EuroKClub
General forum area => K1200 / K1300 Forum => Topic started by: TomL on June 17, 2019, 12:48:58 am
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I've just returned from a 2,000mile trip to Scotland and unfortunately towards the end of the trip my bike started overheating. It first came to my attention towards the end of a good blat.
On the start of the long return yesterday, the bike got that hot on one occassion that the red overheating symbol flashed up on the display. I continued more slowly and eventually it just about came down again. The fan was running full time to no avail. I spent more time watching the temperature gauge than anything else.
I suspected that the problem was blocked cooling fins stopping the air from passing through the radiator. The other thought was that I might have a sticking thermostat or even a faulty water pump impellor or blown head gasket. All known problems on this engine.
Back home today I set about pinpointing the problem with an infra red thermometer and the belly pan, side panels and radiator cowl removed. With the engine at idle the temperature slowly rose and the fan cut in at four bars. The temperature increased to five bars and sat there with the fan going full time. The thermometer soon proved that the thermostat was opening and the radiator was getting hot all over.
With the engine revs increased to3,000rpm the temperature continued to climb until all bars were showing on the temperature gauge and I switched it off before the red overheating triangle came on.
The main problem with this cooling system is that the fan has to suck cooling air through the lower part of the radiator. The middle section of the radiator is totally blocked by the 4" wide mud flap. The fan is situated at the bottom of the radiator and can only suck air either side of the mud flap. The area at the bottom of the radiator either side of the mudflap gets all the crap off the front wheel. Despite hosing the radiator through from the back with the fan remove, the important area at the bottom of the radiator had become blocked again.
I didn't really want to drain down the system and thought about how to soak the rad in position. I managed to squeeze a plastic bucket into an oval shape and pushed it into position at the bottom of the radiator with a block of wood underneath to lift the edge of the bucket as high as the bottom hose. The radiator attachment lower bar has to be removed. The bucket is then filled with water to the brim and the rad is left to soak. That and hosing the rad from the rear got the rad as clean as possible.
Afterwards with the cowl and fan refitted, all was back to normal. As suspected the rad cooling fins were blocked with dirt thrown back by the front wheel. Although I'd cleaned the rad 6,000miles ago it had already blocked sufficiently to cause overheating. Perhaps soaking in position with the rad in the bucket will clean the rad better than just hosing through from the rear?
I had the same problem previously on my K1200S and it had ended up with having to get a new radiator which is not cheap. Hopefully this preventative maintenance will save me the cost of a new rad on this bike as well.
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I have been thinking about this one for a long time, knowing that it's in the pipework, so to speak.
I don't think we'll ever stop the rad clogging up, unless you can convince someone to build you one with a different fin spacing (I've tried & failed on that one - they've still got my spare rad, and now won't speak to me). Even if you did manage to get one built with wider fin spacing (which would at least allow cleaning), it wouldn't have the cooling capacity of the current one.
So, I'm looking at managing the problem, rather than solving it. Came up with a few ideas, haven't settled on one yet. Might do them all...:
How about an extra oil cooler? Cooler oil, less work for the rad in the 1st place. Problem is (on an 'S' at least), there's nowhere to put one except behind the current one (and therefore in the hot airflow). Would probably need a thermostat though - wouldn't want this in the circuit on a fast run.
Maybe a couple of slim 4 row rads down the side fairings? Plumbing them in will be a pain though. Doesn't help with cooling when you're slow either (which is the real problem), unless you fit it with fans.
Bigger fan? More powerful fan (with a manual override, so you can pre-empt the problem if you know you're about to crawl though a large city)?
Or just start a mileage based fund for regular rad replacement - about 2p a mile should do it.
Any more ideas?
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Once the overheating starts, it's a one way street. You can put off the inevitable for a while by cleaning as Tom has done but in the end it'll be a new radiator. I had this exact problem on my K1200GT. I cleaned the radiator a few time which helped for a while but in the end I had to bite the £566 bullet. That was some years ago and would obviously be more expensive now. Start saving Tom :-\
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One solution as being tested by one of the members (apologies for not remembering who - but maybe Sutty?):
- remove the plastic mud strip, because it doesn't allow any airflow through it
This releases about 10-15% extra surface area, but with the increased risk of stone damage.
Keeping the existing plastic grid (5mm gaps) will stop the really big stones, and it's probably worth adding an extender just to give some sort of balance between airflow and solid gunge hitting the now-clear centre of the radiator.
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We're still waiting on the results of that one Rich, while taking the louvre grill away will allow more airflow it will also allow more road dirt to hit the radiator, could be six and two threes. It will be interesting to know.
