Coolant discharge - why?

[Therapy]

I am calling it discharge as it came out the overflow tube from the radiator cap.

About 40 miles into a ride.
The last few miles were low speed. 15-30mph.
We stopped for a couple of minutes and then idled around a parking lot for 2-3 min.
We stopped so my older son could put in his ear plugs and he said I was leaking something.
It was coolant out of the radiator overflow tube.
I shut down and it spit a few cups and stopped.
It was another 40 miles home and it happened once more at a stop light.
At a couple more it spit just a few drops.

No idiot lights lit up.
All lights lit and went out when starting up, as usual.

There is now just a tiny bit of coolant in the recovery tank at the very bottom.

1185 miles on the bike so you know that on Monday I will be asking Honda to take a look at it.

Upon arrival at home I took some temp readings of my bike and the older sons' NC too. All in °F.

MINE HIS

Radiator side just under the cap 190 181
R top of cyl. just below valve cover 153 157
Center top of cyl. front 184 177
R side of R cyl. base 201 182
L side of L cyl. base 211 201

I can think of several things it could be.
What say the mechanics here?

I have a video of it spitting but I don't know how to post it without having to join some "free" site or organization (think evil)........Plus it is from an iPhone so it is a .mov.

 

[lootzyan]

Too many possibilities, too many "or this".
If you don't have enough experience you can only check a radiator cap (only when cold).
First of all - did you notice a cooling fan come on? If not that is separate branch of questions - faulty temp sensor or fan relay (or fuse).
Next - faulty thermostat (didn't open fully) or radiator blocked (maybe by air), faulty water pump, and on and on ...

 

[itlives]

I'm thinking you had an air bubble work it's way out.
I would take it in if it was mine , too.

 

[Therapy]

lootzyan,

I figured it could be some of those things but never thought about a bubble.
Though it is a 2013 it is only a month or so old and will be "their" problem. I am just nosy and want to know everything including if I can figure it out.
I should have made this a poll.......with a prize.......Heh.

 

[L.B.S.]

lootzyan,

I figured it could be some of those things but never thought about a bubble.
Though it is a 2013 it is only a month or so old and will be "their" problem. I am just nosy and want to know everything including if I can figure it out.
I should have made this a poll.......with a prize.......Heh.

My brand new BMW F800 constantly peed coolant out it's reservoir, (down the fairing and onto my right leg and boot, the awesome design, there) along with many other owners reporting the same thing. The only solution was to make sure the coolant reservoir was always at the low mark, and never higher.

I wouldn't be completely alarmed; but do take it in and explain to your dealer the situation. A cursory check should reveal any anomalies like a fan unplugged, or a bad rad cap, etc. If everything is ruled out, then just keep a close eye on it and continue, with maybe a check of the coolant level more frequently added to your riding routine, and observe the differences if any, with fluid levels and results pre and post rides.

I wouldn't get too caught up on the tank level, as long as there at least was some fluid in evidence near the low mark, versus none. Remember, it will constantly vary a bit when hot or cold anyway, and the open or closed condition of the thermostat, etc.

 

[kharli]

the radiator cap seal isn't the best ive seen and the paint comes away easily ,might of caused a wee gap , another thought is a thermostat problem . my coolant tank stays slightly overfilled at all times after overfilling after a valve check. I assume this isn't a problem as would just vent off . I don't think an air trap would cause problem .. |The worst case is a head gasket problem ......

 

[Saturday Morning]

Ok, i'm reading through the posts above - This sounds like a classic case of a problem radiator cap, but i'm getting hung up on some of the descriptions used in the original post:

Keeping in mind that:
The overflow tube from the neck of the radiator should connect to the bottom nipple on the coolant recovery tank.
The overflow tube from the top of the coolant recovery tank should discharge to the ground.

In order for any coolant to make it out onto the ground, the coolant recovery tank must be completely full and overflowing which can be indicative of:
1. An initially overfilled coolant system that needs to normalize.
2. A bad radiator cap that is not holding pressure:
3. A boil-over condition due to overheating or a mechanical failure.

First double check that the hoses are properly connected, that nothing is plugged, and clean the rad cap. If the condition does not improve replace the cap.

-Saturday

 

[Therapy]

Ok, i'm reading through the posts above - This sounds like a classic case of a problem radiator cap, but i'm getting hung up on some of the descriptions used in the original post:

Keeping in mind that:
The overflow tube from the neck of the radiator should connect to the bottom nipple on the coolant recovery tank.
The overflow tube from the top of the coolant recovery tank should discharge to the ground.

In order for any coolant to make it out onto the ground, the coolant recovery tank must be completely full and overflowing which can be indicative of:
1. An initially overfilled coolant system that needs to normalize.
2. A bad radiator cap that is not holding pressure:
3. A boil-over condition due to overheating or a mechanical failure.

First double check that the hoses are properly connected, that nothing is plugged, and clean the rad cap. If the condition does not improve replace the cap.

-Saturday

Oh dang!
I better bone up on coolant systems. Of course the radiator cap vent goes to the tank. DuH! I will trace (or look in the manual) for the tube that was venting coolant to the ground. Any thoughts on the temp measurements?

The reservoir is basically empty.

 

[Saturday Morning]

Is it possible that the radiator overflow hose has slipped off of the plastic nipple on the bottom of the coolant recovery tank, or that the plastic coolant recovery tank has a crack in it? If either were true then what you experienced could be completely normal and this could be a super-simple troubleshoot.

