[Inquisitor]

The car is 6 years old now and the dealer in Southern California is charging 190 for the coolant flush. The other maintenance is free and covered by the package. Should I flush the coolant or leave it in the system for the duration of ownership

[RMachuca3d]

200$ isnt much, get it done.

[Billfitz]

If it ain't broken don't fix it. I'd only consider it if it looked contaminated, and then I'd do it myself for twenty bucks.

[bavarianride]

Try to do a litmus test, if pH is 7 (neutral) or below(alkaline) then it may be worth changing out the coolant.

Local indies charge $150, at times dealers run coolant + brake fluid combo for $250.

[Slick_FThirty]

I did mine at 8 years. BMW Coolant is recommended to change at least every 4 years according to my service advisor at the dealership. Apparently, it's the interval that BMW has established.

It isn't a difficult DIY, if you can do it in your circumstances. It would only be the coolant and distilled water that you would need to buy, in addition to other basic tools.

I would suggest doing it.

[AspektUSA]

I think blue coolant is 7yrs, and green coolant is 2yrs?

2018 vehicles were filled with the green stuff.

[capt_slow]

Originally Posted by Slick_FThirty

BMW Coolant is recommended to change at least every 4 years according to my service advisor at the dealership. Apparently, it's the interval that BMW has established.

It was every 4 years, but now it's been changed to lifetime if you got CBS. However, 4 years is the consensus in the BMW community for preventative maintenance.

I was going to change it out last December, but ended up deferring it. The PH levels were still normal after 4 years.

[chowser51]

Check your coolant expansion hose and connections while you’re at it.
Mine blew at 2-3 years (60+k miles though)

[Psi5]

Originally Posted by capt_slow

It was every 4 years, but now it's been changed to lifetime if you got CBS. However, 4 years is the consensus in the BMW community for preventative maintenance.

BMW's "lifetime" fill just means "leave it there until the part fails." If you plan on keeping the car past warranty, I recommend following BMWCCA Mike Miller's "Old School" maintenance schedule which recommends coolant be replaced every two years.

[Billfitz]

Replace coolant every two years? That's nuts. We never changed coolant that often even when engine blocks were still made of cast iron that rusted. Coolant is a condition based item. If it's in good condition there's no need to change it. The BMW recommendation is very conservative, in no small part because dealerships charge $200 for $20 of coolant and an hour labor. If it tests good it is good. You've just got to test it, but that should be part of your regular personal maintenance routine anyway.

[bavarianride]

Originally Posted by Psi5

BMW's "lifetime" fill just means "leave it there until the part fails." If you plan on keeping the car past warranty, I recommend following BMWCCA Mike Miller's "Old School" maintenance schedule which recommends coolant be replaced every two years.

Most automakers recommend 10 years/100k lifetime coolant change interval(then 50k afterwards), so Mike Millers seems to be too old school in this regard.

[auburnf30x]

Originally Posted by bavarianride

Most automakers recommend 10 years/100k lifetime coolant change interval(then 50k afterwards), so Mike Millers seems to be too old school in this regard.

That’s what I follow. Unless contaminated, I don’t worry about it until the 10 year/100k mark. And even then, it’s not necessarily indicated since the fluid doesn’t really degrade or perform any mechanical function. Mostly just for peace of mind.

[Psi5]

Originally Posted by bavarianride

Most automakers recommend 10 years/100k lifetime coolant change interval(then 50k afterwards), so Mike Millers seems to be too old school in this regard.

Perhaps, but $20 (or even $150) every few years seems reasonable and given Mike's extensive knowledge and experience, and his dedication to BMWCCA and its members, I defer to his recommendations when servicing my car.

I followed his advice on my E39 and E90 and both made it well past 150k with zero issues wrt to his recommended intervals. The cars certainly had problems but none were fluid or maintenance-based.

[Billfitz]

Originally Posted by auburnf30x

the fluid doesn’t really degrade or perform any mechanical function.

Coolant can get too acidic, or to be more accurate, not alkaline enough, which reduces its anti-rust properties. That could take four years, but it could take twenty. It's easy enough to test. Reading this thread reminded me to test mine today, taking all of five minutes. Mine's fine, at six years.

If I went by BMW's time based recommendation for brake fluid flush I'd have done that twice by now. Since I had the hood up anyway I measured the water content of my brake fluid today. It was zero.

[bavarianride]

Originally Posted by Psi5

Perhaps, but $20 (or even $150) every few years seems reasonable and given Mike's extensive knowledge and experience, and his dedication to BMWCCA and its members, I defer to his recommendations when servicing my car.

I followed his advice on my E39 and E90 and both made it well past 150k with zero issues wrt to his recommended intervals. The cars certainly had problems but none were fluid or maintenance-based.

I followed BMW's recommended 4-year coolant change interval for E39 with zero issue when sold@100k miles.

The F30 was sold at 8+ years and 80k+ miles, with one coolant change@6 years/60k miles, since the dealer only refreshed 1L of coolant while completing a thermostat recall(and coolant approached pH of 7 at 6-yr mark).

[thebmw]

How do you test the coolant at home (not at dealership)?

[Billfitz]

Use a pH test strip for acidity, an antifreeze tester for freeze point. The acceptable pH range is 7.5 to 11. You can get a supply of strips and an antifreeze tester for ten to fifteen bucks. Both should last you through at least two cars.

[bavarianride]

I have this antifreezer tester bought@Amazon 20 yrs ago that I used on all cars:

https://www.amazon.com/Prestone-AF-1...3012357&sr=8-2

[tjlees]

what I love about recommended it's either an average or worst case.

Testing the anti-freeze and brake fluid has saved me a small fortune over years.

its not lifetime, but anti-freeze or brake fluid testing has ever resulted in changing every two years.

BTW it worth testing immediately after it's changed - sometimes its not done properly ;-)

Wish there was an easy way of testing the lifetime transmission oil - usage makes so much difference to service intervals.

[bavarianride]

Originally Posted by tjlees

Wish there was an easy way of testing the lifetime transmission oil - usage makes so much difference to service intervals.

Correct, ZF recommends 150000 km of change interval for normal usage, but it would be great to easy access to test the fluid, esp. the ZF fluid change process is not simple drain and fill.

[tjlees]

Originally Posted by bavarianride

Correct, ZF recommends 150000 km of change interval for normal usage, but it would be great to easy access to test the fluid, esp. the ZF fluid change process is not simple drain and fill.

My towing usage could impact this but I have no real hard recommendation - other than every 30,000 miles which would be costly

[bavarianride]

Originally Posted by tjlees

My towing usage could impact this but I have no real hard recommendation - other than every 30,000 miles which would be costly

Yeah towing(together with spirited driving and autobahn speeds) can raise operating temperature, which is cited by ZF as main factor to shorten service interval.