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2021 S1000RR Weep hole leaking coolant, what is really happening inside?

23K views 55 replies 13 participants last post by  bennymx  
#1 · (Edited)
Jump to this comment for the DIY fix

I have joined the weeping weep hole crowd with my 2021 S1000RR @ 6000 miles.

I'll try to be brief but here is my timeline, and then a couple questions:

  • At 2000 miles I upgraded my exhaust and noticed while the panels were off that my coolant was near the low line. Never saw a leak and everything underneath was dry at the time, so I honestly chalked it up to the dealer giving me a minimal amount of coolant when new. I topped it off, everything seemed fine.

  • At 6000 miles as I noticed the first drop of coolant on my garage floor after a ride. I noticed it was coming from the weep hole, but had not yet researched the issue so just assumed it was a normal vent of some kind. I thought maybe when I topped off at 2000 that it didn't like it and burped it out or something. Reservoir is showing exactly mid-point between max and min at this time. So again, I didn't really think much of it.

  • Then after a ride this weekend I noticed a couple more drops on the floor, and a small but much more obvious drip from the weep hole. I clean it, and it doesn't drip while sitting. Only after a ride.

After a lot of reading on the issue I plan to call my nearest dealer (4 hours away) and discuss scheduling the bike in. I wouldn't mind tackling it myself because the cost is less of an issue to me compared to the stress of leaving my bike at a shop for what is no doubt going to be a long time. But that challenge aside, a couple of questions...

  • I understand this is likely a seal on the pump shaft or housing that is leaking coolant. How exactly is the coolant getting from the leak to the weep hole? Is there some kind of void space between the pump housing and the outer wall of the sump? My bike is too new for me to jump in and remove the sump just to peek, especially if it might be going to the dealer for this anyway. I'm just really curious what is going on inside. What is the path of travel for the leak from source to weep hole? I've seen the weep hole assembly on BMW's parts diagram, but it's just not making sense to me.

  • How bad is this issue? I would assume my bike is grounded until I can get the issue resolved. But I always assume the worst! Since I don't know enough about exactly how the leaking fluid can travel I am assuming the worst risk is the possibility of cross-contaminating oil and coolant. I've read many many posts of different generations of models of BMW and other bikes, even cars, having this issue for decades. In most cases, people are continuing to ride/drive their vehicle until a repair can be scheduled. Can I ride my bike before this is fixed or is it better to park it? It's clearly not a big leak, because it's only a few drops after the ride and then nothing else comes out. But...it's still a leak so I'm concerned about making things worse.​
Guess I'm looking for "what would you do" type of feedback, in addition to a better understanding of the internal workings that result in the leak. Thanks!
 
Discussion starter · #4 ·
Moving forward, ANY coolant leak is a safety concern. Especially if the leak is right in front of the rear tire. Coolant is very slippery.

The oil water pump has o rings that give up the ghost. Having delt with this 2x so far and getting to put my hands on the problem I can see where the failure is/was.

When you get it back check the oil frequently and change it if it looks cloudy. There may be residual from the service.
One thing I'm after is the detail behind your second paragraph... if you've done the work yourself I'd be real interested to know more about what that looks like.
 
Discussion starter · #7 ·
Dealer does the work under warranty!
True. But...

I have severe anxiety about working with dealer service departments. Among many other experiences, mostly with cars (tech going on joy rides, techs blowing a built motor, techs scratch/denting/damaging vehicles), I can refer you to my page where I document an experience I had with my local Ducati/BMW dealer (www.motojuliasucks.com).

But my main concern is that it's all likely to go like this...

  1. Load bike on the trailer, drive 5 hours to the dealer (since I can no longer use above mentioned local dealer), drop off bike = time and fuel cost
  2. Despite what I've told them is wrong, they will want to diagnose themselves. Then they report to BMW. Who may or may not grant warranty because my bike is modified, even though this just means they don't understand US warranty laws since we're protected from that kind of nonsense. Either way, it's PITA territory.
  3. Eventually, a part is ordered
  4. If I'm very very lucky, no other problems will be created while the bike is with dealer until I get it back

There may be weeks that pass between each step. And weeks that pass before they get the part. And then weeks that pass before they actually get around to installing it.

Very recently my (new, out of state) dealer told me I needed to bring my bike in for the timing chain tensioner recall, and that I would need to leave the bike with them and they had no idea how long it would be before they could get to it. Couple weeks they implied.

