ADVrider

Go Back   ADVrider > Bikes > GSpot > Parallel Universe
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 05-26-2011, 05:24 AM   #1
JRWooden OP
Beastly Adventurer
 
Joined: Jul 2008
Location: The great state of confusion
Oddometer: 4,111
What makes the radiator fan come on?

So ... yesterday ... I'm riding down the interstate in 95F degree weather the gauges are all fine. I pull off and drive about two blocks to my hotel and as I pull into the parking lot I get splashed in the face ... what the heck did I drive thru a sprinkler???

Nope the coolant tank had overflowed and thanks the the clever cap design I took it in the face ... I look down and the OBC computer is flashing overheat (it had just started) and the radiator fan is NOT running. Hmmmmmmmmmmmmmmm

I turn off the bike coast to a parking place wait a minute and re-start.
Still flashing "overheat" and still no fan ... after about 10 seconds THEN the fan comes on ....

I checked to see if there was any debris in the fan shroud but it was clean... it seems to be some kind of fault, but later in the day the fan came on as normal (with the temp reading still at four bars).

Is the fan acutated from the coolant sensor that runs the fuel injection or is there a 2nd sensor for the fan?

Any thoughts appreciated!
JRWooden is offline   Reply With Quote
Old 05-26-2011, 06:31 AM   #2
CheckerdD
Beastly Adventurer
 
CheckerdD's Avatar
 
Joined: Apr 2005
Location: Dave Rankine, Reno NV
Oddometer: 1,267
Interesting problem for folks used to air cooled bikes. Per my Haynes manual if Coolent temp. displays on instrument cluster, and no engine warning light shows there, then temp sensor is not at fault. Again per Haynes you cant test the sensor except to stick a multimeter set to k-ohms to measure resistance between terminals. It should be around 3.17. I don't think you have a faulty sensor for this reason. The computer uses water temp to decide whether to richen the fuel mixture (if cold) or lean it for operating temp. (Think choke). You did not say the bike was running irregularly.

The sensor "is located on the rear of the cylinder head inboard of the cam chain tensioner and oil pressure switch (see illustration p, 3-5)."

I am thinking there might be something wrong with your thermostat. That is at the bottom of the radiator and it opens and closes to let the coolant circulate. If it stuck closed, it would produce the symptoms you experienced. If you trust it has fixed itself fine, if not you want to replace it. Dave
__________________
Pavement! We don't need no stinkin pavement.
CheckerdD is offline   Reply With Quote
Old 05-26-2011, 09:56 AM   #3
JRWooden OP
Beastly Adventurer
 
Joined: Jul 2008
Location: The great state of confusion
Oddometer: 4,111
Cry

Tks - I was not sure if the fan might have a separate sensor ... Sounds like it does not!

And yes bike runs normally so I expect the "shared" sensor is ok.

It just happened again - same conditions
90 degrees pulled off interstate on side of road to chk map
And got splAshed again. It seems to be a "transient" thing

Odd than bike never overheat
EXCEPT Under these circumstances ... I've put 300 miles
Of highway speeds between the two incedints temp has been
Steady

Odd it is..
JRWooden is offline   Reply With Quote
Old 05-26-2011, 10:27 AM   #4
Bayner
Beastly Adventurer
 
Joined: Mar 2008
Location: Penticton, BC
Oddometer: 1,457
I love the way they vent that thing right into your face! Clever, very clever.

I also had overheating when a portion of the rad was blocked with crud. It was very dusty, and then wet, so I assume it clogged up enough to slow the airflow so the fan could no longer keep up. Anything above 10mph and it was fine. Rinsed it off well, and that was that.
Hope you get it sorted....
Bayner is offline   Reply With Quote
Old 05-26-2011, 10:46 AM   #5
L.B.S.
Beastly Adventurer
 
Joined: Feb 2010
Oddometer: 1,170
If it's any consolation, my 2009 F800ST spits it's coolant out onto the frame, on top of my right leg and towards my crotch.

I haven't had any overheat temps/flashing warnings problems surface (yet) only the coolant spewing all over.

