(100%) Water Pump Replacement (DIY)

[SaNGRia]

Hello folks,

I have 2017 F85 with 34K miles one it. I recently had a strange issue and just upset with it. I was pushing hard about 7 minutes on highway. And suddenly got the warning on the dash saying that Engine Coolant Low. I didnt see the warning about 10 minutes after the actual coolant warning came to the dash , i noticed the warning on my video recording afterwards. And drove even harder in that 10 minutes. I noticed the warning closer to my house since the windows was rolled down with a messy smell all around.

Luckily Engine temperature never exceeded 120C (Canadian Cluster). I parked the car on a ramp in my garage and shut the car off. Came out and it was leaking bad under the engine area. Most probably auxiliary pump was still on and pushing all the fluid out.

Then tried to diagnose the issue. The space is so tight. It was one of the most annoying diagnostic i ever had. I then bought an endoscopy camera to see all the tight areas. I then even made a smoke test using my good old hookah. And 99% the issue coming from water pump seals. All the hoses and connectors are fine. No crack nothing. Radiator area is bone dry.

Reservoir is completely empty at the moment. The thing is as soon as i pour alittle bit fluid in it, it leaks almost instantly from that area.

While i was under the car checking all the places, i noticed that the radiator made in China which was a huge disappointment. I am totally okay with the car assembled in the US but the parts being from China made me think that E series Ms are the last REAL DEAL in my book!

This car has been driven in Canada and NY so i can only think of being in harsh weather condition what made this seal to go bad and somehow driving in high rpm, rip off the seal and create a big gap so it is pouring like i pour the water from the top of the engine!

I am really disappointed with the situation and i am waiting parts to arrive so i can start the procedure.

It is a very tight space. Even it looks not big of a deal, still gonna take some time to get to the bottom of it!

If any of you experienced something like that or did a Water Pump replacement , welcomed to share their experiences.

I will start the DIY with some info and go from there.

The reason i am saying 99% the seal is leaking is, the leak definitely not coming from the top of the engine. So turbo hoses are fine. leak is not coming from the hoses since i have put paper towels to see is there any drop or anything but Nada!

I looked that area on some forum pictures, some s63 ebay Ads and some TIS documentation, If the hoses are not leaking around that area, only thing left is either Water pump shaft or seal. I checked the shaft area, it was also bone dry. So my prediction on this issue mostly water pump seal.

Btw, Warranty expired 3 months ago!

Here is the leak right after parked, It was a mess. FLuid was all over. Did a good cleaning :

Testing with a little bit of fluid :

Here is the endoscopy of the F85 with Fluid and Smoke Test (First F85 smoking Hookah in the world) :

Here is some info :



Parts for the seal replacement listed as :

2 Gasket 11-51-7-549-445
4 Water Pump Assembly O-Ring 11-51-7-572-792
7 Torx Bolt 889520 07-12-9-905-939
8 Water Pump Assembly Bolt 07-12-9-905-938
9 Water Pump Assembly Bolt 07-12-9-905-569
This last 2 bolt is a guess. One going to fit where the O ring goes. M6 but the length is not mentioned so i got 25 and 30. But seems like one with the washer will work since i see a washer around on the original bolt!
Isa Screw With Washer 889520 07-12-9-905-537
Screw T99V00SM06 11-14-1-460-752

I actually decided to get a whole new water pump with new thermostat so i dont need to deal with unexpected leak after the installation. It is already a labor intense job, not worth to give a try with just the seal replacement imo.

Water Pump : 11-53-7-843-738
Thermostat : 11-53-7-586-885
Thermostat bolts : 07-12-9-905-569

Belt Removal :




Removing the Water pump :



Installing the Water pump :



Torque Values :




Some Pictures :





The camera i used for the diagnose can be found here

[Sophisticated Redneck]

You mentioned it all seems to be coming out the expansion tank. The tanks have always been a weak spot on the E70, same tank used on the F85. I would loosen up it's screws and use your borescope to check out th connections underneath, the level sensor is held in by a plastic clip that just rotates to lock it in. Verify it and the coolant tube underneath are in good condition. You will need a set of automobile picks to release the retaining clip on the b coolant tube if you need to replace.

If the coolant tank checks out I would then grab the TIS download offered on eBay, these SUV's are way to complicated without it. I would then pull the fan so you have some room to see what is going on. Coolant leaks can be misleading as the water follows the tubes down from one path to another. BMW usually makes the fans easy to remove, haven't done it yet on the F85 but on the E70, you can remove it in about 5 minutes after you do it once and I bet the F85 is very similar.

[SaNGRia]

I actually found the exact place where its leaking today. Tank and hoses are completely fine. When i did the Hookah Test Without blowing the smoke, u can hear the air leak around the water pump area but here is the video of water pump shaft failure :

But i am super happy to pin point the issue. I was questioning what if it wasnt the water pump seal. So luckily i caught the issue and will be replacing both water pump and thermostat at the same time.