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Maybe moving the centre mud shield forward would allow more air flow?
If overnight soaking helps loosen the crud, I might rig up a timed water mist for next rad clean.
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Two things:
Firstly, back to the additional mesh screen. When I cleaned my rad prior to the Wrinklies, I removed the old Wunderlich framed mesh screen and was going to go the B&Q/Homebase/Screwfix mesh route. In the end I removed the mesh from the clunky frame and clipped it back in place in front of the OEM plastic grille. It reduces the stone gap to about half of the original and does a much better job of collecting dead flies etc.
Secondly, I didn't like the idea of losing the 'flying rock' protection of the bit in the centre of the rad so I was 'going to' drill 4mm(?) holes all over the solid rear of the central louvred 'mud flap' to get masses of air in to the centre of the rad. In the end I never got round to it but this part is easily removed with everything else in place so it might get done during this lifetime.
I'm happy with the stone protection of the two grilles and the 'rock' protection afforded by the central louvred mud flap. Drilling holes all over the back face shouldn't interfere with its rigidity as far as staying in place is concerned and it shouldn't affect its ability to deflect rocks etc. but hopefully the holes will help with airflow.
Of course, bits of flying insect gunge, micro-pieces of confetti and other assorted road 'grime' will also be allowed through and I have a feeling that this mod may require a more conscientious cleaning regime for the centre strip of the radiator in the future :)
As an aside, I changed the stock, plastic rock guard in front of the wee Honda radiator for one hewn out of stainless steel by an Ozzie outfit and it was while studying this new part that a third 'mod' for the K came to mind. The mesh and the holes are easy mods and are the low-hanging fruit.
My third option was to ditch the central louvred mud flap thingy and construct a 'similar' item out of aluminium but with the rear made of mesh AND with the louvres angled down at the rear (the stock item has the louvres angled UP at the rear which allows a straight-through path for stones flicked up from the bottom of the tyre). This will deflect rocks thrown UP by the tyre but allow air to flow into and through the radiator.
Slow day at Phmode Towers so where is my collection of 4mm bits... 8)
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Two musings on your good thoughts, Brian:
1. Lose the top half of the mud strip as a halfway house, with the assumption that an fender extender protects that area from direct hits
2. Consider increasing the 'scooped air' area, That would need ugly extensions to the fairing (lowers only?), but another 2-3" all round, say, would increase the captured air. Tricky to do well, methinks.
Maybe the Ducati race team can help us? They have a neat line in cooling spoilers:
(https://tmcblog.com/wp-content/uploads/2019/03/Ducati-rear-spoiler2.jpg)
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Hello guys, you were right Rich it was me that removed the plank crud catcher and it worked a treat, I bought 2 carbon fender extenders due to a mix up on fleabay but not got round to fixing them. I've ran it for 12 mths now and all is fine, no stone damage is evident but I'm still pondering changing the fan mount/shroud as I believe it restricts the air flow in the bottom corners, and the road dust and crud does not get blown through and so builds up. Plus with the shroud there you can't back flush the rad.
We went to LeMans last year and it was really warm it took us nearly 2 hrs to exit the bike park and the fan kept it all in check. four bars to five then fan on back to four bars and so on, as soon as we got on the ring road straight down to three.
I might add I don't really ride it in the wet, only when caught out.
Best regards Mick
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(https://i.ibb.co/N6gDcnw/IMG-1909.jpg)
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Sorry it's so big. The rad with the plastic guard removed.
Mick
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C'mon Rich do your thing and resize it ;)
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C'mon Rich do your thing and resize it ;)
Thing done!
All you have to do (having previewed the raw message) is add this inside the [img] bit:
[img width=1000]blahbalh
Users can then tap on the image to see the full size beast (or right click -> view image).
Applause can be found to the left of here. ;)
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Oh, go on then! Admins don't normally get applause but I'll make an exception this time 8)
As to losing the top half of the cow catcher, the top half is wide open anyway and is only there to stop the catcher flying off with the wind.
I don't really fancy a wind-deflector front end a la The Flying Scotsman on its inaugural run so that's out.
I think the bottom corners are a red herring and only make a difference because of the cow-catcher wotnot blocking off the central part of the core; get more air tjrough that bit and the bottom corners become an (almost) insignificant part of the whole.
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So, only seven hours to do a ten minute job...
First the bloody cheap-as-chips drill stand exploded and that took a couple of hours to fix...
Then I couldn't get the bloody cow-catcher off, having only fitted it two weeks ago...
