Blue coolant is now slowly turning reddish.

[Flyingdutchman]

Hi all, my 2005 bmw e91 325i has always seen blue bmw/mb 325.0 blue coolant. Ive replaced it 60k miles ago.

Because i will preventively replace some parts i already got new basf g48 coolant.

However i decided to look how the current coolant is looking, just a preventive check to see if there is no oil mix or whatever.
However now i discovered that the coolant is slowly turning pale reddish.

I am 100% sure this car has always had blue coolant and in my 100k miles of ownership it has always been clearblue coolant when peaking into the expansion tank.

Anybody got a clue whats going on? Is this a sign that its deteriorating over time? I dont think its an atf mix up. Atf on these cars is yellowish.

I think this must have happened in the last 15k miles or so.

One picture of the tank, one picture is of the new mb325.0 coolant that i have also previously used.

As i said i can see that people think i mixed up red coolant in the system but i can guarantee that is not the case. I also think that if thay might have happened it would just turn up blackish with the blue green and red mix.

 

[Passport1]

Looks like your blue coolant has morphed into Dex-Col;

 

[ripcord]

Has this been in a shop at some point where they may have added a different coolant?

 

[Flyingdutchman]

Has this been in a shop at some point where they may have added a different coolant?

No i have always done all the maintanance myself. I have found a picture of what it looked like 15k miles ago.
In the meantime i replaced the radiator but then again filled it with it with blue coolant.

Guess i will have to see it will stay clear blue with the new oem spec basf glysantin g48. If nothing leaks/mixes it should stay clear i guess.

 

[Freischneider]

I have no idea but I'm interested to know what happened.

 

[FowVay]

Who has borrowed your glycomat? I'd rinse it thoroughly with clean water and take another sample. Maybe someone else used it since you last did and didn't flush it like they're supposed to.

 

[slacktide_bitog]

Is it some kind of color change wear indicator they put in the coolant?

 

[Trav]

You didn't happen to use a water wetter type product did you?

 

[Flyingdutchman]

No i am always very keen on keping it like factory spec and dont use any additives or leakstoppers. Because this car has an electric waterpump its important that it only uses clean factory spec coolant.

 

[Freischneider]

I'd flush the system and send some of the old cooling out for an analysis.

 

[Marcozi]

This is why I always buy coolant from the dealer.

 

[kschachn]

This is why I always buy coolant from the dealer.

I can’t tell from the way his post is worded but it almost sounds as though that’s what he has in the system now.

 

[Flyingdutchman]

Yes heres a picture of when i changed the radiator 5k miles ago.
Not the best pic but i think you can clearly see it was still blue back then

 

[akbrian]

I think the original MB325.0 is pretty close to G-05. Looking through the Zerex spec sheets for their "G" spec products shows G-05 as being 325.0 complaint, whereas the other are for other MB325.x standards. If that is the case, then G-48 is going to be quite a bit different. Have you mixed the two coolants? I see that G-48 has 2-EHA, whereas G-05 doesn't.

 

[Craig in Canada]

G-48 is "correct" for BMW applications, so I don't think OP is doing the wrong thing by using G48 if they cannot get genuine BMW coolant. No idea what's going on, never seen that happen in any of my bimmers over the years. Were it mine, and observing the 'keep it original' habit of OP, I would see if I could source genuine coolant from a dealer or reputable online source (not ebay, not amazon) and drain and refill (not flush). I do wonder if some well meaning person didn't top it up. BMW expansion tanks are flow-through, however. The "top up" fluid wouldn't stay in the expansion tank as it would with some vehicles, it would mix in throughout. It would take a lot of "top up" to change the entire volume to pink.

EDIT: 325.5 seems to be pink. I know you specifically said you choose 325.0. Are we sure there's no chance that someone did you a "favour"?
https://www.europaparts.com/engine-coolant-q1030005.html

 

[doitmyself]

Yes heres a picture of when i changed the radiator 5k miles ago.
Not the best pic but i think you can clearly see it was still blue back then

Any chance it has something to do with the new radiator installation? Metallurgy?

 

[Rand]

Looks like it got topped up at a quick lube or somewhere. Any chance someone added washer fluid to wrong cap? I know in the ram they look the same.
(although that looks like straight dexcool)

 

[2EHA]

I think the original MB325.0 is pretty close to G-05. Looking through the Zerex spec sheets for their "G" spec products shows G-05 as being 325.0 complaint, whereas the other are for other MB325.x standards. If that is the case, then G-48 is going to be quite a bit different. Have you mixed the two coolants? I see that G-48 has 2-EHA, whereas G-05 doesn't.

g48 replaced g05 a long time ago. it is a drop in replacement for all iat and early european hoats

 

[Jethro_Bob]

How old is the coolant, all the bottle I've seen online says five years, generally factory fill life is double the time for subsequent service. Assuming you changed it the 10 year mark (if not sooner) you might be at least 2 years past due meaning you are starting to see rust from the iron block.

 

[DuckRyder]

I wonder if the new radiator had some sort of anti corrosive or other residual from assembly in it.

Is the car an automatic and does the transmission fluid look OK?