Yamaha R3 Forums banner

Coolant / temp question (air leak?)

9K views 14 replies 6 participants last post by  proneto911 
#1 ·
Hi guys, posting out of desperation, any feedback welcome. I'm kinda at the end of my rope here. Try to keep it short and sweet:

My bike seems to be getting air into the coolant. Diagnosing does not show it (no bubbles in radiator visible when cap open and running), but I have a feeling there is due to the following symptoms:
1) temp starts rising, more easily with every few rides. To the point where just sitting at a light I can get ALL THE BARS
2) problem goes away for awhile when I change coolant the proper way, thus bleeding all air out. But only with a full flush, the ol' rocking the bike left and right while running it doesn't do diddley.
3) problem is, I have to do it like once a month.
4) i noticed there seems to be a leak from my overflow tank. At the top hose, just some green crusty stuff around there. BUT the coolant levels never go down, or far enough for concern. Never requiring top up. Just the temps going up.
5) Extra maybe relevant info: Bike has been laid down at the track twice, bit of coolant came out of the reserve I think. Has been inspected by Yamaha, and no other evident leaks from water pump/radiator hoses etc. other than overflow tank mentioned above. Crash was only aesthetic damage, plus a new handlebar / steering head bearing / footpeg / exhaust.


What would you guys do? Where could the air be coming from? What should I try and replace first, without just doing the whole coolant system? Really hope to find some help pleeeeease!
 
See less See more
#4 ·
Good ideas from both above. I'll mention only as an added thought. MILC mentions the article/video and the radiator fan. Do you know for sure the electric fan is working? If not, additional heat, plus added pressure on the system could force the radiator cap beyond it's limit, and cause it to release pressure. Possibly your leak?? I doubt it, but it could happen. Anyway, in case you need it, the fuse for the radiator fan motor is in the #5 slot in the fuse box and is a 7.5amp. The fuse box, for the individual circuits, is located behind the center panel. (Owner's manual for 2015 is page 7-31, 32). Good Luck. Munchkins are a bugger to find.
 
#5 ·
Thanks all for the suggestions! Yeah I've changed the coolant a few times (myself and also at the dealer) with the same result, only when I do it, it happens again quicker. The dealer do it with the syringes and proper tools to ensure air stays out, so it takes a bit longer for the problem to come back, but it still does.

The fan kicks on consistently, and it does it's job in regulating the temps for about 15-20min, shorter rides to work and such. After that, it just keeps creeping up like the fan can't keep up with it anymore. Longer rides, followed by traffic stops or even uphill climbs will send it into dangerous temps for sure.

I think I will follow the suggestions and start with replacing the plastic parts, namely the overflow tank, and the hoses going into it. Fingers crossed I can find the problem eventually!
 
#6 ·
I don't mean to be contrary, BUT, you said the fluid levels do not go down? Why begin replacing parts for an unknown problem? To start with, stop changing your coolant. It's obviously not fixed the problem up until now. The coolant doesn't need topping off, so it's not leaking out. AND unless you're seeing unusual amounts of white smoke out the exhaust, coolant's not being sucked into the engine through a leaking head gasket. The motor fan's running, that's good. You definitely have a problem, I'm just suggesting your money would be better spent on a proper diagnosis of the problem. I could tell you why I believe that's a smarter route to a fix, but I'm too busy moving around unused various replacement parts from numerous projects to give an answer. Random, replacement parts get expensive in a hurry, and seldom cure the problem. Spend your money on a proper diagnosis. Again, not to be contrary, it is indeed your money to spend, and you may stumble onto a fix. But it can be a long frustrating road to get there. :nerd:
 
#8 ·
Sorry to have sounded so blunt. I'd probably find another Dealer/tech to look at my bike. If you've done as you said, they're either not hearing you, haven't had the time to properly diagnose, or aren't open-minded enough to consider something unusual. Have they even considered doing as you said? Checking the thermostat or water pump? And though highly unlikely, some sort of temperature sending unit, or even the water temp gauge itself? You shouldn't feel forced to make a decision on selling, parking or damaging your R3. Where's the next closest Yamaha dealer.? I'm all in favor of staying with Yamaha dealers. Because I know no independent techs of any value at all, around me. The best they can do is half-assed work on V-twins and bolt up add-on bling. You may be blessed with several good techs.. Somebody is capable of finding the problem. Don't give up.
 
#9 ·
That's it for Yamaha dealers anywhere around me, sadly. But I might take it to another tech, I know the owner and although they charge a bit more, they really know their stuff working on sport bikes and setting them up for race etc. Hopefully I'll have time next weekend - thermostat or water pump would be my first instinct, so I'll start from there. I'll try and put a few more miles on it so the problem is really apparent before going in, she's running kinda ok for the moment, but a week or two max should bring the gremlins out again.
 
#15 ·
Yeah my first instinct from just dealing with cars would be the thermostat. It’s a smaller machine but if it’s overheating without it spilling out I’d say the thermostat is done and need replacement. I see it occasionally on cars the coolant overheats and causes bubbles into the reserve. And adds pressure to the entire system. And overflows at the relief valve and sprays everywhere.


Sent from my iPhone using Tapatalk
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top