I have a polaris 500 ho (2001). Ive been reading lots of forums and have yet to find a solution. Please help. Mine is over heating with the light on and boiling coolant out of the resevor. also fan isnt coming on. heres what Ive tried.. hot wired the fan to run all the time just to check it. it works; quad will still over heat. i removed the thermostat and it still over heats with fan on all the time or off. replaced the radiator sensor it still overhears with fan on or off also with thermostat in or out.. also I take off the nut on the head to get any bubbles out each time. and ive tried a different radiator cap. the relay works fine, checked that to. with the cap off the radiator the coolant does move a small amount up and down when revved. the radiator is clean of dirt. the fan never comes on by itself, and if I unplug the wire to the sensor on the head by the thermostat my hot light just goes off, dont know if thats what is suppose to happen. Idk if thers anything else but im completely out of ideas. Any help I appreciate it. so Thanks in advance.

 

Welcome! Probably a good idea to pull the water pump cover and check the impeller out. If the impeller has gotten hot and melted(have had this happen) or slipping on the shaft, coolant won't be able to flow through the engine and will overheat. OPT

 

Ill give that a shot today. thanks

 

Plus forgot to mention,jack the atv up at the front with the tires off the ground and run the engine without the radiator cap to see if you have any trapped air pockets. Can take a while to do this on this model. Also make sure you have a fully charged good battery as the fan and sensor need a constant 12 volts to operate properly. OPT

 

Mine over heated due to a air lock in the system,had to fill rad as machine was running and it did a big burp. I also shook the ATV as I filled it slowly. (Manuals advice)

You know if you have a air lock if after it is warmed up the top rad hose is hard and hot but the bottom rad hose is soft and cool. When it working right both top and bottom hose should be firm and hot to the touch.

 

How high off the ground should the quad be jacked up? I tried to do this tonight and it seemed to have bubbles come out but when it warmed up it seemed to push a lot of coolant out of the top with the cap off. I dont know if that is normal or not. If I get time tomorrow I will try and see if the lines are actually hot or not. Thanks for the help.

 

My manual also says to raise the front end up 6" or more before filling the rad. Bubbling out of the rad filler hole is a good sign,it means air is escaping. Once the air is bleed out and the coolant is flowing properly then fill the coolant overflow bottle to the middle level.

 

Okay.. im still over heating and no fan on its own.. any suggestions? Im sure i got all the bubbles out n ive tried it at least 5 times of adding coolant different ways, lifted, adding while its running, shook it. the bottom hose did get hot and both were firm but if squeezed hard i could push um closed... I tried every way possible. and never had any luck.

 

If you're positive all air is removed,check that you have power to each side of the sealed 10 amp fan circuit breaker wires under the front panel. If not slice the pouch open and check for corrosion,bad connection. If the breaker is faulty most auto stores have em for about 5-6 bucks. Check the connectors going to the new radiator sensor also for good contact. OPT

 

okay i know it has been like a month since i last posted and im hoping someone may have some more help.. I have bleed the system 3 times to start over and i think i can say that i have gotten every single bubble out.. the fan will now come on sometimes but about 30 seconds later the over heat light comes on. also coolant will bubble out and is over heating in the resivor. there isnt any coolant in the oil and the oil is still fresh. im curious what else can be wrong?? can my head gasket be bad? even though no coolant gets in the oil? if i can spin my propeller in the water pump but it has a lot of resistance is that normal? if i park on an incline with the front up my fan will run at least twice before the coolent starts to fill the resivor which i just shut down as soon as i can feel it and its realy hot ( boiling) .. thanks again for all the help everyone. ive never been stumped like this before. Polaris 1 - me 0..lol