Weird coolant issue - MVAgusta.net
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 09-13-2015, 01:21 PM Thread Starter
Senior Member
 
squidger's Avatar
 
Join Date: Sep 2014
Location: Horley Surrey
Posts: 258
Weird coolant issue

This past couple of weeks my bike has developed a weird coolant issue. After a ride out I get home and in the time it takes me to get out of my leathers a puddle of coolant about 12 inches in diameter appears under the bike. It's coming from the overflow pipe. Weird thing is this has happened about 6 times now and the coolant level hasn't dropped. It wasn't overfilled before. It sits just under half way up the expansion tank. Usually the only way a bike can "make coolant fluid" is if the head gasket leaks and oil is introduced to the water causing the level to rise.My head gasket seems fine. Maybe I have a coolant fairy filling it up when my backs turned. Any ideas?
squidger is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 09-14-2015, 10:25 AM
Senior Member
 
Ackers's Avatar
 
Join Date: Jun 2013
Location: Dorset, UK
Posts: 2,210
New Site Garage
If oil was getting into the water you'd know about it, your expansion tank would look like its filled with a frothy Latte

Have you checked it is coolant and not fuel? Just a thought but if you like to fill up just before you get home from your ride and you fill up stood on the bike, when its tipped over onto the side stand fuel leaks out of the overflow?

Interested in anything that Sucks, Bangs and Blows!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Ackers is offline  
post #3 of 11 (permalink) Old 09-14-2015, 01:14 PM Thread Starter
Senior Member
 
squidger's Avatar
 
Join Date: Sep 2014
Location: Horley Surrey
Posts: 258
Definitely coolant.
squidger is offline  
Sponsored Links
Advertisement
 
post #4 of 11 (permalink) Old 09-14-2015, 03:27 PM
Senior Member
 
Join Date: Mar 2009
Location: Shropshire, wide open spaces
Posts: 291
Does the bike hold the correct temp when riding ?
Could be, and I stand to be corrected, the expansion/ filler cap may not be holding pressure allowing the coolant to expand. Only a thought
And in turn, would raise the coolant temp

Last edited by jeteast; 09-14-2015 at 03:30 PM.
jeteast is offline  
post #5 of 11 (permalink) Old 09-15-2015, 10:34 PM Thread Starter
Senior Member
 
squidger's Avatar
 
Join Date: Sep 2014
Location: Horley Surrey
Posts: 258
Bike runs at normal temp. Expansion tank level is just under half way. Expansion tank filler screw is now just turning and not undoing which I believe is a known issue and will be replaced under warranty at next service which is being done next month. I think it's still sealing as if it wasn't the coolant would boil earlier due to lack of pressure.
squidger is offline  
post #6 of 11 (permalink) Old 09-16-2015, 01:39 AM
Senior Member
 
dudman's Avatar
 
Join Date: Apr 2013
Location: Cirencester, UK
Posts: 560
The correct coolant "level" is very low almost empty in the expansion tank, if you keep filling up it will keep spiting it out through the overflow. My thoughts are if you can see a trace of water in the tank its fine.
dudman is offline  
post #7 of 11 (permalink) Old 09-16-2015, 10:07 AM Thread Starter
Senior Member
 
squidger's Avatar
 
Join Date: Sep 2014
Location: Horley Surrey
Posts: 258
Agreed. But if it's spitting it out you would expect the level to drop until it drops enough that it stops spitting it out. My level isn't dropping thats the weird part.
squidger is offline  
post #8 of 11 (permalink) Old 09-16-2015, 10:29 AM
Senior Member
 
Join Date: Dec 2014
Location: UK
Posts: 581
Squidger, I'd say to just keep an eye on it, it will stop. I found out a while ago that my Ronda doesn't like to be filled to the brim with coolant. Too bad the dealers didn't know this when she went in for her service.

She spat it out again. That lasted a few rides. Now she is happy again

Kag
Kageira is offline  
post #9 of 11 (permalink) Old 09-17-2015, 03:48 PM Thread Starter
Senior Member
 
squidger's Avatar
 
Join Date: Sep 2014
Location: Horley Surrey
Posts: 258
Think I've found the problem.

I couldn't figure out how I was losing fluid but the level stayed the same in the expansion tank.

Today I stripped the bike down and removed the radiator filer cap. This enabled me to see that the radiator was not full and needed topping up. This is obviously the result of losing fluid.

The radiator cap has 2 seals (upper and lower) when you fit the cap the upper seal seals the point of contact at the top of the radiator neck so no fluid leaks out of the radiator when the system is pressurised. The lower seal fits on the bottom of the neck and seals the radiator internally so no fluid is allowed to pass to the overflow hole which is connected to a tube which goes to the expansion tank.

When the system reaches a certain pressure a spring is compressed lifting the lower seal and allowing a flow of coolant to the expansion tank. When the engine is stopped the pressure decreases to a point where a vacuum is generated which opens the little valve in the centre of the radiator cap allowing coolant to flow from the expansion tank back into the radiator.
I have to surmise that there is a fault with my radiator cap and this valve isn't opening. So my bike has been filling the expansion tank up when at normal pressure but not returning fluid to the radiator when cooling down. Fluid is then escaping from the expansion tank via the overflow hose returning the expansion tank level to normal but leaving the radiator level low. So when I check the expansion tank level all looks good and I appear to be losing fluid but the level never drops.

Have removed the radiator cap and exercised both valves and they seem to be OK. Gonna take the bike out tomorrow and check the expansion tank level when hot to see if its rising and again when cold to see if it falls as it should. Then when I get home I'll check the radiator level again. I may have to replace the radiator cap if all is not well. But at least I now have an explanation for the weird fluid loss with no apparent level change.
squidger is offline  
post #10 of 11 (permalink) Old 09-17-2015, 04:31 PM
MVAgusta.net Sponsor
 
mitchy's Avatar
 
Join Date: Feb 2010
Location: Gold Coast, Australia.
Posts: 5,016
New Site Garage
Send a message via Skype™ to mitchy
Fit a new radiator cap and all should be good.Coolant not returning to the radiator when motor cools down.Common problem with that style of cap.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Bike- F4 1078 312rr
Work.Email & Paypal.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Work Phone (+61)0755244655
Facebook- Mitch Covington
Mobile-0423041326
mitchy is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to use all of the features of the MVAgusta.net site, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome