K11 Owners Group

beemeerr11 · Flying Brick Rider Joined: 05 Mar 2006 Posts: 168

The bike has been running quite hot, even on cold days it won't take long to sit at the lights and have the thermo fan come on, Mad

I have pulled off the water pump cover and all is O.K. I have replaced the Thermostat, old one was O.K. I have flushed the radiator ,I have now bought the rubber gaskets for the Radiator cap.
If this doesn't work, my last option is to take the radiator from my spares bike and try replacing it? Crying or Very sad

So when the bike gets that hot that the thermo fan comes on, should I see a change in the hight of the fluid in the overflow bottle? Reason I ask is that no matter what the temperature of the bike is the fluid in the bottle doesn't move?

Lou
95LT

Scott_Anderson · Posted: Mon Jan 23, 2012 8:57 am Post subject:

The water level should move a little bit, level low when cold and then higher when hot. just like in your car.
If the level isn't moving at all, check to make sure that the tubing between the tank and the filler neck connection isn't kinked or blocked/plugged, try the entire rad cap from your parts bike, make sure you really have the system filled complete and purged of air.
You are using a 50/50 mix of coolant and distilled water. Not tap water.
Are you using am oem bmw t-stat? The bmw design uses the t-stat as a 3-way type valve so a "normal" stat won't work. There is a generic stat on the market that some other users have used, but it's not an exact match so I don't think it works as good as OEM.
When the fan is coming on, is the water temp acutally that hot?
Could be a water temp sensor starting to fail.
The sensor that turns the fan on is behind the radiator and screws into the water fitting that bolts down on the top of the block.
_________________
Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

mikey11000 · Joined: 04 Dec 2011 Posts: 21

Might be worth pulling a spark plug to make sure its not running unusully lean although i doubt it.Also the first thing i would be checking is the thermo switch for the fan,it maybe coming on to soon.If the rad is flushed and pump is ok theres not a lot left.Have you been able to check the hoses to make sure there all heating up? also to check there not rock hard and under pressure.
_________________
1997 k1100lt se

Moondog · Posted: Mon Jan 23, 2012 9:45 am Post subject: Re: Running Hot Question.

I agree with the above solutions but I have to ask how long have you had the bike? Are you new to the k-bike? The reason I ask is that the k-bike is notorious for being a "hot" bike. I helped my heat issue by installing a K100 radiator in my K1100. My temp needle stays a needles width below the half way mark most of the time, down from the half and 3/4 mark before the radiator change.

Do a search here and you'll see many different ways that have worked and not worked. Also some riders don't have issues with heat so there is no rhyme or reason.

Inge K. · Posted: Mon Jan 23, 2012 12:15 pm Post subject:

It also been examples that the front of the radiator been covered with much bugs and muck, which have restricted airflow.
Clean with compressed air in the reverse direction.

Inge K.

beemeerr11 · Flying Brick Rider Joined: 05 Mar 2006 Posts: 168

Thanks for the reply guy's, to answer the questions, I have replaced the thermostat with the genuine one, I have had the bike for 12 years, it had 50,000Ks on it then and now has 210,000K's I have replaced the temp sender unit? When I flushed the Rad I also blew out all the bugs etc, I'ts quite surprising how much gathers in there. The bike use to run at well below half on the temp gauge, it now runs between half and just over, with in a few minutes, when the temp gauge gets near the red line, the thermo fan comes on as you would have expected, so that side is working O.K.
I'll disconnect the over flow tube and check it out, change the radiator cap, and see what happens from there. If I start both bikes from cold, the spares bike thermo fan will come on about 10 minutes after my regular ride bike, I have also let the bike idle from cold with the Rad cap off to elimenate any air lock issues?

Cheers

Lou
95LT

mikey11000 · Joined: 04 Dec 2011 Posts: 21

Well i hope i can put as many miles on mine lol.ok Anyway i just wonderd if before you replaced the thermostat with a new one it was doing exactly the same as it is now? (taking the same amount of time before the fan came on?)my theory which i have seen many times is that the old thermostat allowed the engine to run a little cool ,not closing 100%due to age.then the thermostat fails causing the bike overheat.You change the thermostat with a new one and it runs a little hotter than ever before but is correct. My k1100 gets up to temp very fast as it should .I started it from cold the other day to balance the throttle bodys and with an air temp of 5 degrees the fan was on within 5 to 10 mins.On the road the gauge reads about half but creeps up fast if im in traffic,soon drops when fan kicks in or i move away. Any way its just a thought but i would still check to see if its running lean and the rad cap replaced.The only other thing i can think of is a head gasket failure blowing combustion into the cooling water ways.
_________________
1997 k1100lt se

Moondog · Posted: Tue Jan 24, 2012 8:28 am Post subject:

Scott_Anderson · Posted: Tue Jan 24, 2012 9:08 am Post subject:

I can relate to different bike with different characteristics.
My '97 fast idles better and warms up faster than my '95, but....
the '97 also has 1/2 the miles on it and the '95 has a 3 cor rad in it.

Theoretically the warm up time shouldn't matter as the rad is mostly bypassed until the stat opens, but the '95 is slower to warm up. T-stat leaking by? possibly, but neither one of them is overheating.
_________________
Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

kstones · Posted: Sat Jan 28, 2012 7:57 am Post subject: overheating

Hello; when you filled with coolant did you lean the whole bike over to the left? the bottom hose to the left side of the rad is level even dipped so forms an air block and stops a lot of fluid being put in; so tipping and squeezing that bit of tube gets the air out and you can get quite a bit more in and be sure it is full no air locks. After running the level is down to the first bend in the hose or so, and overflow to the header bottle won't happen normally.
Tony.