I'm told the "remedy" for this is to lower the level of coolant in the reserve tank to just barely touching the MIN level mark.

That little bit less coolant shouldn't effect operation in any bad way, but might possibly prevent an unwanted dousing.
L.B.S. is offline   Reply With Quote
Old 05-26-2011, 10:55 AM   #6
The Griz
North Forest Rider
 
The Griz's Avatar
 
Joined: Nov 2008
Location: Minnesota
Oddometer: 3,778
It's pretty straight forward really. Your bike isn't overheating when at speed (50-80mph) because there is enough air moving through the radiator to properly cool the coolant, even at 95 degrees F. However, when you pull off of the freeway and ride slower (15-40mph), at 95 degrees F there simply is not enough air moving through the radiator to cool the coolant properly. In those conditions at a low speed, the cooling system temperature sensor is supposed to sense the higher temps, send the signal back the computer, and then the radiator fan is supposed to turn on in order to move more air through and keep from boiling over. In 95 degree weather riding slow, a radiator fan is a must. Take that bike in and get that radiator fan working under warranty. I would not ride it slow in those conditions again until the radiator fan is working. Doing so is extremely hard on many engine and cooling system components. Good luck.
__________________
PAUL BUNYAN FOREST RIDERS MC
2013 KTM 300 XC-W
2014 KTM 690 Enduro R
The Griz is offline   Reply With Quote
Old 05-26-2011, 01:36 PM   #7
sturgeon
Studly Adventurer
 
sturgeon's Avatar
 
Joined: Jun 2007
Location: Great White North
Oddometer: 911
Check to make sure nothing's obstructing the fan blades; it doesn't take much. I had a small pebble block mine. Although I guess if yours came on eventually, nothing was blocking it, or it fell out. You should be able to spin it easily with your fingers. With the key off

Mine will come on in 20C (70F) weather after idling for 2-3 minutes when the engine's warmed up. On for maybe 30 seconds, then cycles off again.
sturgeon is offline   Reply With Quote
Old 05-26-2011, 07:59 PM   #8
JRWooden OP
Beastly Adventurer
 
Joined: Jul 2008
Location: The great state of confusion
Oddometer: 4,111
Cry

Thanks all ....
I have arrived at an intermediate destination
And spent a bit Moore time in the problem

At this point when I start the bike and let it idle
It will come up to mid-range on the temp display.
Then after a couple more minutes the fan does
Come on and is moving a good amount of air.
I have checked the fins of the radiator
And they are clean .... Yet even with the fan running
The temp will still increase to 6 bars and
Then the over temp warning starts ....

I had the water pump replaced under warrant
Due to leakages a few weeks back, and
Am now thinking maybe there is air in the system.

I have a copy of a post from Joel that talked about
How hard it was to purge all the air from the
Cooling systems on the 800 so I'll give that a go tomorrow
When the sun is out
JRWooden is offline   Reply With Quote
Old 05-26-2011, 08:22 PM   #9
The Griz
North Forest Rider
 
The Griz's Avatar
 
Joined: Nov 2008
Location: Minnesota
Oddometer: 3,778
Quote:
Originally Posted by JRWooden View Post
Thanks all ....
I have arrived at an intermediate destination
And spent a bit Moore time in the problem

At this point when I start the bike and let it idle
It will come up to mid-range on the temp display.
Then after a couple more minutes the fan does
Come on and is moving a good amount of air.
I have checked the fins of the radiator
And they are clean .... Yet even with the fan running
The temp will still increase to 6 bars and
Then the over temp warning starts ....

I had the water pump replaced under warrant
Due to leakages a few weeks back, and
Am now thinking maybe there is air in the system.

I have a copy of a post from Joel that talked about
How hard it was to purge all the air from the
Cooling systems on the 800 so I'll give that a go tomorrow
When the sun is out
Good call and good luck!
__________________
PAUL BUNYAN FOREST RIDERS MC
2013 KTM 300 XC-W
2014 KTM 690 Enduro R
The Griz is offline   Reply With Quote
Old 05-27-2011, 06:32 AM   #10
JRWooden OP
Beastly Adventurer
 
Joined: Jul 2008
Location: The great state of confusion
Oddometer: 4,111
Question

Looking ath the bike this morning I find that there is not a copper sealing washer under the bleed screw .... I could have sworn there used to be one before the water pump exchange ?

