tried testing it again, but it was about 8-10 degrees cooler than the day I had no issues. It went up to 194, the fan kicked on, and it brought it back down. The fan noise is not abnormal, no sound of it striking against the radiator like the thread @BillV linked. I am hoping for another 90 degree day so I can test it, and see if it replicates the issues. Perhaps the fan is simply aging, and is unable to move enough air once the ambient temperature is too high. Time and testing will tell.
 
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