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2011 500 Cooling System Question

2088 Views 19 Replies 5 Participants Last post by  deanot
This past summer I did a daytrip (around 60 miles) on the railbed east of me. Air temp was probably 75-80*. I was probably riding @ around 35 mph. I have a temp' gauge & noticed that the fan cycled on & off regularly @ the typical "points" on the gauge (Same as when I'm riding @ low speeds in the bush). I thought the intervals between the fan coming on would've increased.

I would've thought that yes, running faster would create more heat, but the increased airflow thru the rad would cool the coolant quicker. Any thoughts? Is the rad not large enough to take advantage of the increased airflow @ speed?

Next year I'll make sure the fins are clear (it may have been a while since they had been cleaned). I don't go mud bogging w/ the Ranger, but dirt does accumulate.
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ive often pondered this too man kris, a lot of the other buggies we ride with rarely cycle the fans unless its really hot or they're working them pretty good. Polaris's seem to alsways kick on and off. Most finger point at the "lean state" that they're set at from the factory. I point at that as well. In the summer my fan cycles just as much as prolly yours and a majority of everyone elses does.

ive often thought about making "louvers" to direct the air into it more, however that would more than likely also deflect DEBRIS into it as well. Another thing that detered me from doing this is the idea that the way the winches mount is RIGHT infront of them..that kinda SUCKS!
Another thing that detered me from doing this is the idea that the way the winches mount is RIGHT infront of them..that kinda SUCKS!
Actually that gives me an idea. The 1 railbed ride is an "out & back". My winch is on a multi mount. If I can remember, I'll remove the winch @ the destination (turnaround point) & head home. I'll see if that makes any difference. I did notice 2 vertical tabs (about 2" x 2") on the EMP mounting brkt. I removed them since I wasn't using them & all I could see them doing was disrupting airflow to the rad.

I saw your Water Wetter post. That's what got me thinking of my situation. I'm using it as well in my Ranger since the ride in question. I haven't been on any "high speed" rides since though.
My highspeed is like 30mph..lol thats down the road. i aint out to break speed records. haha. Yah my water wetter question has me thinking..but then Neal said about POSSIBLY my thermostat, so i ordered one for the hell of it. Imma do some testing to figure out whats going on.
An update on the cooling. I did 89 miles today on the railbed and the ambient temp was 48*. Speed was about the same as the previous ride. The fan hardly came on today. A lot of the time the temp' gauge was showing 160 or just slightly higher. If I stopped & turned off the Ranger for a few minutes then restarted, the gauge would show 200 the fan would then come on. After a few minutes of travelling the gauge would drop back down & the fan would shut off.

I'm thinking ambient temperature has a bearing on cooling system performance.
I do remember my former 800 cycled the fan frequently and now under the same riding conditions my 570 cycles rarely. I think Wagz is right, the lean tuning of these machines make them hot and likely varies slightly per machine.
My 2014 800 is constantly on and off, even in the dead of winter it cycles more than I feel it should.
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My 2014 800 is constantly on and off, even in the dead of winter it cycles more than I feel it should.
ditto! odd yes!?
I haven't noticed the cooling cycles in Nov' or Dec' (the only cold months it sees service). Yes it is cold, but I'm usually just putt putting around the woodlot, so there wouldn't be much airflow thru the rad @ these speeds. I would think the fan would cycle more often under these conditions.

I'd like to hear any comments w/ folks that own the 500 motor.
You might try google options, but someone here or elsewhere had put in an override button which allowed them to turn on the fan at will, might be a good option and considering it myself, especially at low speeds.
I put one on my 400 as well as a temp gauge. when its hot I let the fan run all the time. If its cool I'll let it cycle. The temp at which the fan comes on is hotter than the normal operating temp. When the fan comes on its a little too hot and the fan has to run a lot to bring the temp back down. If I let the fan run constanly the engine runs a little cooler than normal but its consistant. I had too tow a Brute Force 650 back to camp last year with 2 passengers on it and with the fan running non stop the engine did not get any hotter than it normaly does just riding.
I put one on my 400 as well as a temp gauge. when its hot I let the fan run all the time. If its cool I'll let it cycle. The temp at which the fan comes on is hotter than the normal operating temp. When the fan comes on its a little too hot and the fan has to run a lot to bring the temp back down. If I let the fan run constanly the engine runs a little cooler than normal but its consistant. I had too tow a Brute Force 650 back to camp last year with 2 passengers on it and with the fan running non stop the engine did not get any hotter than it normaly does just riding.
Can you post a picture of the set up, thanks in advance.
You might try google options, but someone here or elsewhere had put in an override button which allowed them to turn on the fan at will, might be a good option and considering it myself, especially at low speeds.
I didn't think that's neccessary. W/ the slow speeds the Ranger sees when working the woodlot & watching the temp' gauge, the cycling seems normal. In the OP I just thought it strange that the cycling seemed the same even w/ the increased airflow thru the rad during higher speed riding.
ditto! odd yes!?
Odd is a mild way of putting it, yes... lol

I haven't noticed the cooling cycles in Nov' or Dec' (the only . Yes it is cold, but I'm usually just putt putting around the woodlot, so there wouldn't be much airflow thru the rad @ these speeds. I would think the fan would cycle more often under these conditions.

