coolant overflow jug full

[Slow998]

I ran my Thundercat on Sunday on race gas tune. I made a pass on it, then let my buddy try it. When he got back, he just shut it off as he coasted to a stop. A few minutes later it was dripping antifreeze out of the overflow jug. I started the sled 3 times and let it idle for around 45 seconds to 1 minute each time and the engine temp went right back to 168 degrees, but the overflow jug is still full to the plug. Last night, I set the left ski on a 5 gallon pail, right ski on two 5 gallon pails and a 4x4 block on top of that, and left the back on the ground with it strapped down. Brought the sled up to temp and cracked the bolt on the turbo side and no antifreeze was present. Started the sled with the bolt out and let it idle until coolant came out of the hole and reinstalled the bolt. I did this probably 5 times last night, sometimes it would have coolant in the reservoir on the turbo side, sometimes it wouldn't. The overflow jug is still almost full to the top. Heat exchangers at the back of the tunnel are hot so it's circulating the antifreeze, but why would it just fill the overflow jug all of a sudden?

 

[acpantera]

Did you have the cooling system open recently?

 

[Slow998]

Did you have the cooling system open recently?

No. My sled has never been one to overheat nor have I had to add antifreeze to it.

 

[KnappAttack]

Sounds a bit like it boiled the heck out of the cooling system and introduced mega air to the system. I wonder if it pushed a head gasket out, or if the turbo just boiled crap out of the system. Hard to say in this case as it sounds like you set it on kill with a race gas tune, and the fact your buddy shut it down with absolutely zero turbo cool down time. Could be either one IMO.

I won't let people run my machines anymore after one incident many years ago. I learned my lesson on that one after having one friend total a machine and another friend do a bunch of damage to another. I also don't run trail sleds on the edge or set them on kill anymore either unless there's a lot of money on the line, save that for the race sleds in actual competition, funny how one gets wiser with age like that.

 

[jonlafon1]

Check your oil, does it appear like it has coolant in it? Is the oil level at proper level?

 

[Simplespeed]

Tough one, keep us posted on what you find please ….

 

[Slow998]

Check your oil, does it appear like it has coolant in it? Is the oil level at proper level?

Oil is at the proper level and the engine runs fine, no misfiring. I do have head studs and it didn't blow the plug out of the overflow jug like it was pressurized so I don't think it's a head gasket issue, but maybe that's just me hopeful thinking!!

 

[jonlafon1]

Oil is at the proper level and the engine runs fine, no misfiring. I do have head studs and it didn't blow the plug out of the overflow jug like it was pressurized so I don't think it's a head gasket issue, but maybe that's just me hopeful thinking!!

Good. Hope its just in need of bleeding the air out..

 

[Slow998]

Fingers crossed. I drove it across the lake back to the truck to grab my other sled and the temp gauge never went of 168... but it also didn't take any of the antifreeze out of the overflow jug

 

[sideshowBob]

I have found that the cooling system only pulls antifreeze out of the jug when it has been properly filled and bled before hand, a boil over throws the balance out of wack.
I think you are most likely dealing with a boil over.
Bleed the system and top it off properly, set proper level in coolant tank, warm the sled up and observe coolant level in tank, leave the sled out over night and see if the coolant level in tank has gone down slightly when cold from when it was fully warmed up. If it hasn't gone done somewhat you still have an issue.
Like KnappAttack I don't let anyone ride my sled and I don't ride anyone elses.

 

[Slow998]

Good news! I left my sled parked with the skis on 5 gallon pails and the track on the ground and when I got home tonight all the antifreeze in the overflow jug has been drawn back into the system.

 

[sxr70001]

It usually takes a complete cool down to pull liquid back in to the system. All the liquid has to contract