Would some one mind looking at their bike?

It is the top screw on the back of the pump ...

Thanks
JRWooden is offline   Reply With Quote
Old 05-27-2011, 06:44 AM   #11
CheckerdD
Beastly Adventurer
 
CheckerdD's Avatar
 
Joined: Apr 2005
Location: Dave Rankine, Reno NV
Oddometer: 1,267
Yup. It has a washer and the Haynes manual says it is important to put in a new one. Just to confirm your talking about the "bleed bolt." There is also a washer on the "drain bolt." If I was on the road I would go to a True Value Hardware. They have the best selection of odd and end bolts and washers. If it's copper it's because it's supposed to squish. Do a search with your computer to find the nearest. Dave
__________________
Pavement! We don't need no stinkin pavement.

CheckerdD screwed with this post 05-27-2011 at 06:53 AM
CheckerdD is offline   Reply With Quote
Old 05-27-2011, 06:52 AM   #12
JRWooden OP
Beastly Adventurer
 
Joined: Jul 2008
Location: The great state of confusion
Oddometer: 4,111
Thanks Dave !

Yes sorry for any confusion, I am talking about the bleed bolt on the water pump housing (the drain bolt has it's washer intact) .....

It has not been leaking coolant at that bolt ... Perhaps it has been ingesting air. :-(

Damn .... my schedule for this trip was already tight
JRWooden is offline   Reply With Quote
Old 05-27-2011, 08:05 AM   #13
JRWooden OP
Beastly Adventurer
 
Joined: Jul 2008
Location: The great state of confusion
Oddometer: 4,111
Hmmmmm

I think that indeed it may be ingesting air ...
I rode just a short way this morning and the
Bike is almost completely cooled down yet the overflow tank is
Well above the "full" mark. When i left on the trip it was at full but
Now even after two face wash episodes it is full-er
Sigh
JRWooden is offline   Reply With Quote
Old 05-27-2011, 02:43 PM   #14
lmclamore
Citation Collector
 
lmclamore's Avatar
 
Joined: Jul 2010
Location: Washington DC area
Oddometer: 404
I had the exact same symptoms last summer. It ended up being a bad radiator cap. Cap replaced and all has been fine since.
__________________
"An expert is someone who has made every mistake possible within a very narrow field of inquiry"
-Niels Bohr
lmclamore is offline   Reply With Quote
Old 05-27-2011, 09:40 PM   #15
RedHawk47
Adventurer
 
RedHawk47's Avatar
 
Joined: Oct 2006
Location: Berthoud, CO
Oddometer: 373
Quote:
Originally Posted by The Griz View Post
It's pretty straight forward really. Your bike isn't overheating when at speed (50-80mph) because there is enough air moving through the radiator to properly cool the coolant, even at 95 degrees F. However, when you pull off of the freeway and ride slower (15-40mph), at 95 degrees F there simply is not enough air moving through the radiator to cool the coolant properly.
I had a similar problem in a trip in Mexico. My radiator on my KLR had a leak and we "fixed" it with stopleak. After zipping down the highway and then getting stopped by construction the stopleak would fail; happened several times. But riding down and up the hill to Batopilas - no problem. And riding into Juarez, slowing 10 mph every mile or two - no problem.

So basically - hot engine, not enough cooling. I agree with checking your radiator cap - if it's not holding enough pressure the coolant may not be getting hot enough to trigger the fan switch. Also check your coolant. I think antifreeze also has a higher boiling temperature.
__________________
Dan
It's never too late to have a happy childhood. -- Tom Robbins
13 Moto Guzzi Stelvio NTX
09 BMW F800GS
99 KLR 650 A13
RedHawk47 is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

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

Forum Jump


Times are GMT -7.   It's 11:46 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014