ok... I have a 2000 polaris Sportsman RSE. I just recently got it. It is overheating after a very short amount of time. The overheating light does not come on, but you can hear that it is too hot! The fan is not comming on. Where should I start to troublshoot this?

How could I check the water pump?? I have read how to check the temp sensor and the fan. I want to be able and sit down and do all of my checks once. That is why I am asking before I do the other things.

I know I need to check the:
1. fan
2. clogged radiator inside and out
3. temp sensor
4. look for kinks, etc.

what else should i do??

thanks in advance!

 

I also forgot to mention... i do not notice any overflow of any kind from anywhere on the bike....

 

I've got the same machine and the overflow is behind the left hand side panel (from driver's position) in front of the EBS cover. Mine overheated from lack of coolant, my overflow was empty. I filled the coolant when the atv was warmed up and had not had a problem in the last 6 months. Not to be a smart guy but how can you tell the engine was too hot by listening to it? The last ride I went on, I spent a lot of time in the mud (2 hours), and I didn't hear my fan kick on at all, But I finally did notice it on the ride home. Lastly, I clean my fan and radiator after every ride.

Thanks,

Jim

 

If fan is not coming on then disconnect fan and you can check with 12 volts direct to see if fan motor is ok, if fan ok then would suspect radiator sensor as faulty.Wouldnt hurt to check radiator for mud and dirt while you are at it. Radiator should be even temp to touch all around with no cold spots! You should see coolant circulating to eliminate w/p impeller damage or slipping on shaft. Disconnect temp sender on side of cylinder and hot light and fan should come on also.

 

I had a friend tell me that if you have too much coolant that it will overheat as well. Don't know if it is true or not but, it is the best I can do.

 

If the ATV over heats water will boil over out the overflow bottle. There are two sensors the one on the rad tell the fan to come on or off and the one on the side of the motor tell the over heat light to come on,the chance of both failing at the same time is rare.

Like mentioned unplug fan (Remove front rack) and put 12v direct to the fan leads to see if the fan is working first.

 

Lots of good responses already.

I, too, would ask what makes you think it's overheating? First real sign of overheating, idiot lights aside, is the overflow peeing out the top. If the overflow is normal - coolant in between the min and max lines, I'm not clear on why you think it's overheating.?.?

The fan can be checked by applying 12v to the connector. If the fan is bad, you can buy a direct replacement from SPAL for 1/3'rd of what Polaris charges. Same fan.

Rough check the water pump by taking the radiator cap off (when cold), start the bike, get it up to temp. Once the thermostat opens, you should be able to see the coolant flowing inside, across the radiator cap opening. Should flow faster with engine RPMs.

Test thermostat by pulling it out, and placing in a pot of hot/boiling water.

Sensors are a little harder to test. The fan switch, which is located in the bottom of the radiator, can be 'tested' by elimination. If you tested the fan and its ok, yet the quad overheats without kicking on the fan, it's probable that the fan switch is bad. BTW - 2000 SP500's are known for failing fan switches. I've had to replace mine.

I've never tested the overheat light sensor, not sure on that one.

Again, I would make sure it's really overheating before doing all this work.

 

Once mine fan would not come on due to the connnection between fan and rad sensor was very dirty, I cleaned it up and it worked after that. its the connection with the brown and orange/black wire.

The rad sensor also has a 10a circuit breaker on its red/white wire, if that could ever be the problem.

 

the hot lamp can be tested by unpluging the lead from the sensor located on the head/jug and grounding it out to make the lamp come on.

the sensor can be tested in a pan of hot water-with salt or antifreeze--needs to get to 220 degrees F. the sensor is normaly open from the lead terminal to the threads. At about 220 degrees it will close the contacts and ground the circuit to light the lamp.


the fan switch is a normaly OPEN switch that will close at 180-190 degrees F--different machines and years have different values--none the less the fan comes on LONG before the HOT LAMP.


one more thing to check is that the water is indeed moving in the radiator cap areaa after warm up--past posts points at water pump only--

I would add the thermostat if no water movment is found.

 

Hey guys, I don't know if the original started of this thread reached a conclusion or not, but I was hoping maybe some of you can give some insight to me as well.

I have the same problem with my 2000 sportsman 500 overheating. It started with the light coming on, which was after about an hour of moderate riding. I was towed home because I couldn't see inside the coolant reservoir and thought I was just out of coolant. So I picked up antifreeze at the local atv shop and came home to fill it up... It was fine.

So, I checked the fan by putting 12V to it and it kicked right on. I let the quad idle for about 15-20 minutes and antifreeze started squirting out of the pinhole on the coolant reservoir cap. I don't know where the sensors are/what they look like or how to check them. I'm guessing the black box with 4 wires coming out of it is one of the sensors. How do I check if that's functioning properly?

Also, unrelated to that problem, I had a right wheel bearing installed because from that side I was hearing loud clicks most of the time and all of the time when I would turn hard to the right. The people who installed it didn't put oil in the hub, just grease. It started clicking again after 1 or 2 rides from the installation. I called them up and they said the nut holding them in probably just needed to be tightened a little more. I unscrew the rubber cover and that's when I noticed there was no oil. I tightened it up a little bit and then retried, still clicking. Then I unscrewed the left side just to check how tight the nut should be, and that's where I found out the right side should have had oil, because the left side was full. Now, is it possible I just need oil put into the right hub or did not having that ruin the new bearing and I need to replace it again?

Anyway, even if no one is able to answer my questions I still learned a bunch just from the little I read, so I appreciate everyone's input.

Thank you!