Eventually, having stared at the area to be through-flow ventilated and compared it with my 4mm drill, I punched a whole pile of 7mm holes through the crud-catcher and would put up a piccie if I did such things and as Richard knows only too well, my iPhone just hates sending piccies to (especially) him so even he can't see it (and yes, I'm connected to bothe Wi-Fi and Mobile Data is turned on...
Anyroadup, it's not neat and it's not clever but no-one will ever see it and it wasn't an engineering apprenticeship test piece anyway, it was an exercise in aerodywotsits.
I shall report back if my K temperature guage never gets off the bottom rung...
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This is all it takes dirt wise to cause serious overheating. Very fine dirt carried in the wet off the front wheel totally blocks the critical cooling areas at the bottom of the radiator.
If you ride in the wet, this will happen.
(https://i.imgur.com/UdN6OPh.jpg?1)
The radiator cowl and mud flap laid on top of the fan. This illustrates how the mud flap blocks over 50% of the fan cooling area.
Testing with a torch I found that the lower 30% of the fan impellor area was totally blocked with dirt thrown up from the front wheel.
(https://i.imgur.com/OODH1YL.jpg?1)
A bucket can be eased into position as high as the bottom hose spigot. This is filled to the brim with water to hopefully soak and loosen the dirt prior to hosing through from the back to the front.
The radiator lower retaining rod has to be removed to get the bucket into a good position.
(https://i.imgur.com/wuusX8m.jpg?1)
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Good photos Tom, thanks.
A couple of points/questions:
- I can see a strip of crud pretty high up. Does that line up with the mud strip, above the solid part, or is it to the side? I've not seen mud/crud that high.
- how many miles has the bike done? It looks similar to the same level of wear & tear as my old rad (at 36k miles), but yours is a lot cleaner with the exception of the top mud.
<grandma-sucking-eggs>
Re: the mud high up, you might want to consider a fender extender.
I have a white mudguard with one fitted if you just want to try it for a few months, without having to drill/deface your existing mudgaurd.
</grandma-sucking-eggs>
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The radiator cowl and mud flap laid on top of the fan. This illustrates how the mud flap blocks over 50% of the fan cooling area.
Not mine it doesnt'! Many, many holes make air flow 8)
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Not mine it doesnt'! Many, many holes make air flow 8)
Photo?
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Text message failed. Sent by e-mail... ::)
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Good photos Tom, thanks.
A couple of points/questions:
- I can see a strip of crud pretty high up. Does that line up with the mud strip, above the solid part, or is it to the side? I've not seen mud/crud that high.
- how many miles has the bike done? It looks similar to the same level of wear & tear as my old rad (at 36k miles), but yours is a lot cleaner with the exception of the top mud.
<grandma-sucking-eggs>
Re: the mud high up, you might want to consider a fender extender.
I have a white mudguard with one fitted if you just want to try it for a few months, without having to drill/deface your existing mudgaurd.
</grandma-sucking-eggs>
I didn't really take too much notice of the high up mud because it was behind the mud flap. I guess that it got past the top edge of the mud flap and then ran down behind it. My bike has just passed 39K miles. I have hosed through the radiator at every service.
Recently I did Scotland, The Black Forest and The Highlands of Scotland all with a fair amount of rain. I'm thinking that the water off the road thrown up by the front wheel carries particles of fine sand/grit into the radiator cooling fins. The cooling fins are much smaller than on any radiator I've ever seen and it doesn't take much to block them up totally. The radiator acts like a sieve which allows the water through and traps the sand and fine grit.
I did try a fenda extenda on the K1200S and I wasn't too impressed with it. Trouble is that the rear part of the mudguard is fairly flimsy and the fenda extenda would flap about and rub on the tyre. I wouldn't fancy going back to a fenda extenda, but thanks for the offer.
The radiator cowl and mud flap laid on top of the fan. This illustrates how the mud flap blocks over 50% of the fan cooling area.
Not mine it doesnt'! Many, many holes make air flow 8)
How about a photo for us all to see Brian.
When I had the overheating problem in France on the K1200S, I took off the mud flap and rubbed it on a kerb edge to make a few air slots through it. A lot of work at the side of the road and it didn't make a lot of difference.
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I did try a fenda extenda on the K1200S and I wasn't too impressed with it. Trouble is that the rear part of the mudguard is fairly flimsy and the fenda extenda would flap about and rub on the tyre. I wouldn't fancy going back to a fenda extenda, but thanks for the offer.
You're quite right - and that's why I have a spare white mudguard!
I managed to pick up a carbon fibre mudguard cheap, and they don't flex much at all - so no chirruping from the extender I added to it.