I'd like to hear any comments w/ folks that own the 500 motor.
I think some of these Rangers run hotter than others, it is like the hot seat problem that appears with some and not others. I find it weird that some run LEAN and some do not run as lean, I mean, these things must be built to some specifications.

Makes me wonder about something. We know some of these are made in Mexico, do the ones that come out of mexico run leaner, or richer? I wonder if there is some rhyme or reason to it all.

Thoughts on this?
I would think that the calibration would be checked before the Ranger left the line regardless of where it is built. Are there any EPA standards that apply to off road vehicles? I know that snowmobiles have EPA standards to comply w/ like on road motor vehicles.
I would also of thought the same, but depending on climate, fuel type and so on. Maybe these calibrations don't match as we would hope?, I know mine was made in Mexico, the rest are made somewhere else, can't remember where!

Maybe a poll is needed, to find out if there is some tie to location..... hmmm
I would also of thought the same, but depending on climate, fuel type and so on. Maybe these calibrations don't match as we would hope?
You might be on to something there. I may be a bit off w/ my theory, but please chime in to correct me.

[h=5]Open Loop[/h]When the engine is first started the system goes into open loop operation. In open loop, the ECM calculates the Air/Fuel ratio based on inputs from the coolant and MAF sensors. The system remains in open-loop until the following three conditions are met:

  • Coolant temperature above 105°F.
  • Oxygen sensor has varying output voltage (indicating it is hot enough to operate properly).
  • A specific amount of time (preprogrammed into the MEM-CAL) has elapsed.

[h=5]Closed Loop[/h]When all of the above conditions are met, the system goes into closed loop operation. In this mode, the ECM calculates the Air/Fuel ratio based, mainly, on input from the oxygen sensor and maintains the Air/Fuel ratio at the desired 14.7 to 1.
Limp Mode or Fuel Back-up Mode
In this mode, the system operates on a fuel back-up logic, programmed into the CAL-PAK portion of the MEM-CAL, to control the engine if the ECM or other specific sensors fail. As indicated by the limp-mode designation, engine performance is substantially less than it should be.
Notwithstanding the claims of the manufacturers of these harnesses, operating in either of these modes may drastically affect the efficiency and fuel mileage of the system. For a TPI, or any other similar electronically controlled system, to function in the closed loop mode, there MUST be an oxygen sensor in the system.
When Polaris intro'd the RXL sleds in the 90s w/ fuel injection, I'm pretty sure there was no O2 sensor & the fuel "map" was just set up on a dyno depending on throttle position @ different RPMs. Not sure what if any outside "inputs" the ECM received.

I'm sure there are folks on here that know the ins & outs of the FI system & can confirm or deny my theory.
It would be interesting to see, Mexico for instance in most areas would be hot and dry, if these specs was blown into the program... well thats one thing. But what if somewhere that was cooler and more humid, and these parameters was blown into the ecu.

I maybe barking up the wrong tree, but something has to different from the ones that run hot, and the ones that run "Normal", if there is such a thing.

I was thinking of buying an add on fuel managment system, but I don't want to fork out $500 plus to fix something that should never of been released like this. Mine runs really hot, 0°F outside and my fan still cycles like its 80°F outside... lol.
It pays to read the manual. Yesterday I noticed the coolant level was low (to my eyes) in the overflow bottle. I topped it up to the upper line. I was into a couple of hunting camps visiting friends later in the day. This morning I looked @ the overflow & I could see coolant had burped out the vent hole.

I looked in the service manual & the coolant level is to be checked when the engine is hot (throwing my hands up). This is the 1st vehicle that I've had that this was the case. Does anyone know of another vehicle that is set up like this? Any of my vehicles & snowmobiles specify a level when the coolant is cold. It's a lot easier to add coolant to a cold vehicle than a hot 1.

(The coolant level was OK after I let it warm up. About 1/2 way between MIN & MAX).
I noticed my bottle was empty also, had some coolant in the pipe, but that was it. I can imagine when the engine is hot, the expansion of water should, should take it to the full level.
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