Coolant leak from grommet/plug underside of thermostat casing

[OzbimmerXR]

Hi All

Wondering if anyone has had trouble with the grommet/plug on the bottom of the thermostat housing leaking, mine is minimal more of a weep and leaves dried drip marks on the engine case next to it and the exhaust, coolant expansion tank was down to minimum line so probably less than 100mls over 2-3 month period.  Bike has 73,000 klms on the clock.  I wasn't able to find any parts diagrams that showed this underside section.

[Mareng1]

That is the waterpump seal leakage.

It won't self-heal - so get it off to a BMW dealer for a new one.

It is a well-documented failure (unless you try for a goodwill gesture).

There is, apparently an American modification (a different pump) that takes away the issue - but it isn't cheap.

[OzbimmerXR]

Thanks Mareng 1

Have done some more research after your reply and yes this is a common problem, and apparently it can re occur after repair even multiple times.  Starting to sound like the cam chain tensioner issue.  I bought a manual one of those from the US and problem fixed.  You don't happen to have any more details on that US repair option I could chase up by any chance?  Thanks again.

[Mareng1]

Here is an ebay link to one - you'll find the manufacturer from that.

https://www.ebay.co.uk/itm/275226661564?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&customid=CjwKCAjw0a-SBhBkEiwApljU0jvB-KbDQUzEcI9JbcM4xQqjysVDn2ijUxAz-hJb3hFe92-aLurdNRoCIusQAvD_BwE

or

https://www.hsbkracing.com/parts-and-apparel/bmw/s-1000-rr/engine/jetprime-bmw-s1000rr-xr-r-cnc-enlarged-water-pump-2009-to-2018/

[OzbimmerXR]

  Just picked myself up off the floor, you were right again that certainly isn't cheap think I will see what the BM one's are here, thanks again.

[OzbimmerXR]

Just checked Jetprime direct, they have agents in Oz even worse $750.00 AUD, maybe time for a new bike???

[OzbimmerXR]

You can buy a gasket set but I wonder whether it is the impeller shaft gasket that is the problem which doesn't come in the kit???

[Mareng1]

I've not heard of anything short of pump renewal as being the answer, I'm afraid.

I had mine done at BMW dealer, but can't remember the cost.  Comes with a 2yr warranty though (on the parts, at least)

Labour was £70, parts were around £250 - +VAT 

[Antares]

If I was you and BMW didn't offer to repair it for free or at least heavily discounted, I'd look into doing this

Or get someone to TIG weld the crack, I don't see anything that it would touch so you don't even need to worry about cleaning the weld up, maybe for balance, but that's all I can think of.

I would say just put some silicone sealant around the grommet to stop it from leaking, but the issue seems to be coolant getting behind the waterpump, but from what I can see, there is nothing separating the oil and coolant in that area, and coolant in your oil is a big no-no even if it's a little bit.

[smithy]

Originally Posted by OzbimmerXR

Hi All

Wondering if anyone has had trouble with the grommet/plug on the bottom of the thermostat housing leaking, mine is minimal more of a weep and leaves dried drip marks on the engine case next to it and the exhaust, coolant expansion tank was down to minimum line so probably less than 100mls over 2-3 month period.  Bike has 73,000 klms on the clock.  I wasn't able to find any parts diagrams that showed this underside section.

Thermostat housing..?? Thermostat lives next to the starter motor at the top/rear of the engine, very difficult to get at....your picture is of the water pump, easy to remove & replace. The gasket set only has the gasket and O-ring, no mechanical seal or bearing/impeller. You can't buy the bearing, impeller or seal separately. You can do as Antares mentions in the attached video but you'll need your own lathe and access to all the correct materials, tooling etc..

https://www.realoem.com/bmw/enUS/showparts?id=0D03-EUR-02-2017-K49-BMW-S_1000_XR_0D03,_0D13_&diagId=11_4487

I've had one of these pumps apart before...You'll destroy the bearing, impeller & seal pulling it apart. This has been an ongoing issue on the Gen-1 engine since the first RR was released in 2010.. and it was never really resolved until the Gen-2 was released.

I bought a second hand 2012 RR water pump off fleabay for $30, I got rid of the silly BMW blue silicate coolant, (which is rather abrasive and tends to destroy the internal carbon seal faces), I filled the system with good quality Australian made Nulon coolant and it hasn't leaked since...45k km later and it's still good.

Smithy.