Over all that endoscopy camera was the best investment so far!

[Sophisticated Redneck]

Originally Posted by SaNGRia

I actually found the exact place where its leaking today. Tank and hoses are completely fine. When i did the Hookah Test Without blowing the smoke, u can hear the air leak around the water pump area but here is the video of water pump shaft failure :

But i am super happy to pin point the issue. I was questioning what if it wasnt the water pump seal. So luckily i caught the issue and will be replacing both water pump and thermostat at the same time.

Over all that endoscopy camera was the best investment so far!

Interesting the water pump shaft seal failed, how many miles? As for the Thermostat, are you going to replace with stock or upgrade to the 90C unit? I have been happy with the Hamburg 90c thermostat in my E70, dropped temps from 230ish to 200-205F and have 40k miles on it so far with zero issues. I know some guys who have installed the same thermostat in their F90's and love it too.

[ekological]

Glad you found the issue! But man, at 34k miles and 3-4 years old, that corrosion looks scary! People laugh when I still have my '02 M5 beater to drive in the winter. It wasn't worth it to me to drive my new to me '16 X5M all year long starting two years ago when I purchased it.

Originally Posted by SaNGRia

[m3fuz]

Damn - that sucks it went off at 34K miles, but I’m glad you got it taken care.

Also, thanks for the link to the endoscope - I’ve been looking for one of those for a while.

[SaNGRia]

Talk to me about it. I have a 08 E93 M3. Forget about the snow but Never driven in rain It is literally in Brandnew shape. So seeing a younger M with this condition was killing me. One of the first thing i did when i got the car was going under and doing heavy duty simple green spray with metal brushes. Luckily it is under 12 years rust plan. If i feel like i can replace the whole panel underneath! But yeah this shouldnt be rusted like this in such a young car. This shows me quality is dropped on the newer vehicles impo!

Originally Posted by ekological

Glad you found the issue! But man, at 34k miles and 3-4 years old, that corrosion looks scary! People laugh when I still have my '02 M5 beater to drive in the winter. It wasn't worth it to me to drive my new to me '16 X5M all year long starting two years ago when I purchased it.

[SaNGRia]

My pleasure buddy. Yeah this was one of the best investment. I cant tell how much it helped me to find the issue! Enjoy!

But yeah even tho i have used rpm limitter couple of times and even tho car is driven on harsh weather condition it shouldnt be failing that soon. Bad luck i guesss!

Originally Posted by m3fuz

Damn - that sucks it went off at 34K miles, but I’m glad you got it taken care.

Also, thanks for the link to the endoscope - I’ve been looking for one of those for a while.

[Yuille36]

Originally Posted by SaNGRia

My pleasure buddy. Yeah this was one of the best investment. I cant tell how much it helped me to find the issue! Enjoy!

But yeah even tho i have used rpm limitter couple of times and even tho car is driven on harsh weather condition it shouldnt be failing that soon. Bad luck i guesss!

It sad to see the amount of rust under the vehicle, I would have thought that the underbody was treated with a corrosion inhibitor. I personally never let road salt sit on my vehicles for more that 3 days, before having it removed

[SaNGRia]

Originally Posted by Yuille36

It sad to see the amount of rust under the vehicle, I would have thought that the underbody was treated with a corrosion inhibitor. I personally never let road salt sit on my vehicles for more that 3 days, before having it removed

Completely agreed. As obsessive as i am , it's really not fun to see it. That's why u need to buy a Floridan car But unfortunately there was non exist the mileage and the options i want in the entire US other than what i found during my time.

I will most probably do ice blasting on entire engine and undercarriage

[SaNGRia]

Originally Posted by Sophisticated Redneck

Interesting the water pump shaft seal failed, how many miles? As for the Thermostat, are you going to replace with stock or upgrade to the 90C unit? I have been happy with the Hamburg 90c thermostat in my E70, dropped temps from 230ish to 200-205F and have 40k miles on it so far with zero issues. I know some guys who have installed the same thermostat in their F90's and love it too.

I didnt know there is such an upgrade exist. I just ordered the oem one. I was driving with the oem thermostat since day one it goes little bit over the quarter if i drive hard so i was super happy with the cooling system actually comparing to my s65

[Yuille36]

Originally Posted by SaNGRia

Completely agreed. As obsessive as i am , it's really not fun to see it. That's why u need to buy a Floridan car But unfortunately there was non exist the mileage and the options i want in the entire US other than what i found during my time.

I will most probably do ice blasting on entire engine and undercarriage

Yes, if the option exist buy a southern vehicle, as they are free of the rust belt. My vehicle was purchased in Wilmington, NC. 😁 Dry ice blasting will definitely get rid of the rust, while not causing any damage to the underbody. I'm nice completed your vehicle will look as it just rolled out the assembly line 😁

[SaNGRia]

Originally Posted by Yuille36

Yes, if the option exist buy a southern vehicle, as they are free of the rust belt. My vehicle was purchased in Wilmington, NC. 😁 Dry ice blasting will definitely get rid of the rust, while not causing any damage to the underbody. I'm nice completed your vehicle will look as it just rolled out the assembly line 😁

Thats the goal Only the thing is the black undercarriage metal under the engine is painted. When you do ice blasting it will remove the rust and will show the metal so it will need to paint again.

