Coolant advice needed...

Willi-P

New member
Gents, I could use a little advice regarding servicing the cooling circuit in my 2013 XC 250 please.

After my last ride, I checked the coolant level and found it was low. It was okay before the ride... I checked. After the ride, I could see no coolant in the radiator. Even when I lean the bike over to the left, none is visible.

A bit more info: The bike is basically new, it was a left-over 2013 with zero hours when I got it last November. I've put 6 or 8 hours on it since then... maybe 10. When I checked the coolant a few times before, I noticed there was funk in it. I could see little bits of floating matter in the coolant, there was stuff collecting on the top of the cooling fins, the radiator cap gasket and on the inside metal surface of the radiator fill "neck." I 've sorta wiped out the neck with a rag and the metal surface is not nice and smooth. I suspect corrosion is going on in there. Whatever's happening, it's definitely not cool (pardon the pun), and it needs immediate attention.

So I'm gonna drain, flush and refill. Also, I'm gonna get a KTM 1.4 bar radiator cap. Learned about that thanks to you guys here... thanks! Also read here about using vinegar mixed with distilled water for the flush.

Dang, it's taken me long enough to get around to my questions...

1.) What does vinegar do? Does it neutralize the corrosion process?

2.) I'm planning to use Motul Motocool Expert coolant. Any opinions on that? What coolant products do you guys like best?

3.) I searched and read a bunch of good info about how to go about doing this, but if y'all have any other advice and/or words of wisdom, I'm all ears.

Thanks guys!

Bill
 
Seems like an excessive amount of coolant being lost. Have u checked your bottom end oil? I know these bikes have had impeller problems.

I like to use Engine Ice for coolant.
 
As Terrence mentioned, I would check the transmission oil. The oil will look milky in the sight glass. If you have milky transmission oil, make sure to drain it and flush with ATF after you fix the leak and before you put fresh oil in. Those bearings do not like water/coolant much.

I like the Maxima Cool Aide, it's bright pink, so any leaks are apparent.
 
Wouldn't hurt to check the coolant, but imo you've nailed most of the problem.

A few have had poor casting/corrosion issues where the cap fails to seal properly and under pressure an excessive amount of coolant gets blown out the overflow.

I wouldn't bother with a new cap at this stage, and simply clean up the surface where the cap seals the best you can. If it's badly pitted I would consider some replacement radiators - cheaper than OEM by a long throw and many have reported decent quality considering they're ebay/china specials. Have a search around.

Fluid wise, you'll get a million opinions.. and there are a few options out there. Many recommend anything without added siliciates (I'm personally here nor there). Definitely go for Phosphate, Amine, Borate and Nitrite free. You can use Ethylene Glycol (not so nice to the environment), Propylene Glycol (OK), or any of the newer Organic Acid Technologies. Just be sure if changing from one to another to give the system a flush out.
 
The reason for the spirit vinegar/ water flush is I believe the acid helps remove any scale type build up and flushes out any remnants of previous coolant
 
My 2013 300 lost coolant on a long ride that ended in a steep long 4th gear melt down. I think it may have been improperly torqued head bolts from the factory. You might want to check that. Mine were hand tight.

In all fairness, the head got so hot that the o-rings were completely disintegrated and I only checked them after it burned down. So there just may not have been much tension left. Still, most all my motor bolts were little more than hand tight. Anyway. Just something easy to check...
 
Thanks guys!

Okay... I'll check my transmission oil for coolant (hope none's in there)... look into possible replacement radiators (hope that's not necessary yet)... think I'll just do the impeller upgrade as a preventive measure... check head bolt torque (definitely want to avoid a repeat of stang's "4th gear melt down").

A couple more quick questions about flushing the cooling circuit:

Should I use a 50/50 mix distilled water and vinegar?

Is there a particular kind of vinegar to use? (I was gonna use white vinegar.)

Should I fill the cooling system with the water/vinegar mix and run the bike till it reaches operating temp, then shut down, let cool and drain? Then refill with coolant?
 
Not sure it's a very good idea to flush it with vinegar/citric acid when you have signs of corrosion. It might break free some parts that are actually kept together by the corrosion and you might start to have leaks. I think you should use it when you have circuit contamination by oil .

You can flush the circuit with normal water until appears to be clean and then flush it again with distilled water. Take all the water out by adding the coolant, flush it until all the water is gone and then fill it up only with coolant.
Go out and do your Sunday ride, let it cool and flush the coolant again. Fill it up again with coolant and that's it. After each ride check the coolant deterioration, and flush it every time it gets too contaminated. It will never be perfect but after 3/4 coolant flushes it has improved a lot. Get "ready to use" coolant of a good brand .
 
Check Impeller?

Thanks for all the great advice guys!

After searching and reading and searching and reading, I think it'd be a good idea to at least check the impeller. i plan to flush and refill today but I do not have a replacement impeller or a gasket right now. Looks like pulling the cover off is no problem, but I'm concerned about reusing the gasket.

FYI, my friends and i plan to ride this weekend, so if i can't reuse the gasket (or make a replacement), I'll be out for the ride.

Is the gasket reusable? (I generally don't like to reuse gaskets, but will in this case if it works.)

Another option would be to go to the auto parts store and buy a sheet of gasket material so I could make one.

Suggestions?
 
Thanks for all the great advice guys!

After searching and reading and searching and reading, I think it'd be a good idea to at least check the impeller. i plan to flush and refill today but I do not have a replacement impeller or a gasket right now. Looks like pulling the cover off is no problem, but I'm concerned about reusing the gasket.

FYI, my friends and i plan to ride this weekend, so if i can't reuse the gasket (or make a replacement), I'll be out for the ride.

Is the gasket reusable? (I generally don't like to reuse gaskets, but will in this case if it works.)

Another option would be to go to the auto parts store and buy a sheet of gasket material so I could make one.

Suggestions?

Might not be reusable, sometimes it's glued to the case . Mine was and broke when removing the cover . Don't risk it or you might not go riding after.
 
I've never had any luck with the water pump gasket coming away cleanly. Without a spare I wouldn't risk it.
 
Got 'er done...

Resisted the temptation to remove the water pump cover thanks to y'alls advice. i'll do that later when a get a gasket. Flushed the funk out... took six flushings. By the end, water came out nice and clear and there was no more matter visible through the radiator filler neck. Filled with fresh Motul Motocool Expert and screwed on a new KTM 1.4 bar cap. Figure I'll ride tomorrow, then drain and refill one more time and that should be good to go for a while.

Thanks for your advise gentlemens!
 
1.4 bar seems low to me, i've always used 1.8 and rarely have a boil over, if i do, first thing i check is the radiator cap, i've at least 3 go on me now over a couple of bikes.
...
 
What did the "floating matter" look like? Was it black and stringy? If the inner head gasket o-ring leaks, it can pull radiator coolant into the combustion chamber, and blow spooge into the coolant.
 
Hi Jim,

Don't think that's the problem... at least I hope not.

The stuff inside my radiator was a sorta white-ish, or light grey, crud that, when I'd rub a little chunk between my fingers, it kinda broke down to a gritty consistency. There was a good bit of it in there. It took 6 good flushes, 7 if you count the flush after my ride, to get it cleaned out enough to make me happy. The stuff had tendency to stop things up particularly if allowed to dry. For example, the little overflow port in the radiator filler neck was completely stopped up with it.

I still don't know what it was, maybe it was the old coolant breaking down or maybe corrosion or maybe a combination of the two. Anyway, things are looking pretty good in there now.
 
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