Thermostat or Air Lock

[hlmrx1]

The asphalt skis are gone and the snow skis are back, quick disconnects are off, coolant topped off and bled, well I figure anyway. Go for a short ride, come back and top off the coolant reservoir and figure she’s good to go. Kept my eye on the temperature gauge, and it’s running around 160f and it’s fricken cold outside, -25 to –30c. Everything is good for the first 20 or 40kms, even stopped in between to warm up and it was ok to get to our next stop. This time we stopped a little longer, went to head home and now I’m not paying that close attention to my temp gauge and the sled shuts down about 1.5 miles into the ride. Noticed the temp gauge was way up there, so I let it cool down then start it up and the temperature drops back down to around 180 then climbs to 200 then starts to really climb fast, so I shut it down. Checked the heat exchangers and they are ice cold. Decide to tow back to our last stop and bring it inside and see if the system needs bleeding. Added very little coolant and started it up but it doesn’t seem to be flowing.

Now I’ve suspected that my thermostat stuck before but seemed to clear up right away. This could be an air lock as I’ve just finished the asphalt to snow conversion. I’ve searched the forums here and did find one mention by Mr. Sled that he had heard of reports of thermostats sticking on these sleds, not sure if it’s only the 03’s or other years. Has anyone else experienced problems with the thermostats staying stuck closed?

I think I’ll pick up a new thermostat anyway just to be on the safe side.

 

[black john]

thermostat

i have seen a stat stik before on an rx 1 . affter all we have all seen stat,s stick in car,s and truck,s at one time . just pull the bleed screw at the back of the sled and check for air 1 st if that,s not it there you go .

 

[Len Todd]

In the field, you can always take the thermostat out and run without it. But, I would bet on air in the system. Get the rear end up in the air a bit and blead the air out of the thing.

 

[hlmrx1]

I haven't had a chance to look at it yet, but would an air lock have shown up in the first few miles????

 

[LazyBastard]

Not necessarily. Sometimes the air has to work into a place where it can cause the most trouble.

 

[hlmrx1]

Well checked it out tonight, jacked up the rear end, loosed off the bleed nut and ran it up to over 165f. It didn't seem to need any antifreeze, I just ran it until I had antifreeze dripping out the back bleed nut. Heat exchangers were hot so the antifreeze was running through them. Took it out for a couple of miles and no problems. Could a very small amount of air cause an airlock, I mean a small enough amount that would be unnoticeable?

 

[Red2003]

This being a drag sled, do you think you might have a bad head gasket? The symptoms sure sound a lot like it to me.

 

[hlmrx1]

Doubt it, but can't rule that out yet. I don’t seem to be losing antifreeze. I’ll have to get it out and see how it runs, but not go to far yet. I’ll be picking up a thermostat and probably change that out as I suspect that it’s stays stuck closed sometimes.

 

[Red2003]

If the theromostat doesn't fix it, I'd bet its the head gasket. Sounds like you got compression leaking into the water galleries and blocking the coolant flow. If this was the case, you probably wouldn't see a loss in coolant. Best of luck.

 

[hlmrx1]

Red2003 you had me worried!!!!! Well I bled the line last week, I didn't really see any air bubles or anything like that, didn't have to add antifreeze. Went for a nice long ride yesterday and the temperature guage stayed anywhere between 155 to 165f, so everything is good to go. I think I'll pick up a new thermostat anyways as some people here seem to have had some problems with these sticking shut. Thanks.

 

[Red2003]

Red2003 you had me worried!!!!! Well I bled the line last week, I didn't really see any air bubles or anything like that, didn't have to add antifreeze. Went for a nice long ride yesterday and the temperature guage stayed anywhere between 155 to 165f, so everything is good to go. I think I'll pick up a new thermostat anyways as some people here seem to have had some problems with these sticking shut. Thanks.

That's great news!!!