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2001 Magnum 500 Overheating

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Old 03-18-2017, 09:47 AM
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Default 2001 Magnum 500 Overheating

New to this site. I'm hoping to find one of the pros on here to help me get my problem fixed.
I checked the sensor in rad and ended up buying new one. Both sensors actually work so bought one for nothing and still overheating.
Checked thermostat in a container heating up water and it opens and closes.
Checked water pump and it seems ok,started motor for a second and watched impeller spin.
Tried jacking up front while putting antifreeze slowly into rad to burb system and opened the little bleeder on water pump.
Still always overheats
Last night I took rad off thinking it's blocked,from what I can see inside it looks good,clean. Is there a way to check it with water.
What should I do next, I'm at a standstill here and need help.
 
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Old 03-18-2017, 11:24 AM
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It's not just what's inside the radiator but the area mainly behind the fan shroud. Radiators need to be clean front and rear on the older models as they were mounted lower and caught everything.Also if working right the fan should kick on way before the hot light does. Sometimes takes several minute to purge all the air out of the system and allow the fan to cycle on and off 3 or more times.Then you should be able to top of the radiator and over flow bottle. You ca do an amperage test on the fan motor also. If it takes more than 7 amps to kick on,the fan motor may be getting weak.
 
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Old 03-18-2017, 01:07 PM
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Originally Posted by old polaris tech
It's not just what's inside the radiator but the area mainly behind the fan shroud. Radiators need to be clean front and rear on the older models as they were mounted lower and caught everything.Also if working right the fan should kick on way before the hot light does. Sometimes takes several minute to purge all the air out of the system and allow the fan to cycle on and off 3 or more times.Then you should be able to top of the radiator and over flow bottle. You ca do an amperage test on the fan motor also. If it takes more than 7 amps to kick on,the fan motor may be getting weak.
Thanks for the quick reply. Rad is clean front and back I clean it all the time,learned that quick how clogged up with stuff it can get. Today i ran water through the rad to make sure it's not clogged up.......clean. Ran it again with thermostat removed and tried squeezing all the hoses to purge air out and still over heated after a few minutes. The bottom hose on rad never gets hot as if it's not circulating properly, thermostat housing is very hot to touch pump housing hot but not like thermostat. Like I said impeller looks in good shape but did notice some scoring inside pump housing.
 
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Old 03-18-2017, 01:39 PM
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I'd recheck the impeller to make sure it's tight and pressure test the cooling system.
 
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Old 03-18-2017, 02:19 PM
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Originally Posted by old polaris tech
I'd recheck the impeller to make sure it's tight and pressure test the cooling system.
Tried holding impeller with a piece of wood while buddy bumped the motor over with no spark plug, impeller chewed up wood. Would it be wise to put a stainless lockwasher under the nut, just in case. Will be borrowing a pressure tester and let you know the results. Been reading a lot of people have had this same problem, seems like airlock is a big problem. Is there no easy way to get the air out other than flipping the machine head over heels.
 
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Old 03-18-2017, 02:25 PM
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Just takes time. With the front end jacked up,I've spent as long as 45 minute to an hour purging air pockets out of some machines.Main thing is the fan needs to kick on before the hot light does. Plus you have to leave the radiator cap off at all times during this process.
 
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Old 03-18-2017, 06:54 PM
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Originally Posted by old polaris tech
Just takes time. With the front end jacked up,I've spent as long as 45 minute to an hour purging air pockets out of some machines.Main thing is the fan needs to kick on before the hot light does. Plus you have to leave the radiator cap off at all times during this process.
Thanks for all your help, I borrowed a rad pressure tester tried it and it held good. Then I got an idea, fill the rad as much as I can then hook up pressure tester and pump it up. I did this a few times adding more water each time and opening thermostat housing to let air out until one time water came out. Then I started it with the fan on bipass running steady until I seen water starting to circulate and steaming. Plugged fan back in ran it for quite awhile letting fan kick on 3-4 times and it's perfect. Wish I knew this before buying a new sensor and taking the front end apart to get rad out. I noticed the rad cap doesn't really lock on like a car,it kind of just sits there but doesn't leak.
Is it ok to remove thermostat and run it without one for better circulation.
 
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Old 03-19-2017, 08:09 AM
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I'd install the thermostat. All Polaris machines should have a bleed screw on the thermostat housing like the Ranger 700 and 800 have. Would make purging air a lot easier.
 
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Old 03-19-2017, 09:45 AM
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What are the effects of having or not having a thermostat installed
My machine doesn't have a bleed screw on thermostat but does on pump housing.
 
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Old 03-19-2017, 11:33 AM
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The thermostat is there to control the flow of the water. With out the thermostat the coolant will move too fast and not take the engine heat away with it. Plus the coolant needs to stay in the radiator to cool down and not just race through. Fan sensor may not trigger in time before the hot light does. Use the thermostat,good 50/50or 60/40 coolant.
 



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