[SaNGRia]

Ice Blasting wont work for me since they are asking $2750 for the process. SO i decided to DIY as usual. I am treating the rust with vinegar and got out like 95% of the nasty rust so far. Later on i will be wet sanding and will repaint the trim after cleaning up everything. I cant believe how much rust i got out.

Be honest the coat they used rusted. Metal looks just fine behind it!

[SaNGRia]

How the heck this can happen?

[640ijims]

What are we looking at in the circle? Casting issue that finally failed?

[SaNGRia]

Originally Posted by 640ijims

What are we looking at in the circle? Casting issue that finally failed?

Casting doesnt fail the way it is pictured. It looks like a cut not a crack! So yeah u re looking at a failed water pump casting.

My theory is the shaft inside of the pump failed and did this cut somehow. I will try to remove the pulley to see what it looks like inside.

I concluded this as a manufacturer failure since it has gone bad so early!

[640ijims]

Wow

[Klienfeld303]

Originally Posted by Sophisticated Redneck

Interesting the water pump shaft seal failed, how many miles? As for the Thermostat, are you going to replace with stock or upgrade to the 90C unit? I have been happy with the Hamburg 90c thermostat in my E70, dropped temps from 230ish to 200-205F and have 40k miles on it so far with zero issues. I know some guys who have installed the same thermostat in their F90's and love it too.

Red you have a link for this thermo? Thanks for this information and thanks for the OG post. A lot of solid info there. Suck it happened but at least you have forum family to help. 💪🏽

[Sophisticated Redneck]

Originally Posted by Klienfeld303

Red you have a link for this thermo? Thanks for this information and thanks for the OG post. A lot of solid info there. Suck it happened but at least you have forum family to help. 💪🏽

Sure thing, link below. I've got about 40k miles on it now and noticed cruising temps to start right around 206F and when I slap it into sport mode and step on it, will drop down to 195 after few min. This is because it does have a heating element built into the wax engine so the DME can open the thermostat even more for addition cooling when needed. On the F85, I would assume in M mode you will see the lowest temps. Now it doesn't list the F85 but the F85 still uses the same thermostat part number as the E70 and it does list the F90 and there are several forums who are using it on the F10 M5 & F90 without issue so it appears an oversight on the application list.

https://www.ecstuning.com/b-hamburg-...37586885-90c~/

[SaNGRia]

Alright guys, Today i was able to replace all the parts since Ebay seller and FCP Euro overnight them and i got all the parts and installed.

I will be honest, this job was harder than replacing the RBs on E9x swear. As easy as it looks, it is really pain in the butt to remove and install the pump in place since it is very tricky to align the 3 main hose.

Beside the alignment, the bolts under the pump is super hard to put in place. If i did not have that Endoscopy camera, it would take about 4 hours to just put this bolts. Space is so tight plus bolts are really in very awkward places. I couldnt even fit my torque wrench in that tight place to torque them correctly. I just made them tight by hand. Probably over torqued them but idc , i am exhausted already but the car works without a leak. And problem solved.

In the meantime, i have found something might help all of us in the future. N63 engine has different part no for the pump and it is about $200-$240. The part no for that one is 11517548263 And when u looked at realoem, it says it fits on F15 50i which has the same engine 4.4 TT we have. So i couldnt figure out what can be different on that pump but they look identical. If that pump works for us, then no need to pay 450-640 for the M Part No.

[RomeoXantos]

Originally Posted by SaNGRia

Alright guys, Today i was able to replace all the parts since Ebay seller and FCP Euro overnight them and i got all the parts and installed.

I will be honest, this job was harder than replacing the RBs on E9x swear. As easy as it looks, it is really pain in the butt to remove and install the pump in place since it is very tricky to align the 3 main hose.

Beside the alignment, the bolts under the pump is super hard to put in place. If i did not have that Endoscopy camera, it would take about 4 hours to just put this bolts. Space is so tight plus bolts are really in very awkward places. I couldnt even fit my torque wrench in that tight place to torque them correctly. I just made them tight by hand. Probably over torqued them but idc , i am exhausted already but the car works without a leak. And problem solved.

In the meantime, i have found something might help all of us in the future. N63 engine has different part no for the pump and it is about $200-$240. The part no for that one is 11517548263 And when u looked at realoem, it says it fits on F15 50i which has the same engine 4.4 TT we have. So i couldnt figure out what can be different on that pump but they look identical. If that pump works for us, then no need to pay 450-640 for the M Part No.

Can anyone confirm if this pump works?