If you get a chance, remove the lower front fairing to get a good look at the hose connections and the plastic coolant recovery tank. (Remove the (2) 5mm Allen head bolts and pull the plastic fairing out away from the side of the bike - not towards the front) Maybe you'll get super lucky and find a loose hose or misplaced hose clamp. If everything checks out visually, remove the black plastic fill cap from coolant recovery tank and fill it to the top line with clean water to see if it any water leaks right back out indicating a crack in the tank.

With the bike still under warranty I wouldn't attempt any repairs beyond the loose hose/misplaced hose clamp scenario. Good luck and don't forget to drain back out the water in the recovery tank and top it and the radiator off with fresh Honda coolant before replacing the fairing.

-Saturday

 

[Therapy]

Saturday,

I don't know what I was thinking when I posted saying the overflow was going straight to ground. It is a normal system.

All connections are fine. Heck, it's brand new - just sat on the floor for a long time. I refilled the system per manual and purged air like it said to. All full up now. I could see (good) flow in the fill opening while burping so I think the pump is doing it's job. No leaks. I hope I just have a bad cap.

It was missing a little over half of it's capacity (OUCH) but never a light came on. The fan did not come on during the purge and the engine never got to temps measured yesterday on either bike.

While burping I saw a couple of flakes floating around. They looked like paint flakes - dark grey.

The only reason I did the service I did was so I can get it to the shop. I don't have a trailer. Hopefully I can ride up and they can see it like I did. It squirts and the stops and then does it again....... 10 min later.

But since it is new and in warranty (2 months on Thurs.) I will take it up to the shop when they say I can come and let them figure it out.

 

[Saturday Morning]

Thanks for posting back. It's crazy for that to be happening on a new bike. I'm sure that they'll get to the bottom of it though.

-Saturday

 

[MZ5]

Head gasket.





....is another possibility.

Hope it's a bad cap.

 

[Therapy]

Head gasket.





....is another possibility.

Hope it's a bad cap.

Really!!
I don't want it to be anything but a bad cap because I will be PEEEOOOD if some big system has to be gone into at 1000 miles. FER SURE!!

 

[kharli]

even if the original cause wasn't head gasket ,head gasket problems are sure when ridden low on water ,not particularly prone the nc engine looking at the design ,but as it doesn't have much water in the first place. some engines have very little head room for the water expansion tank or rad ....aka my vw lt40 and running that low on water after a hose leak to a garage warped my cylinder head .. sometimes theres debris from the casting impedes water flow on a particular spot and that causes local expansion which can cause intermittent blowing into the cooling system .. usually the remaining water will look slightly oily and sometimes water gets into the oil giving a creamy colour on the oil filler cap or dipstick .
this is intended for general information ,not to worry you !!

 

[Therapy]

even if the original cause wasn't head gasket ,head gasket problems are sure when ridden low on water ,not particularly prone the nc engine looking at the design ,but as it doesn't have much water in the first place. some engines have very little head room for the water expansion tank or rad ....aka my vw lt40 and running that low on water after a hose leak to a garage warped my cylinder head .. sometimes theres debris from the casting impedes water flow on a particular spot and that causes local expansion which can cause intermittent blowing into the cooling system .. usually the remaining water will look slightly oily and sometimes water gets into the oil giving a creamy colour on the oil filler cap or dipstick .
this is intended for general information ,not to worry you !!

It didn't work.
I am a "worry wart" and over check, over analyze, over build and over maintain everything I own.
Maybe that is why my stuff lasts a lot longer than others with the same stuff?

 

[Therapy]

So.
I got an appointment for tomorrow and they let me drop the bike off today.
It was not blowing coolant when I arrived.
I get a call right after I got home and the "service rep" calls to say I have a screen on my radiator and that could cause it.
They did not have an answer when I asked why the thing would blow coolant and not light the warning light. Nor to the question of the multitude of people that have aftermarket radiator guards. Nor to the fact that we have three NCs with screens on the radiators and only mine is blowing coolant.......or to the almost identical temps taken from the motor of another after the same ride.

I'm not liking the vibes thus far.

 

[670cc]

So.
I got an appointment for tomorrow and they let me drop the bike off today.
It was not blowing coolant when I arrived.
I get a call right after I got home and the "service rep" calls to say I have a screen on my radiator and that could cause it.
They did not have an answer when I asked why the thing would blow coolant and not light the warning light. Nor to the question of the multitude of people that have aftermarket radiator guards. Nor to the fact that we have three NCs with screens on the radiators and only mine is blowing coolant.......or to the almost identical temps taken from the motor of another after the same ride.

I'm not liking the vibes thus far.

Yep. Typical dealer stonewalling.

 

[showkey]

Therapy..........asked prior by others.........did you ever verify the FAN was coming on at hot idle standing still ???

 

[kharli]

good point ,but then there is the issue of why did not the temp warning light come on ,which it should just before boil off under pressure 105 degC I think . I hope its something simple ! After 43000 miles on dirty roads I have only one small fin dent so I personally am not convinced of the need for one but at 450 quid a replacement I can understand the need ! though at that price I would get another similar and bodge it on if mine failed and was unrepairable!

 

[Therapy]

Therapy..........asked prior by others.........did you ever verify the FAN was coming on at hot idle standing still ???

No, I did not. I made it home and shut it down and took temps. The next day I refilled the system and ran it long enough to burp the air out. The fan did not come on during that process. It was only a few minutes. I could see good flow of hot coolant and the bubbling had stopped. Temps after that process were not recorded but were much lower than after the ride. (above post)

I then took it straight to the shop this morning.

It is only almost two months old and has about 1000 miles on it.