Need help with coolant issues

[mncruiser]

For a while now I have noticed a coolant smell but can never find any evidence of leakage. I pulled the side cover and the overflow tank was completely empty and refilled it. Some times after a ride you could hear what sounded like a boiling noise and I suspected it was coming from the overflow but it quickly stopped so I didn't worry about it. About 2 weeks later I am still smelling the coolant and was given advice to pull the tank and look at all the hoses under there. Today I did just that but found nothing. I tightened all the hoses but none were really loose. While tank was off, I changed out the coolant and again the overflow tank was bone dry. Today I took the bike out for a ride and again smelled coolant. Back to the garage and pulled the side cover and it was empty again! Refilled and started bike up and of course, the level in the tank began to rise and eventually overflowed a little so I siphoned some back out. (Getting long, sorry) Fire the bike up again and coolant returns but doesn't overflow, fan runs so I shut it down after it cycled and the coolant tank goes nuts, it begins to boil (See link below for a short video on this)violently. I now know this is what I've been hearing. After the boiling settles down, all the coolant is sucked dry from the overflow tank.

What is going on? I was going to run it over to the dealer but he is the only KAW dealer near me and he knows it. not a fun place to visit!
Boiling video http://picasaweb.google.com/Onmylast...93198103132402

[bobzinger]

Is that boiling or just bubbling? The only time I ever experienced anything like this I had a blown intake gasket on a truck. Check your oil and make sure it doesn't look milky. If it is then coolant is being pumped into your engine.

[cactusjack]

Oh man, I've never seen a tank bubble like that. Maybe your thermostat is bad and it isn't opening at the proper temperature? Possibly a weak spring on the radiator cap?

I'm just taking swings at it here.

[dogdoc]

That bro is not normal. it appears your bike is running way too HOT if the coolant is boiling. Whats the boil point of anti-freeze?? really hot as I recall. Could be thermostat, could be temp sensors, fan, etc, etc. i would like to see a deealers eyes when he sees this problem. get it in and good luck.

[blowndodge]

could you possibly have air trapped? Have you bled the water pump bolt on the bottom of the pump to get all the air out?

[cactusjack]

I have been thinking about this some more...

Is the coolant boiling due to heat or is it percolating like air is being pumped into the bottle? Is the engine running when it's doing this, or is the engine shut off?

[ringadingh]

I would do a pressure test on the system, you may have a blown head gasket, or cracked head, etc. and its sucking some coolant into the motor and blowing it out the exhaust. Check your oil level also for being overfilled or traces of anti freeze.
It would be a good idea to rule these out just for peace of mind.

[macmac]

I would yank the thermostate right out and boil it in a can of water. Then I would not put it back in and run the engine that way for so long, maybe around town a day or two..

If it doesn't do it with out the T stat it was the T stat.. They can seized closed and this is what happens usually.

It may or not open in boiling water. You can add salt to the water since chances are this T stat is El Deado anyway.

I can't see the vidio, with the lousy connection I got.

[dogdoc]

That was my first choice too mac. it looks like your boiling anti-freeze inside the side reservoir, far OUT!

[madcow]

i had the exact same problem with my bike and solved it with some help from mac. first i replaced the thermostat, it worked when i tested it but i replaced it anyway. i also put on a new radiator cap, i then filled the system with a good quality coolant and bled the cooling system through the bleed screw located under the fuel tank next to the radiator filler which is acessed by removing the guage cluster. it took a long time to bleed and may even nedd to be bled a few times but it fixed the problem on my bike (a 98 nomad). the boiling sure does spin you out when you hear it, but its not an expensive thing to get right, its just a bit time consuming to get it bled right.

[mncruiser]

Thanks guys, it sure does sound like a seized T stat. Just before I took that video, the bike was running in the garage and the fan had just finished cycling. Shut the engine off and the show began. The coolant level goes way high and when the boiling settles down, all the coolant is sucked from the overflow tank and it goes bone dry. I did use the bleeder valve after a coolant change and got air for a while then all coolant was coming out but this was happening before I did the change.

[macmac]

When this happens the coolan in the engine side boils and is not replaced by cooler coolant from the rad.. The entire system works bassakwards or tries like hell.


If you were in a warmer location I might say to rip the guts of the T stat out and place the frame of it back in alone, but MN isn't a place where that idea would work. It will in summer, but not in cooler weather likey in Fall.

The engine would never reach full warm that way in Fall..

Another cause I have found on cars is a clogged up rad... That would be costly unless your soldering is most excellent.. My Bride and I did a 4 row chevy rad once. rodded that right out with a gas welding rod and I soldered the tank back on, but it sure was no fun.

These rads are far from cheap, so while if ever I might pull that stunt, I don't think many here would.

That is a good reason to change coolant and I do.

[cactusjack]

Originally Posted by macmac

When this happens the coolan in the engine side boils and is not replaced by cooler coolant from the rad.. The entire system works bassakwards or tries like hell.


If you were in a warmer location I might say to rip the guts of the T stat out and place the frame of it back in alone, but MN isn't a place where that idea would work. It will in summer, but not in cooler weather likey in Fall.

The engine would never reach full warm that way in Fall..

Another cause I have found on cars is a clogged up rad... That would be costly unless your soldering is most excellent.. My Bride and I did a 4 row chevy rad once. rodded that right out with a gas welding rod and I soldered the tank back on, but it sure was no fun.

These rads are far from cheap, so while if ever I might pull that stunt, I don't think many here would.

That is a good reason to change coolant and I do.

Good point. Dave (Misunderstood) had a problem with his Nomad when he first bought it and the problem was a clogged radiator. I can't remember what his symptoms were, though.

[phenrichs]

mac is right. that thing is running backwards. When the engine is running it can't get the coolant into the engine and it gets hot. When you shut it off it can pull the coolant through backwards. The "boiling" you see is the engine swapping coolant for air at a high rate. Tip up a beer bottle and drink it real fast. You see the same bubbles. Of course the cause to tip up the beer is happier than this case. I am going to tell bet that T-stat isn't opening.

[cactusjack]

Originally Posted by OP

mac is right. that thing is running backwards. When the engine is running it can't get the coolant into the engine and it gets hot. When you shut it off it can pull the coolant through backwards. The "boiling" you see is the engine swapping coolant for air at a high rate. Tip up a beer bottle and drink it real fast. You see the same bubbles. Of course the cause to tip up the beer is happier than this case. I am going to tell bet that T-stat isn't opening.

Better advice has never been offered. When I get home tonight I'm going to tip a few beer bottles up and test your theory.