Only ran about 15 miles, mostly traffic, and the bike ran consistently 1 bar cooler. However, it was running fine to begin with, and the weather is cooler this time of year anyhow. The fan never kicked on either. So it is hard to make a good assessment. Nevertheless, this cap DOES fit. The part number works for ToughOne or Stant.
If the the hoses are firm when hot = good system pressure and the radiator is full when cold = good recovery then you're onto a good thing. Plus the bonus of easier removal.
This was my first metric of testing, and it passed this. My concern is how it does in traffic/idle conditions. At 0.1 bar lower, it "could" run a bit hotter since there would be less pressure in the system, and thus a lower boiling point. However, the thermostat is going to control when the coolant moves, not the cap. So as long as I'm not creating too much pressure (ie, a 1.6 bar cap) then I should be good to go. Nevertheless, I'm consistently running a one bar cooler according to the dash, and I'm not seeing any big swings in temp like I saw before. Remember though, I didn't really have a problem before, and I wasn't overheating. But I did notice big swings in temperature at times, which made me suspect of the cap.
Keep us informed please. I'll be following suit if the new cap makes the system work properly. Any chance of a long idle test? Should be able to see temps rise and test the recovery/overflow of the new cap.
Rode it home from work tonight (30 miles) and let it idle after I got in the driveway. After about 15 minutes, the temp climbed up to here: This is where the fan kicked on. It quickly brought it down to here: And thus was the cycle. Keep in mind, the fan brought the temp down to where my bike WAS running before the cap change. In other words, what you see on the "after" photo was my standard operating temp prior to the cap change. When running, with the engine in the breeze, the bike runs three bars cooler than what is pictured here at a dead idle. Overall, I'm going to call the swap a success. As always, your mileage may vary. I'd love to see a few others make the swap and see if they get similar results.
The dash temperature is showing the air temperature in the airbox, not the temperature of the coolant in your radiator. The airbox temperature sensor is on the same side as the fan, so there is possibly a minor cooling factor there, but more likely that when the fan is blowing, the heat radiating off the engine into the airbox is blown away by the fan and this would have the effect of dropping the dash temp. I would expect the coolant temperature of this engine to run somewhere in the 200F - 250F range, particularly in the top end of that range at stationary idle when the fan is triggered.
This sounds like a thermostat issue, do we have a replacement part number for a good thermostat? Hey also, I notice your scratches. I put a phone screen protector on mine, stays on fine.
I'm talking bars at the bottom, not digits on the screen. The bars on the bottom are your engine temperature guage. I just flipped it to show that so people could get a rough idea of the ambient temperature when doing the test.
Not exactly. If a cap isn't functioning correctly, it won't allow proper exchange between the radiator and the tank. This could also introduce air into the lines, or rather, not allow air to escape the system. Any of this would throw higher or inconsistent operating temps. And I've been meaning to throw a protector on that screen for months. I just never seem to remember to pick one up.
Hey Mag00, I'm a bit intrigued as to why your pointing to the thermostat? (just a question!) The pics are the same as my terra, with the fan pulling it back under control. Maybe the gauge is not linear? At running temp and when the fan kicks in, I have turned the bike off and I can't hear or smell anything like a engine burning up, as they do. (old school techniques!) Would you kindly post a pic of when your fan kicks in! Regards pc[/quote]
Assuming these caps were precise (which they aren't) going from a 1.1 bar to a 1.0 bar would lower the boiling point of your coolant about 4 to 5F. Using a 50/50 coolant mixture boiling point with 1.1 bar cap is around 260F & 1.0 bar is around 255.7F - this should be a non-issue. Thanks for finding the parts.
The thermostat works on both ends of temp variations. When your engine is cold, it stops the flow of water to let the engine warm up. Then when hot, it opens and lets the water from the allegedly cooler radiator flow and cool the motor, RD, you said the fan kicks on at a certain amount of bars, but also stated that it ran 3 bars cooler in the wind than what was pictured. That is not how an engine cooling system is supposed to work, that thermostat and radiator should keep the motor temp constant. With the fans kicking in late, I can see it running warm for awhile, but to have such a mood swing is not normal or healthy for an engine, it is like running without a thermostat so to speak. I don't know what the actual temp of our engine and thermostat are, and this may be the normal ranges, but mine does not drop that low, and yes, my fan comes on a bit late, in my opinion, when in traffic, which would be a sensor calibration issue. Now I am wondering if the ecu has params that can be adjusted. Hmmm. The running cool in the breeze indicates a sticky or poor thermostat at first blush, that is why I mention this. Knowing the quality of cap, very possible we got junk thermostats. And knowing this, it is a cheap insurance fix as in preventative.
Fair enough. I'm used to air cooled motorcycle engines, and seeing running temps fluctuate. It is possible that I still have some air in the system. Let me shake this thing out for a few more days and I'll report back.
After the second trip back to the dealer for my overheating issues, they replaced the radiator. The official diagnosis is that it was a faulty thermostat. They said that the thermostat is buried in the radiator, so they just replaced the entire radiator (?!). This sounds very strange to me, never heard of a thermostat buried into a radiator before. Anybody have any input on that particular issue? The bike is not overheating at this point, but it stills run a little hotter than I would like.
This would make sense as several owners have had their radiators changed out to correct o/heating issues. I searched the parts & service manuals using the words "thermostat" and "thermostatic" and the only reference was the troubleshooting section where it tells you to replace the thermostatic valve if the engine is o/heating or too cool. Probably a generic t/s guide.