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I did try a fenda extenda on the K1200S and I wasn't too impressed with it. Trouble is that the rear part of the mudguard is fairly flimsy and the fenda extenda would flap about and rub on the tyre. I wouldn't fancy going back to a fenda extenda, but thanks for the offer.
You're quite right - and that's why I have a spare white mudguard!
I managed to pick up a carbon fibre mudguard cheap, and they don't flex much at all - so no chirruping from the extender I added to it.
It's a shame that the carbon fibre manufacturer person who was going to make us an extra long carbon fibre front mudguard, disappeared into the woodwork.
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How hard can it be to take an existing mudgaurd and make a mould and extend it.
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How hard can it be to take an existing mudgaurd and make a mould and extend it.
Exactly what I thought.
It isn't ever going to happen though.
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All we need Tom is someone who has had a bit of experience with fibreglass.
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I know a man who says he can 3D print in titanium. I shall make enquiries.
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Carbon fibre and fibreglass are pretty similar to work with - they're both just plastic with reinforcement.
Problem with making a mould then a new mudguard is that the resin shrinks by around 5% (or more, depending on a few factors) as it sets, so as the mould is the same size as the mudguard, the new mudguard made from it is 5% smaller. It'll all look nice, until you try to fit it...
You'd need to take a moulding of the mudguard, somehow enlarge it by a pre-emptive 5%, then make new mudguard. It's not a problem I've ever found a good solution to.
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The first failed attempt at a longer mudguard was a firm who were happy to copy an original and extend it but then disappeared off the radar.
The latest outfit seem to only make small parts and don't like 'copying' the OEM design. They were happy to produce a longer fender extender, both above and below the 'normal' height, so that it reinforced the stock guard as well as giving clearance to tje tyre etc. etc.
I didn't think there would be too many takers for such an untried add-on and we know how relatively fragile the stock guard is up in the corners.
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For what it's worth I have a fenda extenda and have had to replace my radiator every 3 to 4 years. I have never had a cooling problem and it is always at the replacement plugs service that my dealer tells me the old rad is blocked and needs replacement. I am on my third radiator and expect to have to replace it in 2020. Hmm, those K1600 GT's are looking better and better!!
T.
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For what it's worth I have a fenda extenda and have had to replace my radiator every 3 to 4 years. I have never had a cooling problem and it is always at the replacement plugs service that my dealer tells me the old rad is blocked and needs replacement. I am on my third radiator and expect to have to replace it in 2020. Hmm, those K1600 GT's are looking better and better!!
T.
Take a good look at the K1600GT. IMO it will suffer from exactly the same problem.
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It begs the question why bmw can’t or don’t want to overcome the problem.
Could it be the case that they want the sale of radiators to continue.
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It begs the question why bmw can’t or don’t want to overcome the problem.
Could it be the case that they want the sale of radiators to continue.
They have overcome the problem, they ceased production of the K1300. :(
I expect that a change of mudguard would not have fully addressed the issue and thus more radical solutions would have been needed. Had there been an "extended/different mudguard" then it would also have been very obvious that BMW got it wrong to start with, something they really don't like being seen to admit to. The vast majority of "fixes" are implemented in a way that stops little Johnny, with his I Spy Book of BMW Bikes saying "Oh Look, that K1300S hasn't had the replacement switch gear, bevel box, cam chain jump guard and extended mudguard fitted"! :D
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Had there been an "extended/different mudguard" then it would also have been very obvious that BMW got it wrong to start with, something they really don't like being seen to admit to.
I reckon the mud strip is that admittance of fault. I don't recall seeing anything similar on another bike - BMW or otherwise - but someone will be along shortly to tell me I'm wrong. >:(
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OK, my pleasure. You're wrong 8)
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[t begs the question why bmw can’t or don’t want to overcome the problem.
Could it be the case that they want the sale of radiators to continue.
[/quote]
I doubt it. My first radiator was the original, the second they replaced for free (I know ... I couldn't believe it either!) so I have only really paid for the third on which went on after around 75,000 miles/ 7.5 years.
T.
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If BMW paid for a radiator you are a very lucky boy.
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That's like saying that the guy who drew first in line for the firing squad was 'lucky' 8)
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That's like saying that the guy who drew first in line for the firing squad was 'lucky' 8)
I know, but I have been subjected to the usual BMW brain washing which is why when it cost £566 I thought I'd had a result :-\
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:D :D :D :D
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This thread spurred me on to give my radiator a proper clean and it reinforced my belief that the Boffins at BMW got it wrong !
I had already removed the crud catcher plank over a year ago and that improved the cooling no end.
