I had my Coolant flushed in November and have driven about 150 miles since over the winter. The coolant reservoir is nearly empty and I want to refill it. The coolant in the tank is yellowish or perhaps a little green could also be slightly blue, it actually looks closer to clear than any color. I purchased Blue antifreeze from the local auto parts store which was clearly marked for all MINIs and is clearly blue.

Is it a problem that the antifreeze does not match?
Is it bad enough that I should have the shop re-flush the system?
And a final question: How full should I fill the reservoir? Half way?

The R52 now has 21,500 miles and I am trying to maintain it in as perfect shape as possible.

 

The MAX level in the tank is up to the seam in the middle:
https://www.ecstuning.com/b-genuine-...p/17137529273/

You could probably just dump a little bit of water in there to bring the level up and be fine.

 

check to see if the a/f you bought is pre-diluted or concentrate ... most a/f at parts stores is sold both ways . . .




the solution should be 50% a/f cut with distilled water, pre-mix will be at this concentration IME ..... the small amount of 100% you'd add won't throw things off very much but why waste money?

a/f is a case where MORE is NOT better ...... TOO much / too high a concentration won't perform as well as the proper mix . . .

folks sometimes make the mistake of filling their car with 100% a/f thinking this is better and then find themselves with cooling system issues . . .

and YES, I've used plain old Prestone to top off my MINIs as needed since 2002 - mine and folks I help out - ZERO problems with a combined mileage approaching 500,000 miles (multiple cars) ... color don't matter and will change as the coolant 'ages'. What you don't want to see is any sign of OIL or foaming.

 

I think the easiest and pretty safe thing to do would be to add some distilled water, if it is just a part of the tank, it's a pretty negligible amount compared to the entire cooling system which holds about 1.5 gallons.

I would probably use an antifreeze tester, or turkey baster to pull some of the coolant out of the tank and get a better look at it.
I have one of these. https://www.google.com/aclk?sa=L&ai=...gQIARBB&adurl=

I don't know how accurate it is, but it's a good way to pull some coolant out and look at it.

I ran green universal prestone coolant in my first R53 and honestly didn't have any problems. mixing coolants can get a little risky because some of them will precipitate a solid when combined.

I currently run blue coolant that I buy from the dealer because I figure it's the safest way to go and it's not terribly expensive.

 

Always check when the system is stone cold. You will find that, if you fill the reservoir too much, it will "disappear". Don't worry. Let it get to a level that it doesn't get any lower. That will be about 1 to 1-1/2 inches above the bottom of the reservoir. I use a wood stick with a ballpoint pen mark at the proper level to check it periodically.