[PolarisGuy85]

Was out for a ride on my xlt and thought I could hear a hissing sound under the hood I checked it out and saw that coolant had been coming out the cap on the bottle this happened at a high rmp around 8000 could this be the o-rings under the head cover (its a monoblock) if so how many are there and whats the best way to go about it any help would be great thanks

 

[burnoutking]

Are you saying it was overheating or are you thinking a cylinder leak was pressurizing the coolant system.

Check simple stuff, like thermostat first, then pull the head and check the o-rings. Maybe you just weren't getting enough snow on the coolers. Was it a warm day also?

Doesn't really sound like 0-rings to me. But who knows. I would think you would have antifreeze leaking out the head and even in the exhaust if the 0-rings were that bad.

 

[deezy]

If its coming out of the bottle cap then I'd say the plastic that the bottle cap closes onto isnt sealed properly anymore, it's happened to me before, new bottle and I was fine. Could be overheating too..

 

[PolarisGuy85]

Well we've got lots of sno and it was around -12 and it wasnt just leaking out the top it was spraying out the vent hole on the bottle... the reason I assume it's the o-rings is it only does this at a high rpm and have heard about them getting worn and leaking at high rpm's

 

[burnoutking]

Definitely not expensive or hard to change, so it wouldn't hurt to check them.

 

[PolarisGuy85]

alright thanks figured I'd check and see if anyone one else has had this issue first

 

[PolarisGuy85]

Now that I've decided to pull my head cover off does anyone know the torque for the bolts and any tricks to avoid an air lock?

 

[twh7mm]

I had the same thing happen on a 97 600 XC with the monoblock it turned out to be a head gasket. if you have a head gasket leaking you can tell by taking the cap off of the overflow bottle and putting a small balloon in place of the cap then start it if the baloon fills up then you probably have a bad head gasket

 

[69CRUZR]

I have the same exact issue going on with my 98 XC600 twin right now. But, I just had to replace a cooler line from the rear of the brake caliper down to the tunnel cooler. What the problem is with mine is that Im having problems getting the air bled out of the system, so when it gets warm it flows out the overflow. when I lift the lever on the thermostat housing when its warm (not hot) I hear it gurgle througout the whole system and sometimes get an air bubble or two out, but havent gotten it completely bled yet. I have heard theres a specific way to bleed the cooling system first, and I would surely try that before tearing your heads off.... Thats what Im gunna do.

 

[TwinsofMLB]

I have heard theres a specific way to bleed the cooling system first

Elevate the front end higher than the rear exchangers, take off the cap and let it idle for a few minutes.

 

[PolarisGuy85]

Thanks for the replies guys I just plan on doing those o-rings for now and see if that cures my problem and I'm gonna pray its not a head gasket not the right time of year for that