Meanwhile, I ordered the recall part and installed it myself and lost only a few days.

The more I learn about this repair, the simpler it looks. Still learning though, before I dive in.
 
Discussion starter · #9 ·
Might regret it, but I'm diving in and doing this myself. Ordered the parts. At the end of the day, the parts are cheaper than the travel expenses I would incur to get the bike there and back on the trailer, all without knowing if they are going to fight me on warranty anyway. Service manual is on the way too, so at least I'll have the procedure and torque specs. Should be fun, and I'll learn more about the bike. And if it happens again, it's just another repair rather than "another trip to the dealer".
 
Discussion starter · #11 ·
Well, if it means anything at this point when my bike was in for service per my post above, I had Akra headers on the bike. BMW went ahead and covered the oil/water pump repair.

Where are you getting the service manual? No dealer is able to order the CD anymore and I'm sure any left over stock any dealer may have are already sold.
Trying my luck with one of the manuals sold on ebay. Will report back to say if those are legit or not. But I will apparently need to find an old external DVD drove and blow the dust off of it 😆
 
Discussion starter · #12 ·
Update, picked up a K67 service manual from ebay. It's a perfect PDF version of the manual.

The procedure to replace this pump is cake. Haven't done it yet, so that's easy to say! But honestly it looks pretty straightforward. All parts ordered, I'm looking forward to it! And definitely looking forward to not being without my bike for weeks/months during some of our best riding weather (in the US south..it's only "kinda cool" here rn)
 
Discussion starter · #19 ·
Ya, it doesn't look too bad. Remove exhaust, remove sump, and there it should be. Manual only calls for renewing the gaskets and the shaft nut that secures the sprocket. I should be able to reuse the rest, if I have to order more screws or that "assembly" then I will.

Edit: and I also have a custom exhaust (AR) so it should be just slipping out the rear section rather than full removal for me as well.
 
Discussion starter · #21 · (Edited)
This page lists all the possible parts, but according to the service manual not all need to be renewed.

The service manual states only to renew the pump, the sprocket nut for the pump, and all the o-rings. I am taking the additional steps of renewing all the bolts that hold the pump and the bolts that secure the sump (they are the same), but I think that is unnecessary for most. I am not renewing any other parts or bolts at this time as the bike only has 6000 miles on it.
 
Discussion starter · #23 ·
Minor update. Finally accrued all parts (my fault it took so long, figuring out which Orings to replace, but I'm making a recipe list for you future DIYers).

Began the repair this weekend, and was kicking ass. Thought I might even finish.

I took the new pump out of the little grease bag (I had only inspected that it arrived thus far, but hadn't yet removed it from the bag). That's when I noticed that BMW sent me a mangled piece of ****.

Also including a few pics from behind the sump, in case anyone was curious what is going on in there. More to come. Just waiting to hear back from BMW on a replacement pump for the replacement pump.

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Discussion starter · #29 ·
Quick update...

The work is complete, bike is back together, and knock on wood so far so good after the first weekend of riding. No more dripping. I even installed my new white coolant pipes during the process. Even cooler with the fairings on because they only just peek out a little.
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The "how-to" for this is in progress. Most folks, for now at least, will be getting a dealer to warranty this repair so it might be a while before it is really useful. Taking my time with it, and might make a video too.

But in the meantime I wanted to share this as food for thought, all of which only just confirms what @bennymx has said before about this coolant leak.


This is the pump
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Turn it over and you have these little ports, the larger port on the left is the oil pickup, the o-ring port on the right is the oil "out" to the motor.
The smaller one with the little hole/channel inside is what I'm calling the "coolant leak detection drain port" because that is the only reason it is there.
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The oil pickup snout and drain port is a very sophisticated plastic shape, top side of which connects to the intake and leak detection ports. Bottom side is the oil pickup snout and the leak detection port output (the part you can see when you look under your bike).
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It looks like this when all connected
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Reason for the post is: WTF BMW.

WTF.

Why all the trouble to engineer this failure detection system rather than FIX THE PROBLEM with the pump. Is it a problem with the brand of pump? Is it a problem with the manufacturing or installation? It's likely a problem with how the shaft and seals are assembled but you can't even tear the pump down to observe the source of the leak.

That's why they just replace the whole thing.

