[afo818]

After many changes I’ve been good so far I think the new part fixed the problem. Been about 5k miles or so

[Alberta]

I brought my car in for service at my dealership and spoke to the sales manager about the issue regarding coolant fluid leaking.

After checking the tank, he saw some residue of coolant.

I've decided to replace the tank and the cap by the new part number 17137889450.

I hope I'll be fine.

[bimmerbeast9]

Originally Posted by afo818

Very odd they don't have a remedy for it. I changed it first at 28k miles (2 months ago) now at 29.5 and need a new one again lol

your second one got hairline cracked during handling getting it to you to get replaced.

get a coating put on 3rd one? rhino lining? or such

[NoMods]

tagged

[NoMods]

So I confirmed now again and I have the dreaded leak, it’s very small as it’s all white residue and no liquid but I will be scheduling for service tomorrow.

[hunter8793]

2022 6k miles. I'm gonna clean it off and see what happens.

[hunter8793]

photo

[AHall]

Originally Posted by hunter8793

photo

That is a interesting place for the dried coolant. When these tanks fail is it the tank or the cap? I do not believe there are any tank seams in the area but f the dried coolant in your picture. Have you ever opened your tank?

In the picture above your post there is residue at the seams and in the channel from the cap.

[NoMods]

https://www.instagram.com/p/CtwX-2AK...XDinbtnpY6k6xQ

looks like someone made or prototyped a piece for under the expansion tank

[pbonsalb]

Interesting, but I can’t figure out how it works. Is it a drip catcher? How much does it hold? Or does it have a drain off to some nearby area of the engine bay where no harm will be caused by leaking coolant?

I replaced my tank preventatively, put heat reflective tape under it, put heat reflective tape under the upper sheetmetal cover, and blanketed my turbos to reduce heat. And I open my hood pretty regularly to check on things.

[NoMods]

Originally Posted by pbonsalb

Interesting, but I can’t figure out how it works. Is it a drip catcher? How much does it hold? Or does it have a drain off to some nearby area of the engine bay where no harm will be caused by leaking coolant?

I replaced my tank preventatively, put heat reflective tape under it, put heat reflective tape under the upper sheetmetal cover, and blanketed my turbos to reduce heat. And I open my hood pretty regularly to check on things.

did you have to do anything special when you swapped out the tank, did it have to be pressurized or anything? was it just loosening the bolts holding the tank, disconnecting the hoses and sensor?

[PetroM5]

Originally Posted by pbonsalb

Interesting, but I can’t figure out how it works. Is it a drip catcher? How much does it hold? Or does it have a drain off to some nearby area of the engine bay where no harm will be caused by leaking coolant?

I replaced my tank preventatively, put heat reflective tape under it, put heat reflective tape under the upper sheetmetal cover, and blanketed my turbos to reduce heat. And I open my hood pretty regularly to check on things.

From what I can tell from the pictures I believe it catches and diverts the fluid away from the plugs and coils.

This is their post translated.

The BMW M5 F90 has a tradition - to corrode 🤓

fuel injectors with antifreeze A chain of events leads to it, each of which is not fatal individually.

- For the sake of layout, the tank was placed above the engine - The tank itself was not equipped with a spout to drain the liquid to hell
- The motor operates at high pressure in the coolant
circuit - The motor is powerful, it emits a lot of heat
- and therefore, after vigorous races, it spits a little through the valve. And sometimes the tank flows at the seams

All this would be NOT important if it were not for two BUT:
- from the tank flows directly into the well of the nozzle - antifreeze turns the plastic body of the nozzle into a sponge, and then destroys the copper conductor

And the magic of phased direct injection begins to limp fiercely
- the machine runs unevenly on XX, troit and falls into error over time.

We have our own tradition - to go to the problem.
So our engineering department has designed and stamped parts that are worthy of standing there from the factory.

Meet the king-trough, drop-receiver-savior!

It will divert trouble from your injectors. And from the wallet - extra expenses 👌

#levelperformance #bmw #m5f90

[pbonsalb]

Originally Posted by armoredsaint

did you have to do anything special when you swapped out the tank, did it have to be pressurized or anything? was it just loosening the bolts holding the tank, disconnecting the hoses and sensor?

You want to avoid having the coolant in the tank leak out onto the injectors when you disconnect the hoses. It is not possible to siphon much coolant out of the tank. I suppose you could drain down the cooling system but that is a pain. You also want to avoid having any coolant remaining in the hoses leak out and flow into the injectors or coils. Other than being careful not to make a mess, there is nothing special in the process.

[pbonsalb]

Originally Posted by PetroM5

From what I can tell from the pictures I believe it catches and diverts the fluid away from the plugs and coils.

This is their post translated.

Thanks. That makes sense. This might be a good part to have. Of course you also don’t want to hide a problem from view, but you could probably still smell a leak or see drips on your garage floor. I don’t think I will buy one, but it is something to consider for those who don’t check under their hood often.

[hunter8793]

That seems like a stupid bandaid "fix" that fixes half the problem.

I ordered a new tank and I'll take it to a local engineer and see if he can make something out of aluminum for us.

[AHall]

Originally Posted by hunter8793

That seems like a stupid bandaid "fix" that fixes half the problem.

I ordered a new tank and I'll take it to a local engineer and see if he can make something out of aluminum for us.

Hopefully you are able to get an aluminum tank that works fabricated. I tried to find a aluminum solution a year or so ago. The problem I ran into is the sensor. For some reason reason BMW designed the tank with a permanently molded in sensor instead of a sensor with threads you could replace if it failed. So part of the solution would be finding a sensor that works with the car and can be integrated into the tank.

I did consider some sort of shield made out of metal or the use of heat reflecting tape similar to what pbonsalb has done. The tape could prevent failure and the shield similar to the plastic one mentioned above is intended to limit damage of a tank failure. For now I just monitor the tank for leaks frequently. In 2 plus years I have no issues but I do not drive the car hard at all. I am not sure if that matters.

[windtendo]

Originally Posted by AHall

That is a interesting place for the dried coolant. When these tanks fail is it the tank or the cap? I do not believe there are any tank seams in the area but f the dried coolant in your picture. Have you ever opened your tank?

In the picture above your post there is residue at the seams and in the channel from the cap.

On my 2019, the coolant kept leaking from the cap. The cap would loosen on it's own and the coolant would spew out in all directions.

[AHall]

Originally Posted by windtendo

On my 2019, the coolant kept leaking from the cap. The cap would loosen on it's own and the coolant would spew out in all directions.

So did you just replace the cap and did that solve the problem?

[windtendo]

Originally Posted by AHall

So did you just replace the cap and did that solve the problem?

This was a few years back, but I believe the coolant tank was replaced under warranty with the dealership.

[pbonsalb]

For the aluminum tank, a level sensor should not be a problem. I think it is just a 2 wire on/off type sensor that grounds when triggered to complete a warning light or ECU check engine light. It’s not like a variable resistance coolant temperature sensor that has to have the right resistance to match the scale on a gauge.

Maybe one can be found that would fit the factory harness end from another BMW or other car but that could be hard to find. Splicing a new harness end might be required.

[NoMods]

the dealer just pressure tested my expansion tank and said zero drop in pressure, told me the white residue is from the cap that is designed to release pressure and fluid will come out. i am still somewhat skeptical, but at least there's a record of my check. they did replace my brake fluid a few months early when I asked if they could so I don't have to stop by in the fall.

[pbonsalb]

Maybe these cars operate at higher pressure than last BMWs that have 200kpa caps and never show white residue. 29psi is really high cooling system pressure in my opinion, but I am not an engine builder or professional mechanic.