2006 XC-w coolant smell

[craig3x]

at certain times, none in particular, I smell that "burning coolant" smell. Can't really tell if it's coming from the tailpipe or somwhere else. the bike does not leak, and the coolant is always full when I check it. what's going on here? Anyone else experience this?

[cubera]

I know the smell. Maybe it's a little drop burning off the pipe since the overflow tube connects to the frame and drains down that way. Smells like diet Maple Syrup:lol:👍

[craig3x]

I hope that's the case.

yes, that's the smell. but not sure if i've ever seen diet maple syrup!

anyone else have any ideas?

[Mike in Fresno]

thats probly it, just a drop or two, dont worry til it steams up or you can see it dripping.

[craig3x]

ok...rode again today and the bike never overheated (no boiling or steaming), but I keep smelling that coolant smell. I'm really concerned about this. Could it be burning it in the engine? How would coolant get into the combustion chamber on this bike? This is my first KTM, and I was told they don't have head gaskets, but use an O-ring instead. Is this true, and could it be letting coolant into the combustion chamber?

[Mike in Fresno]

look for white corrosion or the color of your coolant around the edge of the head and bottom of the cyl. Check the inside of the rad neck where the cap makes its seal and the cap and its rubber too. Also consider replacing the rad cap with a new one, they do go bad and this can be a symptom of a bad cap too..

[craig3x]

look for white corrosion or the color of your coolant around the edge of the head and bottom of the cyl. Check the inside of the rad neck where the cap makes its seal and the cap and its rubber too. Also consider replacing the rad cap with a new one, they do go bad and this can be a symptom of a bad cap too..

that all make perfect sense, and great ideas. But there is no coolant leaking externally anywhere. That is why I am so concerned. The smell starts almost immediately upon start up. After 4 hours of riding, I did notice the coolant level dropped only about 1oz. of coolant.

[Mike in Fresno]

and to what level is the coolant now when you look in the rad cap opening? Is it above the fins, below the fins or??

[RAZ227]

at certain times, none in particular, I smell that "burning coolant" smell. Can't really tell if it's coming from the tailpipe or somwhere else. the bike does not leak, and the coolant is always full when I check it. what's going on here? Anyone else experience this?

This is so funny, because I have a bullet proof 05 300 MXC, and just over the weekend I had the same thing happen to me. No leaks anywhere, and the bike runs strong wth no coolant missing:confused:👍

[craig3x]

This is so funny, because I have a bullet proof 05 300 MXC, and just over the weekend I had the same thing happen to me. No leaks anywhere, and the bike runs strong wth no coolant missing:confused:👍

...and you are smelling that "burning coolant" smell also? My friends 2006 300MXC always boils over after hard riding, or hill climbs. you can hear it

I did notice that after a 4 hour ride, my coolant was about 1/2 cup low. So it is going somewhere now. My guess is it's being burned in the engine. The smell starts right at start up, so that eliminates it being dripped on the exhaust and burning off. It would take the exhaust a few minutes at least, to get hot enough to burn drops of coolant.

So my question is, how is it getting in there? what are the possibilities?

[craig3x]

anyone?

[Mike in Fresno]

a bad cap is a possibility or something in the cyl/head or hoses are it.

[craig3x]

a bad cap is a possibility or something in the cyl/head or hoses are it.

what do you mean "something in the cylinder head"? wouldn't coolant be having to leak into the combustion chamber? has to be the o-ring gaskets, right?

[RAZ227]

...and you are smelling that "burning coolant" smell also? My friends 2006 300MXC always boils over after hard riding, or hill climbs. you can hear it

I did notice that after a 4 hour ride, my coolant was about 1/2 cup low. So it is going somewhere now. My guess is it's being burned in the engine. The smell starts right at start up, so that eliminates it being dripped on the exhaust and burning off. It would take the exhaust a few minutes at least, to get hot enough to burn drops of coolant.

So my question is, how is it getting in there? what are the possibilities?

I spent this afternoon going through my bike and my coolant is right where it needs to be. I ride the piss out of this bike and ride some really technical stuff and have never had a boiling over or not even a trace of steam off this bike. I'm taking the bike out again tomorrow and I'll see if I still smell it.

[Mike in Fresno]

craig, not trying to be an ass here, but you keep asking and now you need to start doing some of the suggestions and work thru it. There are several possibilities and you gotta do the work. Start with the easy or cheap stuff first. It could also be as easy as you are over filling the rad. What level do you fill it to and where is it after you said it needed 1/2 cup of fluid? I asked this before and you didnt answer.

[craig3x]

when I took the cap off, the coolant was below the top row of fins. 1/2 cup low. I filled it so that thefluid was above the top row. Did not fill it to overflow.

Yes, I understand it is time to "start doing". I ordered some new topend o-ring gaskets, but no one has said this could even be a possibility.

AGAIN, external leaks are ruled out, due to the fact that the burning smell happens immediately upon start up. This is telling me the coolant is being burned in the engine. Hoping these o-ring gaskets fix the problem. I guess I could also have a warped head, but hoping not.

[Gary jp4]

You are probably right about the leak being inside the engine if it doesn't smell before you start and then smells immediately after start like the first few seconds before it has a chance to warm up.

If you are giving up on the outside and going inside this is just a reminder of some places you could have water leaking into the engine to smell it coming out the exhaust. Some places to look for.

Inner head o-ring

Cylinder base gasket

Exhaust/Power valve cover o-rings or sealant leak

Cracked exhaust /power valve cover

Cracked head

Cracked cylinder

Cracked case

Warped head (still leaking through the inner o-ring) (possible but unlikely)

If you smell it right away at start up and then it tends to go away as you ride the inner head o-ring could be leaking. Leaks here should be worse, as far as burning it, after it is run (not so much while it is running) as the cylinder pressure is low and water pressure is still up. Then when you start it next you have some coolant in the cylinder. Not that it wouldn't leak while running but it would usually over pressurize the cooling system from combustion pressures and come out the cap and through the cap overflow hose while it was running.

Any of the areas above that leak inside the engine would most likely continue to leak after shut down for the same reason above and smell most at start up.

In those cases there should be some visible water inside that did not vaporize when cooled down.

Start by inspecting closely when you take off the exhaust, inside the PV cover/exhaust flange, etc.

With the symptoms you are describing I would think an internal leak is likely in an area not under so much pressure as the combustion chamber. More like the exhaust /PV cover, cylinder crack in this area, or cylinder base gasket leak.

[craig3x]

Thanks gary. I am going to start with replacing both of the O-ring head gaskets. If that doesn't fix it, I will check out the powervalve area

[Gary jp4]

I wouldn't just throw them in. If you find something there then great. I would inspect the area looking for a definite cause and if you don't find one keep on going and look at those areas before you put it back together.

[craig3x]

I wouldn't just throw them in. If you find something there then great. I would inspect the area looking for a definite cause and if you don't find one keep on going and look at those areas before you put it back together.

well, i will do that, but it seems like actually visually finding the cause may be tough. How can I tell by looking if the O-rings are bad? or if I pull off the PV cover, how do i know if the gasket was bad, etc. seems like I just have to try things