Q about the temp on my 92

When I'm out on the open road cruising at highway speeds the needle on the temp gauge barely moves slightly past C. It actually rises slightly and then falls back down and it does this over and over.

If I'm riding through town and/or stopped for a bit the gauge needle will rise into the middle and remain there. Once on the road it drops again.

All of the cars I've ever had always have a spot somewhere in the middle where the gauge never moves from. Except for the time I had a tstat that was stuck open. That happened in winter and the needle was always on C. Car ran like crap too and burned gas like a mofo. The bike runs fine which is why I'm stumped.

So the question is, is my temp gauge acting normal or is my tstat fried?

qman said:

When I'm out on the open road cruising at highway speeds the needle on the temp gauge barely moves slightly past C. It actually rises slightly and then falls back down and it does this over and over.

If I'm riding through town and/or stopped for a bit the gauge needle will rise into the middle and remain there. Once on the road it drops again.

All of the cars I've ever had always have a spot somewhere in the middle where the gauge never moves from. Except for the time I had a tstat that was stuck open. That happened in winter and the needle was always on C. Car ran like crap too and burned gas like a mofo. The bike runs fine which is why I'm stumped.

So the question is, is my temp gauge acting normal or is my tstat fried?

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Normally I would suspect a partial open thermostat. In my bikes case the same thing was going on for a LONG period of time.......before the coolant leak(elbows/o-rings) became visible with vitial colored fluid on garage floor in center-stand area. Prior to that, I had already fixed the known split at the top overflow hose, which will allow coolant to expand and go to overflow tank, but a split hose won't allow it it to be drawn back into system when cooling off. Sounds like something similar may be going on with your STeed.

Normal for the temp to rise when stopped on the 1100, I wouldn't worry about that part.
My temp is rock steady on the road though, have you checked the fluid level in the radiator?

You know what, I have not checked the temp. Will do pronto.

What is this "known split at the top overflow hose"? Is there a write up on it somewhere here?

When you check the coolant level at the rad cap, there is an overflow hose that's attached to the cap housing area. that hose makes a sharp bend towards the back of the bike to go to the overflow tank, and tends to split at that bend. it will usually crack within an inch or two of where it attaches to the rad, so take a look.

Also, I had exactly the same symptoms you describe on my bike. Tstat change didn't fix it, it turned out to be water pump related due to my neglect of changing the coolant for a long time. If you don't know the service history of the bike its possible you have a similar issue, but hopefully its something simpler and cheaper like the stat. If when the fan kicks on the system always brings the temp gauge back down to 12 o'clock, then your water pump is likely OK. In my case the other symptom I had was the fan wasn't bringing the temp down as well as it should. Sometimes it worked OK, sometimes it didn't, because of the compromised water pump.

qman said:

You know what, I have not checked the temp. Will do pronto.

What is this "known split at the top overflow hose"? Is there a write up on it somewhere here?

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This is the small hose that is connected to the thermostat housing . Just cut-off about 3/4 " and then re-connect it , whether it is leaking now, or not. Because if not, it probably will be soon.

But if you are part of the "If it's not broke, don't fix it " crowd, then don't touch it if it's not leaking.

Mark said:

Normal for the temp to rise when stopped on the 1100, I wouldn't worry about that part.
My temp is rock steady on the road though, have you checked the fluid level in the radiator?

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+1 . According to the gauge reading, on the highway it seems like the bike never warms up enough. But from past posts, they all act this way. Mine is the same. But the temp doesn't go up & down on the highway. BTW, you can purchase a Stant auto thermostat that will fit.

Jim Van said:

+1 . According to the gauge reading, on the highway it seems like the bike never warms up enough. But from past posts, they all act this way. Mine is the same. But the temp doesn't go up & down on the highway. BTW, you can purchase a Stant auto thermostat that will fit.

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As Jim stated, temp gauge should'nt be going up and down. That can be a sign of low coolant in the RADIATOR. Don't let full level in overflow tank fool ya'. THAT can very well mean that there is indeed a split in the overflow hose. The temp gauge WILL vary a bit with outside temp locations riding, BUT should stay constant in relationship to that.

OK, I'll jump in here to disagree somewhat. Considering that qman lives somewhere in Colorado, where the ambient air temperature could be coolish "out on the road" it would be quite normal to see a small fluctuation in the gauge as the thermostat opens and then closes again, once the cooler rad contents have entered the engine. I have witnessed this many times on my ST when the air is cool and the rad coolant has time to cool sufficiently between thermostat openings.

Other than checking your rad level, overflow tank level and the condition of that hose, I wouldn't give it a second thought.

It has been cool here in CO. So cool in fact that I feel I'm actually in my element.

My one buddy has his mesh summer riding jacket and he always has to put on a sweatshirt. I just thought it odd that the temp needle barely gets above the C when out on the road. I didn't worry too much cuz the bike runs perfeclty. If you see the range on my gauge as time from 11:00-1:00 the gauge maybe goes up to 11:20 and then falls back down to 11:03. It fluctuates like this over and over while we're cruising around up in the cool mountain air.

What time does y'all's gauge needle sit when out on the road?

Let's forget about the clock. Below is a pic of my gauge, a bit blurry, but you can see it. Engine is cold. Normally, on a warm-ish day out on the road, not in town, the needle will be sitting just slightly past the second thin white line on the cold side. On a hot day, in town, the needle will stand just PAST straight up, when the fan kicks in. On a cold or cool-ish day, the needle will get up to the same place as on a warm day, BUT it will drop to BELOW that second white line briefly, once the thermostat opens. It is opening and closing, as needed, on cold days.

So this tells me that normal operating temperature, not in stop and go traffic, has the thermo opening just past the second white line. If yours reacts similarly, it should be working as intended. If your needle never gets past the first big white line, then the thermo is stuck open, but you will still see the temperature rise in stop and go traffic.

Bush said:

OK, I'll jump in here to disagree somewhat. Considering that qman lives somewhere in Colorado, where the ambient air temperature could be coolish "out on the road" it would be quite normal to see a small fluctuation in the gauge as the thermostat opens and then closes again, once the cooler rad contents have entered the engine. I have witnessed this many times on my ST when the air is cool and the rad coolant has time to cool sufficiently between thermostat openings.

Other than checking your rad level, overflow tank level and the condition of that hose, I wouldn't give it a second thought.

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Don't let the 'Colorado' name fool ya'...... spring/summer, the Springs area gets really hot just as it does here in the G.Junction valley. It's 98 here today and I'm fairly sure their temps are close to that. Fall/winter weather WILL have that gauge just above the first mark, I grant you, but for the most part, it SHOULD react the same, runnin' between first mark and halfway out on the highway, depending on grade pulls, ect. Like I said, a slight varience in that range is ALL you should see, no matter how steep the 'pull' is. Anything above halfway and the lower first mark range...... bottom line is there's an issue that needs to be sorted out.