fan cutting in early

[Jerh Heffernan]

I bought a really nice K100lt last week, I notice that the fan and temp light are activating after about 10 miles. the temp gauge is reading that the bike is not even half way , so it is not over heating. it is obviously an electrical problem. for the moment for short rides I have removed the relay switch under the tank to disable the fan, It is only  6 to 8 degrees C at the moment in Ireland but I am looking for a long term solution. any suggestions what is wrong with my cooling system?

[Laitch]

Welcome, Jehr.

It's good that your fan works; often they don't on bikes not ridden in warm or hot conditions. How are you certain your gauge is accurate? Verify that your coolant system has sufficient coolant in it. Is your overflow at "max" and return line not pinched?

Assuming the temperature gauge works and therefore the combo pump works, try cleaning the contacts in the standpipe temperature sensor electrical plug. If the fan doesn't shut off after a minute or two while sufficient coolant is circulating, that sensor may be wonky. Take a look here.
http://www.motobrick.com/index.php/topic,6702.msg45766.html#msg45766

Then take a stroll through the cooling system section, if you haven't been there already.
http://www.motobrick.com/index.php/board,103.0.html

[The Mighty Gryphon]

The fan is controlled by a temperature sensor installed in a stand pipe located on the front of the cylinder head just behind the radiator.  This sensor also sends information to the Jetronic engine control.  It is NOT the sender that drives your temperature gauge.

First, I suspect that your gauge is ok.  In this time of year, your engine should run at about the midpoint of the temperature gauge, but the fan should NEVER come on.  The fans on these bikes normally only activate when stuck in traffic in hot weather.

The sensor for the fan turns on the fan when the sensor wire gets low resistance to ground so the first thing I would look for is worn insulation someplace that allows the wire to short out to the frame or engine.  I would also look at the fan relay itself. 

Since this same signal is used to control the fuel mixture, is there any sign the engine is running lean when first started and it is cold?  Does it have a rough idle and frequent stalling?  I am suspecting the sensor, as there have been a number of problems seen here that were related to bad sensors.  Look there first.

[Jerh Heffernan]

Thanks for the reply. great forum, just discovered it. This is my 6th K and its the fist time I've heard a fan running. Even in rush hour traffic in Barcelona. First of all the bike hasn't been ride much in the last 2 odd years by the previous owners. I have just ridden it 3 times on short trips since the fan came on the first 2, and not the 3rd because I had removed the relay.
The fan and light came  on 2 times after about 10 miles but didn't stay on rather cutting in and out and the temp light was going off and on. now I haven't investigated thoroughly but I do intend over the Christmas holidays starting with changing the coolant. the expansion bottle is at the right level but that is an expansion bottle which doesn't mean there is enough coolant in the rad. It starts on the button lovely and warms up and has a crisp response from the throttle, I haven't had a K in a 8 years but I sold my Paris Daker boxer Gs and wanted a K100. so I am a bit rusty on mechanical issues and instead of looking in the dark I said I'd look for feedback from other K rides who might have had simulator problems.
There are 2 sensors at the base of the front of the engine on the left side looking from the front. Do the both do the same job? I removed the cover of the relay and it looks fine inside to the naked eye no burn marks or loose components. so I am guessing its one or both of these sensors. Ill give them a good clean and pop the relay back in and see how it goes. if people have anymore sugestions I would gladly value them/ Thanks very much for your Help.

[The Mighty Gryphon]

The two sensors you are talking about are the oil pressure and temperature gauge senders.  They are not the one that controls the fan.  That one is behind the radiator just in front of the throttle bodies.   It is mounted in a vertical pipe that has two hoses connected to it.  You have to remove the radiator to get at it.

[Jerh Heffernan]

So today as known in Ireland as St stevens day I decided to do some spannering to my K, First thing Wa now more riding   no coolant whatsoever. so i flushed my rad 3 times with 30 litres of clean water, refilled the system with a 50?50 mix of coolant/water. replaced the relay and took a 30 mile ride and hey presto. everything is fine. no idiot lights , no fan. i am delighted.  Thanks to everyone who contributed to my post. great service. now more riding less spannering.

[Martin]

Jerb it's a good idea to only used demineralized or distilled water in your cooling system. Straight tap water can contain lots of nasties that will eventually harm your cooling system.
Merry Xmas Martin

[johnny]

greetings...

today is known as boxing day here in canada... i would go for a ride butts im flushing my system with high fiber local molasses british columbian weed butter cookies...

j o

[Martin]

Johnny do you wish to swap your famous weed butter cookie recipe for my Grandma's Xmas Koala Pie.
Regards Martin

[Jerh Heffernan]

yeah Johnny I am currently flushing my own system with SOUTH African Merlot .

[Laitch]

MOTOBRICK.COM—An Internet site for health-consciousness.

[johnny]

south african merlot... that ch1t will make you whack...








lets trade...

i takes all the weed i can carry and grind it into a powder with a small mill stone from an old corn mill...

i fill a cast iorn bucket with as much butter as i can carry...

i melts the butter over a oak fior... as it melts i adds the weed sturing constantly...

when all the weed and butter have become one i remove it from the fior...

then i letts it cool while sturing constantly...

i getts me some cookie dough from the stoar... when they come outts of the oven i spoon a piece of that weed butter on each cookie... and sometimes i just spoon a piece right in my mouth... its good for my complexion...

anyway... once the weed butter is absorbed by the cookie i putts them in buckets and putts them in the ice box for later consumption...

i gotts me a batch of weed butter cupcakes on the counter right now... had weed butter french toast earlier today... had mashed potatoes and weed butter yesterday... weed butter... it aints just for cookies anymoar...

j o

[Martin]

Thanks Johnny  you need the following one Koala 2 bottles Scotch or Bourbon, pre rolled pastry (I can't be bothered to make it myself ), potatoes, carrots, onions. salt, pepper, strong hessian bag. First sample the Scotch to test quality, then find a tree with a Koala in it. Shample the Scotch again to give you courage to climb the tree. Crimb the tree rememberz to bring bag otherwize you will have to go back for itz, shample the Scotch again Koalaz can be vicious. Grabz da Koala shample Scotch andz fallz outa da tree. Shamplez da Scotch again putz cheezed off Koalaz in bagz. Shamplez da Scotch. Peelz all da veggies, shamplez da scotch it's thirzty workz peelingz. Rollz out da pastryz. Take large sharpz nife and stabz yourself in da handz. Usez da scotch to dullz da painz. Letz Koalaz outa da bagz ,Koalaz taste like sh*t finizh of da scotch and pass out.
Regardz  Smartnz

[johnny]

greetings...

i ended up getting this koalaz outa da tree and into the bagz... it was vicious like wolverine... pushed a box of sharaz over there and it gotts tight like a pussy...

skinned it and ate it like a rabbit on the spitt... was tasty for sure...

was as good as shamplezing da scotch and borbun...

j o

[Martin]

Your Koalaz look a lot different than ours, maybe US Koalaz are better and more tasty, ours taste like Sh*t. If I ever get to the US I will try one.
Regards Martin

[The Mighty Gryphon]

Getting dem koalas outta the tree is a lotta work JO.  Much easier to scrape 'em off the road in the mornin'.