It's a dumb and disappointing thing to see tbh.

I'm not looking forward to doing this again, but I bet I will be given the community failure reports. There is no official recall (afaik) probably because there is no solution atm. At least it'll go more quickly next time.
 
Discussion starter · #33 ·
But without looking inside at the internals, you don't know for sure....right?
I mean, it still had a leak detection port. Externally it was identical.

I need 'no leak detection necessary' kind of robustness. I would have been very happy to find out I needed to buy a new oil pickup assembly because they got rid of that port!
 
Discussion starter · #36 ·
i’m facing the same problem on my bike now and i don’t know where to start. did you happen to record a video of the process? is this something i would be able to do? biggest procedure i’ve done on a motorcycle is replace the spark plugs
It's not difficult, but it takes time and patience, and the right tools and the service manual.

I've been swamped with work and life and haven't sat down to do a writeup. But...

If you can remove and reinstall your exhaust,
If you can change your oil,
If you can drain and refill your coolant,
If you can drop a clean gasket bead,
If you can handle the patience and time it takes to remove the sump,
If you have a digital torque wrench that measures down to 3Nm,
Then the rest is pretty simple.
 
Discussion starter · #39 ·
hmm never removed exhaust from headers but doesn’t seem too hard. i also don’t know what a gasket bead is :/ i just wish there was a video somewhere that i could use for guidance but it doesn’t look like anyone has posted a video on this
I have video clips of the parts that would need explaining in a video. Really, it's only how you need to twist the pump out of the sump once it is unbolted, and then twist the new one back in because it doesn't just pop out in a simple way. But it's not that difficult. Most difficult part really was just getting the sump unstuck.

A clean bead means using the right type of liquid gasket, and a tiny perfectly even amount down the middle of a perfectly clean sump cover lip surface, and mating that cleanly to a perfectly clean engine block surface.

If you reference the service manual I linked in my previous comment and follow through the steps you can judge for yourself if you can handle it. If you think you want to tackle it I'd be happy to talk you through it (or maybe I'll get off my butt and make the writeup...but honestly 90% of any writeup is just going to be stringing service manual steps together).
 
Discussion starter · #41 ·
ok i took a look at the manual. it looks like i remove headers and unfasten all the bolts for the oil pan and drop the pan. from there I have access to the pump. what parts need to be replaced though? am i removing all parts of the pump system including the chain shown in the manual? if you have videos of what to do at this point it would help a ton

I'll make a parts list for you tomorrow when I'm back at my PC. I need that for the writeup anyway.

You unbolt the sump, then the hard part is breaking the bond of the old sump gasket and popping it off but I have a trick for that.

You remove the nut from the gear, remove the gear, let the chain hang, then unbolt and twist the pump out of the sump. Reinstall is the reverse of removal.

I'll follow up tomorrow.
 
Discussion starter · #42 · (Edited)
So, just briefly...
From this link it is easier to say what you don't need. You DON'T need #s 3, 5, 6, 7, 8, 9, 10, 11.
The pump will arrive with the pinion attached. That sucks because it has to removed during installation of the pump. Make sure you renew the nut as it is a one-time use, theoretically.

Nuts and bolts and o-rings that you order may be different colors or styles from the ones that come off of the bike. That's ok. As long as you match the part number to the piece and the size is correct then you are good.

From this link you DO need #s 4 & 7. This line is removed from the block to get access to a sump bolt, or at least makes everything WAY easier when it is out of the way. You remove bolt #6 in this pic just to loosen up the line prior to popping it out of the block, but you only need to replace bolt #4 according to the service manual. Use thread locker on #6 per the manual.

From this link you DO need fourteen (14) #4, as well as #s 3 & 5 (or use your preferred oil pan liquid gasket suitable for the S1000RR).

Aside from stray items like if you have the OEM exhaust, maybe you want to replace the gaskets or something, that's out of scope and for you to identify.

But I think that's about it. Oil, oil filter, coolant, tools, etc. Take lots of pics along the way for reference. It all goes together like Legos. Just have to take your time.
 
Discussion starter · #44 ·
Also worth mentioning there are slightly used pumps available on ebay for way less than new. Of course that's a risk, but also we're working around a design flaw so it's like a box of chocolates whether it's new and not leaking or used and not leaking (yet). Unless of course they have improved the internal design of newer units but there's no way to tell.