[Zanity]

Ok, now that I got the engine oil done and sorted, I'm wondering what's the coolant flush interval for my 2015 428i (N20) ? I googled and searched, and came up with nothing again. owners manual mentions nothing either, my last E92 335i had "lifetime" coolant, but after 7 years, I can see a bit of rust in the reservoir already. Anyone have info or experience on this ? My mechanic friend says it's 10 years life for the blue BMW OEM coolant, they reduced it to 5 years now to increase coolant sales and I shouldn't worry about it (my car is still around 31,000 km / 19,000 miles). I use the car for daily to the office at 9km (6 miles) away, I don't race or drive it hard, mostly in ECO PRO mode. I like to hear you guys opinion on this, much thanks guys !

[IraHayes]

Originally Posted by Zanity

Ok, now that I got the engine oil done and sorted, I'm wondering what's the coolant flush interval for my 2015 428i (N20) ? I googled and searched, and came up with nothing again. owners manual mentions nothing either, my last E92 335i had "lifetime" coolant, but after 7 years, I can see a bit of rust in the reservoir already. Anyone have info or experience on this ? My mechanic friend says it's 10 years life for the blue BMW OEM coolant, they reduced it to 5 years now to increase coolant sales and I shouldn't worry about it (my car is still around 31,000 km / 19,000 miles). I use the car for daily to the office at 9km (6 miles) away, I don't race or drive it hard, mostly in ECO PRO mode. I like to hear you guys opinion on this, much thanks guys !

Probably a little overkill on my part, but every car I've ever owned, I replace the coolant every 2 years regardless of whether it's lifetime or not. Just be sure to use the correct coolant, otherwise it can start to gel and clog your cooling system. I had this happen to me once, but fortunately I caught it before it was too late and was able to flush it all out of the system.

I will look in my Bentley manual later on tonight when I get home and see if they specify an interval of any kind, but I believe BMW recommends every 4 years; 3 years for M cars.

[Zanity]

ok, thx, plz let me know

[bavarianride]

Originally Posted by IraHayes

I will look in my Bentley manual later on tonight when I get home and see if they specify an interval of any kind, but I believe BMW recommends every 4 years; 3 years for M cars.

There is no written coolant change interval from BMW(not in service and warranty manual). SAs usually say 100k miles for BMW blue coolant.

[Zanity]

I read somewhere theres a coolant tester stick kit you can buy to test the coolant quality, is there such a thing? BMW sure doesn't make it easy for us to do our own maintenance on the cars.

[TurboLove]

Originally Posted by IraHayes

Probably a little overkill on my part, but every car I've ever owned, I replace the coolant every 2 years regardless of whether it's lifetime or not. Just be sure to use the correct coolant, otherwise it can start to gel and clog your cooling system. I had this happen to me once, but fortunately I caught it before it was to late and was able to flush it all out of the system.

I will look in my Bentley manual later on tonight when I get home and see if they specify an interval of any kind, but I believe BMW recommends every 4 years; 3 years for M cars.

Lol send me a Bentley please

[Billfitz]

Originally Posted by Zanity

I can see a bit of rust in the reservoir

Change it.

[Zanity]

Originally Posted by Billfitz

Change it.

dude, not sure if you even read what I wrote, that was my last E92 335i, that car is long sold

[Billfitz]

Sorry, it didn't occur to me that you were writing about two different cars, let alone that one of them you don't even have anymore. Back when I used to keep cars more than 6 or 7 years I'd change mine at 60,000 miles or when I saw it had rust or dirt in it, whichever came first.

[IraHayes]

Originally Posted by Zanity

ok, thx, plz let me know

Well, according to the Bentley manual, “BMW specifies the engine coolant, manual transmission fluid, differential fluid and transfer case fluid are lifetime fluids.” I think we all know better than to listen to that nonsense.

BMW TIS states four years for standard cars, three for M on coolant system servicing. This is probably a more realistic interval to follow.

[Zanity]

I see, thanks, the lifetime is definitely BS. But 4 years seems quite short too, I mean Hyundai even says their coolant is good for 10 years and they have way longer factory warranty than BMW to take the risk of saying that. I guess just like the air filter, I just have to keep an eye on it at every engine oil change. I'll probably do the coolant flush around 6 or 7 year mark.

[bavarianride]

Originally Posted by Zanity

I'll probably do the coolant flush around 6 or 7 year mark.

Mine was changed in 6 years. The coolant color cue turned from greenish blue to pale light blue. The freeze/boil points are the same, but the pH dropped from 8.5 to 7(neutral), so my coolant's anti-corrosion property is wearing out.

[Zanity]

do you remember how many mileage you had when you did it at the 6 year mark?

[bavarianride]

Originally Posted by Zanity

do you remember how many mileage you had when you did it at the 6 year mark?

52k miles.

FYI there was a thermostat recall@32k miles, and the coolant was supposed to be flushed.

Unfortunately BMWNA was too cheap to pay for coolant flush, and the SIB instructed tech to reuse old coolant, plus 1L of topoff, or else my coolant should be still tip-top shape@52k.

[bavarianride]

Originally Posted by Zanity

I read somewhere theres a coolant tester stick kit you can buy to test the coolant quality, is there such a thing? BMW sure doesn't make it easy for us to do our own maintenance on the cars.

This may work.

https://www.amazon.com/Cool-Trak-311...s=coolant+test

Also this tool can quickly check boil/freeze, plus the color cue of the coolant.

https://www.amazon.com/ABN-Deluxe-An...ant+hydrometer

[Zanity]

Originally Posted by bavarianride

52k miles.

FYI there was a thermostat recall@32k miles, and the coolant was supposed to be flushed.

Unfortunately BMWNA was too cheap to pay for coolant flush, and the SIB instructed tech to reuse old coolant, plus 1L of topoff, or else my coolant should be still tip-top shape@52k.

I can't believe they did that, coolant is not expensive, they probably took the coolant out and dumped it in some dirty oil tank, then dumped it back in the car, it's not like they gave a sh*t. I checked my car for recall when I bought it and there was nothing outstanding. I guess I'll just check the coolant with that stick kit in a couple years

[bavarianride]

Originally Posted by Zanity

I can't believe they did that, coolant is not expensive, they probably took the coolant out and dumped it in some dirty oil tank, then dumped it back in the car, it's not like they gave a sh*t. I checked my car for recall when I bought it and there was nothing outstanding. I guess I'll just check the coolant with that stick kit in a couple years

The irony is, BMW's own TIS for coolant drain and fill procedure explicitly advises not reusing old coolants, but BMWNA still went ahead to instruct techs to do just that for thermostat recall job. Oh well.