[BimBimM2]

Hi all,

I have only 12k original miles on my M240i xdrive convertible.

I have had three oil changes at the BMW dealership

First at 1200 miles, Second at 5000 miles, and third at 10,000

I opened up the hood the other day and saw this near the coolant reservoir. Pic is attached. What is this?

[aerobod]

Looks like the cooling system pressure cap is either not sealing fully or the pressure relief valve in the cap has opened (coolant above the MAX mark can cause that). I would check the level is between MIN and MAX when the engine is cool, reduce level if above MAX, probably best to replace the cap if below MIN. The white residue is just the remains of evaporated coolant.

[BimBimM2]

Originally Posted by aerobod

Looks like the cooling system pressure cap is either not sealing fully or the pressure relief valve in the cap has opened (coolant above the MAX mark can cause that). I would check the level is between MIN and MAX when the engine is cool, reduce level if above MAX, probably best to replace the cap if below MIN. The white residue is just the remains of evaporated coolant.

Thanks Aerobod. Take a look at these pictures.

I feel like the coolant is low

[aerobod]

Very slightly low, the cap may be OK and the threads and seals may just need cleaning up, as there seems to be dirt in there. I would get a damp rag and try and clean any dirt and residue away and check the rubber seals on the centre barrel inside the cap. Best to do a 50/50 mix of BMW blue coolant with distilled water, needs about 0.2 of a litre to bring it to MAX (although just distilled water won't dilute the coolant too much). I always moisten the seals with a drop of coolant before re-inserting the cap. It is also worth checking the charge cooling reservoir under the other cap to see that it is between MIN & MAX.

Both caps should fully closed when they have a positive click when the yellow arrows are aligned.

[BimBimM2]

Originally Posted by aerobod

Very slightly low, the cap may be OK and the threads and seals may just need cleaning up, as there seems to be dirt in there. I would get a damp rag and try and clean any dirt and residue away and check the rubber seals on the centre barrel inside the cap. Best to do a 50/50 mix of BMW blue coolant with distilled water, needs about 0.2 of a litre to bring it to MAX (although just distilled water won't dilute the coolant too much). I always moisten the seals with a drop of coolant before re-inserting the cap. It is also worth checking the charge cooling reservoir under the other cap to see that it is between MIN & MAX.

Both caps should fully closed when they have a positive click when the yellow arrows are aligned.

Okay thank you! First you had me looking into Caterhams and now helping me out with this. You are the best!

I got this coolant from the local dealership. Does this need to be diluted? Instructions don't mention any dilution. This bigger container does say 50:50 dilution.

What do you think?

[dradernh]

Originally Posted by BimBimM2

Does this need to be diluted? Instructions don't mention any dilution. This bigger container does say 50:50 dilution.

There's been no change. This is the same coolant BMW has been selling for years, and it's diluted 50:50 with distilled water.

––––––––––––––––––––––––––––––––––––––

FWIW, in answer to an owner's query the following was Mike Miller's advice on where to maintain coolant levels in a March, 2019 Roundel Tech Talk column (my underlining):



Given the issues owners have had with BMW cooling systems' plastic components over the years, I've chosen to follow Mike's advice here.

Miller addresses this in a bit more detail on p. 24 of his Lifetime Maintenance Schedule, the subject being premature failures due to excessive pressure w/in the closed system.

[BimBimM2]

Originally Posted by dradernh

There's been no change. This is the same coolant BMW has been selling for years, and it's diluted 50:50 with distilled water.

––––––––––––––––––––––––––––––––––––––

FWIW, in answer to an owner's query the following was Mike Miller's advice on where to maintain coolant levels in a March, 2019 Roundel Tech Talk column (my underlining):



Given the issues owners have had with BMW cooling systems' plastic components over the years, I've chosen to follow Mike's advice here.

Miller addresses this in a bit more detail on p. 24 of his Lifetime Maintenance Schedule, the subject being premature failures due to excessive pressure w/in the closed system.

Alright so gauging from my pictures above, if I were to follow Mike's advice, should I let it be? And really, I'd follow Mike's advice as well. I will clean up the seal and whatnot as per Aerobod's advice

[dradernh]

Originally Posted by BimBimM2

Alright so gauging from my pictures above, if I were to follow Mike's advice, should I let it be? And really, I'd follow Mike's advice as well. I will clean up the seal and whatnot as per Aerobod's advice

Sorry, I can't tell where the level is from the photos.

What I can share with you is that I was keeping mine at MAX and it was overflowing just a bit during track sessions. I then looked to Miller for advice and saw what he'd written in his LMS. I lowered mine to MIN, it's been fine on the track since I did that, and it's remained ~MIN each time I've checked it since that time.

Like many other forum members, I did have to add coolant one time after I first bought the car. That's when I raised it to MAX. I have no idea what the level was when I drove the car away from the dealer. Aren't our cars fun!

[BimBimM2]

Originally Posted by dradernh

Sorry, I can't tell where the level is from the photos.

What I can share with you is that I was keeping mine at MAX and it was overflowing just a bit during track sessions. I then looked to Miller for advice and saw what he'd written in his LMS. I lowered mine to MIN, it's been fine on the track since I did that, and it's remained ~MIN each time I've checked it since that time.

Like many other forum members, I did have to add coolant one time after I first bought the car. That's when I raised it to MAX. I have no idea what the level was when I drove the car away from the dealer. Aren't our cars fun!

