Help! Overheating or what???

[The Goat]

So I have an '02 Edge 800 and the other day it started running a little funny, but the temp light never came on. The next day it ran just fine for about 20 minutes in the powder and then it started acting up again. And then the temp light started lighting up unless I was on the throttle. It got worse and worse as I limped it back to the trailer. It wasn't melting snow on the tunnel and rear cooler like it should, so I assumed it was a broken pump belt. It sat in the trailer all weekend and when I started it up, the temp light immediately came on (like .05 seconds after it started!). It sputtered off the trailer and into the shop. So I tore into it.

Water pump belt.....Good.

Thermostat.......Good. I checked it in the sink with hot water and it opens up just fine.

Water pump impeller........Good. I thought maybe it was spinning on the shaft, but I put quite a bit of pressure and it won't budge, so I'm pretty sure that's not the problem.

Checked the coolant flow and it's flowing, but it just doesn't seem like a whole lot. At a high idle, how much should that thing be pumping???

And I have no idea why the temp light would come on right at startup. Any ideas???

Thanks for any help!

 

[Ryanlilly]

My guess would be a bad temp sensor. Pick up a new one and give it a shot. About $ 30.

Good luck

 

[boxster7614]

X2 sounds just like temp sensor

 

[The Goat]

But that would only explain the temp light, wouldn't it? Its not just that the light is on, it runs like crap too. And its not melting snow on the heat exchangers.

 

[boxster7614]

Don't know about the exchangers, are you sure they aren't getting warm? Probably not melting snow because the sled isn't getting hot......its working properly.


The Temp light is controlled by the CDI using water temperature input from water temp sensor, throttle position input (TPS) and RMP input. with the Temp sensor as the temp increases the resistance decreases. Each input has thresholds programmed into the CDI for when to illuminate the Temp light acording to coolant temp, TPS and RMP.
For example, the Temp light will come on at idle and coolant temp of 110 degrees C, timming retard initiates at 176 degrees and a TPS over 80-100%. For more severe conditions, the engine fail-safe is turned on at a high TPS input and high temps.
So the resistor changes its threashold as when to come on in acordance with your throttle position. the timming is retarded when it gets to high and this is why your sled runs like crap, its stuck in limp mode. Most of the time this is because of a failng temp sensor. sometimes they fail completley and other times they start to get progresivley "out of range" thus becoming more sensive to the throttle position and send sled into limp mode or sometimes just severly retard timming and not iluminate the light. If your temp light is comming on when the sled is first started and cold then its definitley a temp sensor that has failed.

 

[The Goat]

Thanks Boxster. That makes a lot more sense now that you explain it like that. I'll pick a sensor up after work and see if that fixes it. Is it bad to just bypass the resistor by the temp sensor? Could that fix the problem without causing other issues?

Thanks!

 

[boxster7614]

If you want to bypass it you have to put a resistor in, SLP sells a kit that has a resistor. otherwise if you just unplug it or wire it together the sled will go into limp mode. The Temp sensors tend to fail after a few years, but in my opinion I think its a good protection circut to have in the sled for when you really do over heat, which will happen.....either going down an icy trail and you don't have enough snow for the coolers, or when your water pump belt breaks. Change it out and you shouldn't have to think about if for a few more years. Some guys will carry a spare in the back of their sleds, you don't have to thread it into the head for it to work, it just needs to be plugged in. So if you're out in the back country you can just plug it in an go on your way.

 

[The Goat]

Good to know. Thanks for the info. Man, it's crazy how much people know about my sled on these forums! I'll let you now how it goes when I get it thrown back together tonight or tomorrow.

 

[The Goat]

Seems to have worked! I've only ran it in the shop, but it turned the temp light right off and seems to run just fine. Heading up the hill after work today to see how she runs in the snow.

Thanks for the help guys!

 

[Ryanlilly]

Glad to hear you got it fixed.

 

[rmkboxer]

Thanks Boxster. That makes a lot more sense now that you explain it like that. I'll pick a sensor up after work and see if that fixes it. Is it bad to just bypass the resistor by the temp sensor? Could that fix the problem without causing other issues?

Thanks!

I carried a test one in my sled when I had it, I was riding with a guy last year and he was overheating and decided to just plug in the resistor and ride it w/o checking anything else or asking someone who knows. you will be gambling with your motor, pay $30 for a sensor or $1000 plus for a motor rebuild. I honestly recommend carrying the resistor or a extra temp sensor