'04 Summit 800HO- Overheating-Please Help

[Ol' Skool]

Buddies summit is overheating quick. Lots of snow and not running overly hard. Temp light comes on quick, cool down, fires back up. Heats right back up. Boiled over once. Lots of antifreeze. Right plugs. Lots of snow. Any Ideas? Thanks!

 

[DRD]

Check thermostat, they have been known to fail.

 

[Ol' Skool]

If it is the thermostat, how would the coolers be hot too?

 

[slededjr]

Air locked? Do any work to it recently? Could be T-Stat, they are suppose to stick open when they fail. So basically the coolant will not stay in the heat exchanger long enough to cool down. If there was no work done to it lately to cause air lock, change the T-Stat and you dhould be good.

 

[Ol' Skool]

Recent rebuild, and overheating ever since. Will check the thermostat and try again.

 

[DRD]

If it is the thermostat, how would the coolers be hot too?

How can the coolers be too hot if you are getting lot's of snow on them? Stats often fail closed, engine will overheat but you will see minimal heat out in the exchangers.

 

[cdnemsguy]

Stat would be my first guess too, but other things to look at is air lock, where you would have to lift the front of the sled high in the air to get rid of, or the water pump is not doing its thing. Should be able to check the heat on both sides of the t-stat to see if there is a huge different and go from there.

 

[SHREK1]

bet its an air lock , lift front of sled way way up to get rid of

 

[kjb]

Air lock.

 

[Ol' Skool]

Buddies going to pick up a new thermostat tomorrow, throw it in, and try bleeding it with the skis up on blocks. Hopefully that cures this thing.

 

[nielsy]

when rebuilt was cavity behind oilpump filled with oil ? if not it could be the plastic gear that failed then there is no circulation and your oilpump will not pump

 

[kbrunlees]

Had the same problem with my Can am quad, doing exactly the same thing. I am suspecting your waterpump has failed. On mine the driven gear simply broke. Don't know why, all I know is that is a royal PIA to get at. If you remove the thermostat does it still over heat? You can also tell by leaving the thermostat out and open and start your sled if the water goes every where the pump is working if it just sits there, scratch one waterpump.( and yes I know the quad is 4 stroke and the sled is 2, but the water still has to move right?)

 

[wangdoo800]

Has the head been removed? If so it sounds like a pinched o-ring on the cylinder head.

 

[Summiteer]

Has the snow flap been removed? You'd think hot exchangers would indicate water is moving....

 

[Ol' Skool]

So new thermostat installed and bleed with skis up in the air. Still overheating. Took off the head, new O-rings- old one didnt appear to be pinched. Still overheating. Tons of snow hitting the coolers, tunnel coolers are hot. Doesnt seem to be getting back to the front cooler. Maybe a blockage?

 

[SHREK1]

stand that thing on its tail , air lock can be hard to get out, higher the better