I stripped off the shrouds and the fan so I could reverse flush it. there was no damage to the rad at all, what I did notice was a build up of road dust to the whole rad but even more where the fan mount was, in my opinion this is what rots the rads.
Dry road salt gets trapped in the dust then as soon as it gets damp starts to corrode.
I gave it a spray of MucOff and flushed it out from the back and the whole rad was as clear as a bell.
The fan mount is going ! I' going to draw up a more open mount that will allow a better and greater airflow when moving and allow an easier way to back flush the rad without having to take it apart, I might even fit a bigger fan.
Best regards Mick
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Keep us up to date with some photos as you go, Sutty. It will be interesting to see the results.
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Will do Rich, the original fan looks woefully small for a 1300 and removing the restriction of the fan mount would allow a more forceful airflow to carry away some of the dust build up plus giving a bigger volume of cooled water available for when you are in traffic.
Regards Mick
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(https://i.ibb.co/0Dny272/bm-rad-mods.jpgwidth=1000)
Still pouring down here so I had a little play.
The red fan is the original at 7" dia plus not much sweep. I would make the housing from 3mm Stainless and machine out the mounting eyes. I put 3 sizes of fan 8", 9", and 10" but looking at I may be able to fit a 12"
I know the fan cowl is supposed to give a bigger draw area but I don't think it works in the real world, It may be causing eddies when the fans not running.
I've had a mooch through ebay and there's lots of fans to choose from.
I should have drew up the fan housing when I had it off but I think it will be OK for the rest of the year.
If you have any thoughts on this feel free to comment.
Best regards Mick
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Looks good!
Two things come to mind:
- on my radiator there's a lot less gunge up the top area, so the larger diameter fans will be pulling the air through cleaner fins = even better cooling
- are the larger fans just as narrow? I remember thinking the existing fan+surround were a bit tight in the space between the radiator and the engine.
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Good points all.
One other thing to consider is that the OE fan mount is solid to either side of the fan aperture.
This means restricted airflow when the fan is not running (i.e. most of the time) and I'm tempted to get my drill out and attack the flat portions between the reinforcing webs. If the air that does flow through the rad in the fan mount area has to 'spill' around the fan mount then that air is less effective than it would be with a holey mount.
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That was my same thought about the dirt that easly close the radiator because of the fan screen that guide the air flow when the fan is running but stop everything when it's stopped.
Rather than drill the screen (compromise the air suction when the fan is running) it should be better to havethe same mobile flaps used on some cars.
(http://i66.tinypic.com/2en6t21.jpg)
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Good points all.
Brian
Last week at Aldi i bought a wood burning iron kit, not for any reason but just because it was only £10. Inside there was a Hot knife attachment and I thought I could slice down the side of the ribs to let more air through.
Rich, there is enough room I think, some of the fans on ebay look quite narrow, with the shroud gone it would be easier to back flush
Vm5, I did consider fitting solenoid controlled flaps to the existing shroud that shut when the fan was energised, but i think that would be a mission too far
Best regards Mick
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One more consideration Mick. When I was thinking about changing the fan arrangement on my K12S, I thought of using stainless rod, 4mm dia. or so, to fabricate the fan mounting, much like the white frame outline in your mock up.
Easy enough to bend to shape and fashion the eyelets for the bolts, almost zero chance of stress cracks forming and almost zero wind resistance. It doesn't need to have the health and safety shroud cos no one in their right mind is going to go sticking their fingers in there...
And, we already have a precedent in the form of the radiator bottom mounting rod 8)
Of course, being a machinist that simple approach would be anathema to you :D
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Why not put the fan behind the radiator and blow (forward) through the radiator? Counter intuitive, perhaps, but the fan only does anything when you're either not moving or moving very slowly. That might help blow some of the mud out of the radiator.
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Hmmm? Blowing the hot air from the engine into the radiator may not be the solution...
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I'm sure you could get round that with suitable ducting. VFRs had the radiators on the side, presumably engine heated air wasn't a problem there as I don't remember them having any overheating issues.
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Vm5, I did consider fitting solenoid controlled flaps to the existing shroud that shut when the fan was energised, but i think that would be a mission too far
Best regards Mick
But the flaps used in these way lift themselves as soon as the bike gain a little speed. Otherwise, when the fan starts and create depression, they're automatically closed.
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Yes thats an easier solution but the shape of the shroud would make it difficult.
Regards Mick
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Am afraid no matter how many ideas are going to be put in place the problem will always be the crud and sand mixture used by road maintenance in your country during winder time , and (most unfortunately) due to its design simply loves the rad of K bikes so much. The only way is to change the rad £550 if I remember correctly .