[toxik]

I haven't been able to get a concrete answer from anyone on this, and I've read/heard both sides of the isle. My car is at about 55k, a 2017 model, I was considering doing a full coolant flush in the fall when I do my next oil change. My coolant has been topped up many times during my ownership, so i'm sure a good portion of it is not 7 years old.

Some people say doing a 60k interval coolant flush is generally good for your car. Others say unless the coolant itself looks bad, or tests below the pH threshold, you shouldn't touch it. I like to do preventative maintenance, I don't necessarily want to constantly test my coolant pH levels, I think keeping new coolant in the system is preferable to marginally passable coolant. I've even seen people say that due to this being a pressurized complex system, it's better to not touch it at all.

Anyways, at the end of the day I don't want to waste money doing something that's not needed or recommended, potentially causing more issues than needed.

Let me know what you guys think.

[Cytoplasm0671]

Spoke with a pro mechanic a while back who said new coolant every 60K was best practice. Just me two cents.

[lpaulodt]

I would recommend doing it. Use a vacuum fill tool and run both low and high temp bleeding procedures afterwards.

[PeterWT]

Mine is also a 2017 w/ ~60K mi. and my coolant has also been topped off many times.
I intend to have the cooling system flushed in the fall, with my 60K oil change. 6 years / 60K mi. is a reasonable service life for coolant.
I had my transmission fluid/filter/pan done at 5 years / 50K mi. Again, reasonable service life.
Relatively cheap insurance if you intend to keep the car.

[toxik]

Originally Posted by PeterWT

Mine is also a 2017 w/ ~60K mi. and my coolant has also been topped off many times.
I intend to have the cooling system flushed in the fall, with my 60K oil change. 6 years / 60K mi. is a reasonable service life for coolant.
I had my transmission fluid/filter/pan done at 5 years / 50K mi. Again, reasonable service life.
Relatively cheap insurance if you intend to keep the car.

same actually with my drivetrain fluids at 50k, had em done last fall. looks like we’re on the same maintenance timeline

[nosam1g]

its real easy to DIY. 2 Hoses one connecting to rad , and other heat exchanger. Let them both drain out.. get Distilled water , and bmw coolant ,, fill back up half water / coolant. Look up bleeding procedure , very simple maintenance or you can go to a shop and pay 200$ lol

[toxik]

Originally Posted by nosam1g

its real easy to DIY. 2 Hoses one connecting to rad , and other heat exchanger. Let them both drain out.. get Distilled water , and bmw coolant ,, fill back up half water / coolant. Look up bleeding procedure , very simple maintenance or you can go to a shop and pay 200$ lol

i diy as many things as i can on my car, but i can’t do any type of fluid changes in my garage, i live in a condo building. either way, that’s not what i was asking in this thread…

[Cytoplasm0671]

A coolant flush is one of the only services I would pay for because, unlike motor or transmission oil or even brake fluid, doing coolant flushes yourself often involves it spilling copiously on your hands or the ground. No thanks.

[toxik]

Originally Posted by Cytoplasm0671

A coolant flush is one of the only services I would pay for because, unlike motor or transmission oil or even brake fluid, doing coolant flushes yourself often involves it spilling copiously on your hands or the ground. No thanks.

yep agreed, me and Runner340 were talking about it last week and he said the same thing. I have car friends who let me come to their house and borrow their quickjacks for under the car DIYs, but I would never ask someone to do a coolant flush at their house and make a huge mess everywhere. maybe 20 years ago when I was a broke teen and paying a shop was a major hit to my wallet.

[AspektUSA]

Do it.

Valvoline, who is the OEM, recommends 5yrs/100k mi.

[kern417]

I vote skip, but that's just me personally. You are not going to get all of the coolant out of both systems anyway. A good chunk of it is trapped at the bottom of the radiator and we don't have a proper drain point that is low in the system.

[PeterWT]

Originally Posted by kern417

I vote skip, but that's just me personally. You are not going to get all of the coolant out of both systems anyway. A good chunk of it is trapped at the bottom of the radiator and we don't have a proper drain point that is low in the system.

Honest question because I've never done a coolant service on these cars.
Wouldn't the dealer or a well equipped & educated shop do a 'flush and fill', not just a drain and fill?

[B58 parts]

Originally Posted by Cytoplasm0671

A coolant flush is one of the only services I would pay for because, unlike motor or transmission oil or even brake fluid, doing coolant flushes yourself often involves it spilling copiously on your hands or the ground. No thanks.