Thank you gents! Due to both you and Aerobod I learnt a lot today. Let me refill a little above the MIN mark and clean and seal it.

Can I pre-mix the coolant solution in a bottle with a 50:50 ratio? I read that you must pour the coolant in after pouring in distilled water.

[aerobod]

Originally Posted by BimBimM2

Thank you gents! Due to both you and Aerobod I learnt a lot today. Let me refill a little above the MIN mark and clean and seal it.

Can I pre-mix the coolant solution in a bottle with a 50:50 ratio? I read that you must pour the coolant in after pouring in distilled water.

I just mix 50:50 in a small glass container and pour in. Normally just 100ml / 3 fluid ounces to bring the level up 1cm or so.

[dradernh]

Originally Posted by aerobod

I just mix 50:50 in a small glass container and pour in. Normally just 100ml / 3 fluid ounces to bring the level up 1cm or so.

I mixed mine ahead of time, too. I used a few fluid ounces and still have more of the mix if I ever need it again.

[BimBimM2]

Originally Posted by dradernh

I mixed mine ahead of time, too. I used a few fluid ounces and still have more of the mix if I ever need it again.

Do you have a copy of Mike's updated maintenance schedule for F-series cars? For some reason I can only find it for E-series cars

[morphomeman]

As I have said repeatedly on this forum, if the car is still under warranty, take it to the dealer for the experts to look at, instead of trying to fix the problem yourself. The techs will know if the cap is faulty and if so, they will replace it at no cost to you. With luck, problem solved and you will be able to sleep peacefully. Well, except for the coronavirus nightmares.

[dradernh]

Originally Posted by BimBimM2

Do you have a copy of Mike's updated maintenance schedule for F-series cars? For some reason I can only find it for E-series cars

All I know and have of Mike's are the two docs listed in post #10 of this thread: https://www.2addicts.com/forums/show....php?t=1713767.

FWIW, when queried on the subject as recently as last year, he's commented in "Tech Talk" that he's had no reason to update the LMS since 2013.

Mike accepts and (generally) quickly answers specific questions from club members, so that's always an option if you've run into one of the many issues not covered in those two docs. Beyond his own wealth of knowledge, Mike can call on people from around the country when helping members with their cars.

[BimBimM2]

Originally Posted by dradernh

All I know and have of Mike's are the two docs listed in post #10 of this thread: https://www.2addicts.com/forums/showthread.php?t=1713767.

FWIW, when queried on the subject as recently as last year, he's commented in "Tech Talk" that he's had no reason to update the LMS since 2013.

Mike accepts and (generally) quickly answers specific questions from club members, so that's always an option if you've run into one of the many issues not covered in those two docs. Beyond his own wealth of knowledge, Mike can call on people from around the country when helping members with their cars.

Wonderful! Much appreciated sir! I am a BMWCCA member so I will reach out to Mike. Whole thing was such a fun read!

[keylime503]

Coolant leak from the main (not secondary) coolant tank is incredibly common on B59 engines new from the factory. So you're not alone. I've had to top off my coolant on my M240i probably 4-5 times. Each time I've asked the dealer to look at it and do a pressure test, they come back to me with a "idk everything looks fine to me but we filled it up for ya!". I've never actually had a warning light come on. These were all from manually checking on my coolant levels before track days.

[BimBimM2]

Originally Posted by aerobod

I just mix 50:50 in a small glass container and pour in. Normally just 100ml / 3 fluid ounces to bring the level up 1cm or so.

Hey Aerobod, so I followed yours and DraderNH's excellent advice and have the coolant in the large tank filled perfectly tipping above the minimum line. Life is good.

I found a similar residue on the smaller reservoir as well, decided to open that up and lo and behold, that reservoir is above the max line!! No wonder the coolant has been running out of the caps (these caps are designed to let out excess coolant).

Check the pictures! (I took a few angled shots to get a sense of where the coolant level is as opposed to the max mark).

Please note that the car has not been driven for a good 8 hours at this point.

Point is, how can I "scoop" out the excess coolant from that reservoir? Should I take it to BMW? Because those monkeys "topped off the fluids" last time I had service done.

[dradernh]

Originally Posted by BimBimM2

Point is, how can I "scoop" out the excess coolant from that reservoir?

Have a turkey baster handy?

[BimBimM2]

Originally Posted by dradernh

Have a turkey baster handy?

I thought about that; using a 10 ml syringe. I should try that. Sucking the coolant out won't be a problem, I guess I was a bit worried if there is any potential damage I should be concerned about.

[BimBimM2]

Originally Posted by dradernh

Have a turkey baster handy?

Pulled out excess coolant and it is... brown? Is this normal? See attached pic

P.s. viscosity is as fluid as water

[dradernh]

Originally Posted by BimBimM2

Pulled out excess coolant and it is... brown? Is this normal? See attached pic

P.s. viscosity is as fluid as water

I would expect it to be blue, but...

[BimBimM2]

Originally Posted by dradernh

I would expect it to be blue, but...

Yeah I wouldn't think there is a rust issue... the car is a 2018 with only 12k original miles. Doesn't seem like there is an oil leak; that would change the viscosity. I mean given if it started life as blue/green then it would take a shit load of oil leaks to turn it into THAT brown, and with that much brown-ness I would be looking at a thicker liquid. This is thin as water, yet so brown.

I have a feeling that when they "topped off fluids" they used some orange coolant.