Overheating

[oliverjb]

The other day I drained and replaced the coolant and now find my 00 i/s is running very hot. The coolant in the tank is not flowing to the rad. I don't know if this is a cap problem or thermostat or water pump. I plan to start with the cap and wondered if anyone knows of a generic replacement. BTW the bike was fine before the coolant change.

Thanks

[Patrick]

How much coolant did it take??  Is the cap sealing properly ?? Is the radiator full ?? Is the coolant circulating?? I'm just wondering if its air-bound..

[oliverjb]

It took pretty much a gallon, the cap is sealing tight but the coolant is not flowing to the tank from the rad. I ran it til the fan came on with the cap off but the rad stayed full.

[RP#62]

You need to be more specific.
"my 00 I/S is running very hot" - based on what?  You have a temp gage and its running hotter than before, the fan comes on more often that it used to, you're getting an overheat light, or it just seems like its hotter than it used to be?

"the coolant is not flowing to the tank from the rad" - you mean the overflow tank?  There should be very little flow.  When the coolant is hot and expands, when the pressure builds up in the radiator, it will relieve through the cap to the overflow tank.  When you shut the bike off and it cools down, it creates a negative pressure and sucks coolant back into the radiator from the overflow tank.  This of course if providing your cap is sealing properly.

The first question I'd have is did you "burp" the radiator as called for in the service manual after replacing coolant.  If not, you could have air in the hoses/passages that could cause it to run hot.
-RP

[oliverjb]

I can just "feel" the heat as I ride. I do think my fan is coming on more than normal in traffic. I have "burped" the rad 2x with no difference.  Everything worked fine prior to the coolant change and maybe it is just the GM orange coolant. I will have the cap pressure tested ASAP to start.

[Earl in Pensacola]

If you didn't have an over-heating problem before you changed the coolent, then my guess is that either (as previously mentioned) there is an air pocket or the rad. pressure cap isn't sealing to the radiator.  Have you tried insuring a seal by bending the cap "tangs" slightly, so as to tighten it's grip to the rad.?

[Patrick]

You're using dex-cool ??!!

[Jeff K]

You're using dex-cool ??!!

Oh, oh... here we go! 

I remember 10 years ago people were all wound up about dex cool being a horrible coolant. But it never panned out in the Valk world.

[KW]

It the cap was bad/not sealing, wouldn't it leak/boil out when hot?

[oliverjb]

This is the first time with the Dex Cool. I will go try bending the tabs to see if I can get a better seal.

Thanks

[Robert]

Is this a trick question? Or even a real one? Lets see you ran the engine till the fan came on and no fluid came out of the radiator

It took pretty much a gallon, the cap is sealing tight but the coolant is not flowing to the tank from the rad. I ran it til the fan came on with the cap off but the rad stayed full.

The coolant overflow tank is just that a over flow tank and not part of the cooling system perse. Its only function is to catch the overflow now if you have the cap off and the engine running and the coolant is at the top and not boiling out its not overheating. If you run the engine with the cap off and the radiator fan cycles its not overheating. If the coolant light is not on its not overheating. Get a infra red gun and tell us the readings. ??? At 65 degrees where you are that's enough to put out some heat.

I can just "feel" the heat as I ride. I do think my fan is coming on more than normal in traffic. I have "burped" the rad 2x with no difference.  Everything worked fine prior to the coolant change and maybe it is just the GM orange coolant. I will have the cap pressure tested ASAP to start.

The fan cycles in traffic NORMAL yes maybe a bit more but all in all normal. Some times when we touch something every little thing becomes super critical and there's nothing really wrong. The psychology of repairing your own bike and the fear it will be toast add alot to the maybe somethings wrong factor.

[Jeff K]

The coolant overflow tank is just that a over flow tank and not part of the cooling system perse. Its only function is to catch the overflow .

Wrong.
The coolant reservoir is a crucial part of the coolant system. The expansion of the coolant forces the coolant into the reservoir and when it cools and contracts the coolant is drawn back into the radiator, It is a big part of the overall cooling system.

[Robert]

Bike will live without it and as long as the coolant level is ok will not overheat. But its not like the radiator that you can see the coolant move in it or a integral coolant tank that is part of the cooling system that coolant actually flows through the tank and is pressurized like the radiator. its just a catch can with no pressure and with the cap off I would like to see the coolant level in the tank change while hes watching it. Hes says the bike is overheating and contributing it to the coolant tank, wrong. Now if the coolant isn't being sucked back in then that's another problem and has already been addressed. As another note hes looking for the coolant to go into the tank with the cap off running it to temp and then putting the cap back on, not going to happen.

[MP]

In the AM, with the bike cold.

1. open rad cap, and check that radiator is full.
2. take off left side cover, mark on the overflow bottle liquid level.
3. ride bike until hot.
4. mark overflow bottle liquid level, should be higher than when cold
5. let sit until AM, then check bottle level cold.  should be lower than when hot, back to same level as previous AM.

If the above is true, then the overflow system is working properly.

MP

[BudMan]

In the AM, with the bike cold.  etc etc etc
MP

Well said.  Good test.

[B]

If you're not seeing flow & you can't get it to 'burp' there's a good chance you thermostat is not opening.   

[Red Diamond]

The coolant overflow tank is just that a over flow tank and not part of the cooling system perse. Its only function is to catch the overflow .

Wrong.
The coolant reservoir is a crucial part of the coolant system. The expansion of the coolant forces the coolant into the reservoir and when it cools and contracts the coolant is drawn back into the radiator, It is a big part of the overall cooling system.

If the debate is not over, I would like to add a .01 worth. As said before, the overflow tank is not a part of the cooling system. It is a part, in that it is an environmental part. The old systems simply had an overflow tube that emptied on the ground (hince, environmentally unsafe for animals). Now the overflow tank catches the coolant when it overheats and boils over into the tank. The overflow tank cools nothing. It holds the coolant until the radiator cools and is engineered to vacuum the coolant back into the radiator when it cools, keeping the radiator at normal level. If there is too much coolant in the overflow tank to begin with, it will overflow. Now if the thermostat in not opening, the engine will get hot quickly, you will definently know it. It is also normal for you to feel heat coming from the road surface in extremely hot areas. (Texas, etc).

[Gryphon Rider]

Did you mix the coolant with distilled water per the jug's instructions considering how cold the bike might experience during storage, or was the coolant pre-mixed?  If you used undiluted coolant, it will NOT cool as well as properly mixed coolant, as the water you mix with it is better at absorbing heat from the engine and releasing it into the radiator than straight glycol coolant.

[oliverjb]

Thanks to all who replied and commented. I bent the tabs down on the cap and went for a long ride yesterday. The old girl feels normal again. I had forgotten about bending the tabs as I do believe I had to do that the last time I changed the coolant.