2002 Sportsman 500 ho - overheating

[polariseddie]

Hello everyone.

I have an overheating problem. I started by replacing the temp sensor in the bottom of the radiator. No luck. I brought it to the dealer and $450 later I am still overheating. they Replaced the thermostat, cap, filler neck, and water pump gasket, and cleaned and flushed the radiator. The radiator has been completely removed and cleaned. all hoses have been removed and flushed.

What I noticed was the machine would rock crawl and play in the mud all day long, but once I opened it up to 30 mph it would overheat instantly. I research this after giving up on the dealer and found that a spark plug could cause it. I then replaced the plug and filled everything and went for a ride. I buzzed around at 40 mph for 1 hour with no problems. Once I started up a trail with some rugged terrain it again overheated on me. So now the problem seems to be the slower strenuous trips.

I am flat out of ideas. Any possible help would greatly be appreciated.

Eddie

[MrBill]

How did the spark plug look? Very Tan. Running to lean maybe.
Does your fan seem to be running at full speed?
Coolant mix right? To much coolant vs water mix will change the heat transfer of the cooling system.
The shop said they cleaned the radiator.(was this the inside?) You may want to try cleaning it your self the outside, no pressure washer just garden hose in the front and in the back and repeat. You can get mud way up in the fins and it still can look clean. With the motor cool flush out the fins.
Oh yea Welcome polariseddie

[Mr. Miyagi]

First off, I'd get my $450. dollars back......

[Ken]

Chadd heard of this one before?


No....not the Dealer ripping off for $450 part....the Overheating part.

[Chadd]

Does the fan kick on? let it idle and get hot and see if the fan comes on... like terry said get your $450 back first.. I have never changed a any of the parts listed above. Sounds like the sending unit for the fan is bad. You can also try wiring the fan directly to the battery to make sure the fan works.

[polariseddie]

Thanks for all the responses.

The fan did come on during my first test run. So I decided to take it on a longer run. I ran for an hour with no problems. Then it overheated, and I noticed the fan was not running.

I have been dealing with this for just about a year now. I have tried hard wiring the fan, same result. I have cleaned the radiator, inside and out thoroughly. The Fluids have all been checked and are on par.

thru research and just plain brainstorming, we have come up with 2 possiblities. As far as I can recall, the day it started, I had just chewed up a belt driving thru 12" of fresh snow. I changed it on the trail and then 10 minutes later it overheated on me. So I am thinking it was a defective belt. My repair manual says that brake and transmission drag can cause overheating.

My cousin seems to think the supply hose is soft and collasping causing no flow. this would explain the fan not coming on (no hot water getting to the fan sensor, which has been tested and replaced).

Do you guys think either of these hold water? Thanks again.

Eddie

[MrBill]

My cousin seems to think the supply hose is soft and collasping causing no flow. this would explain the fan not coming on (no hot water getting to the fan sensor, which has been tested and replaced).
Eddie

Haven't seen a hose collapse but, you my want to find a spring that will fit over the hose and see if this stops it.

[Chadd]

Water in your oil? Blown head gasket?

[Joey2]

Hey Polariseddie,

I see that you found the site.

I feel confident that someone here will figure this out, these guys are good. Better than the other site I think.