Yeah, it does suck. Especially since there is no drain valve, you pop the hose and it just goes everywhere, from both ends. Then the drip hits on other parts and goes even more everywhere.

Last time I used my recycle bin, it was almost big enough. A big sheet of cardboard on the floor, nitrile gloves, hat. A 6'x6' pan would be good. How about a drain valve, like Honda has. Despite all that, it still was all over the floor, and all over me by the end.

My water pump is leaking. That will be 3 times touching coolant in 9 months. Punctured front rad in October, hose blew off out of nowhere during casual driving late March, and now leaking pump/replace entire cooling system.

Siphoning what you can out of the tank and leaving it factory sealed as long as possible could be the way. Plastic junk.

[Jnat]

i just had it done along with a lot of other things including a water pump and i'm at 59k... i'll do it every 60k... makes sense to me.

[lens]

I had the dealer do mine though they didn't do the air to water intercooler reservoir.

It cost about 260$ for the drain and fill (including parts and labour)

Surprisingly cheap for dealer stuff.

[kern417]

Originally Posted by PeterWT

Honest question because I've never done a coolant service on these cars.
Wouldn't the dealer or a well equipped & educated shop do a 'flush and fill', not just a drain and fill?

Not in my experience.

They don't even design our systems to be fully drained anymore. Unless you have contamination I struggle with this one, but it's not something that'll necessarily hurt. As long as you bleed it properly.

[johnung]

If you change your coolant, research first and also change any known problems in the cooling system. For example the N55 plastic Mickey Mouse fitting is known to break so I replaced it with an aluminum upgraded fitting along with a new hose. Also the top coolant return line has a plastic fitting that eventually breaks. It can’t be upgraded so I just have it on my list of regular maintenance items to proactively replace before they break.

Every engine has items like these that are worth proactive replacement .

[Cytoplasm0671]

Two proactive replacements for my 340i manual transmission are replacing the cheap plastic clutch fork pivot pin with a brass version and replacing the soft metal rotor set screws with stainless steel versions.

[Wires]

I'm with Kern417 on this one. In a previous lifetime, cast iron blocks used to rust and start to contaminate the fluid. With aluminum and plastic, I struggle with what actual goes wrong over time (coupled with it's impossible to replace all of it).

[toxik]

Originally Posted by Wires

I'm with Kern417 on this one. In a previous lifetime, cast iron blocks used to rust and start to contaminate the fluid. With aluminum and plastic, I struggle with what actual goes wrong over time (coupled with it's impossible to replace all of it).

because of the b58 coolant loss issue, and the whole white residue around the cap, a part of me wants to try to get back closer to a 50/50 mix. i know it’s not necessary, but there are other reasons besides corossion that makes me want to do a flush and fill just as a reset.

this thread did basically confirm my notion from reaearch i’ve done, there’s no good answer to this dilemma. it seems just as a matter of opinion.

[Wires]

Originally Posted by toxik

because of the b58 coolant loss issue, and the whole white residue around the cap, a part of me wants to try to get back closer to a 50/50 mix. i know it’s not necessary, but there are other reasons besides corossion that makes me want to do a flush and fill just as a reset.

this thread did basically confirm my notion from reaearch i’ve done, there’s no good answer to this dilemma. it seems just as a matter of opinion.

Ahhh I get where you are coming from. You can get a antifreeze tester to confirm what the concentration is (to see if it's really needed). On older vehicles you could just pull the radiator cap, extract a bunch and replace with pure coolant or water and let it mix. Not sure if there is a clean way with the newer sealed systems.

The car does burp and suck coolant from the expansion tank, so that should be very close to what the rest of the system sees from a mixture standpoint. I'd just wouldn't add straight coolant or water to that tank.

[toxik]

Originally Posted by Wires

Ahhh I get where you are coming from. You can get a antifreeze tester to confirm what the concentration is (to see if it's really needed). On older vehicles you could just pull the radiator cap, extract a bunch and replace with pure coolant or water and let it mix. Not sure if there is a clean way with the newer sealed systems.

The car does burp and suck coolant from the expansion tank, so that should be very close to what the rest of the system sees from a mixture standpoint. I'd just wouldn't add straight coolant or water to that tank.

yeah exactly, first time I got the low coolant warning, I was far from home and could only add distilled water, then I added coolant when I got home. Far from a measured 50/50 mix, just a guestimate. A lot of people seem to think evaporated coolant means you should just add water, since that's what evaporated... but that doesn't sound like exact science to me either.