Checking with folks about their experience with MINI radiator fluid... My 2005 Cooper S with JCW had somewhat dirty radiator fluid (appeared to have some tiny black bits in overflow reservoir) which I told my mini dealership about, and they gladly changed the fluid... They said possibly during the JCW install, some head gasket may have gotten into the water jacket of engine... The car doesn't over heat, and the chrono pack temp guage points straight up as expected.... The car runs beautifully... and survived a 2 day driving school... No bits in the fluid now but....

My question is that even post fluid change, the blue radiator fluid appears to have a weird presention, kinda like the bluesness of the fluid is a bit milky but not dirty, almost like the fluid has some blue specks or the fluid broke apart... The car runs great, doesn't lose coolant, but being a bit obsessive about fluid cleanliness, I thought I would change out the radiator fluid with new bmw radiator fluid and distilled water... I have about 4 k on car now, and don't want to take half a day off of work to go to the dealership, etc... Also, thought the engine water jacket may have had some stuff in it too....

Curious how other's radiator fluid looks, and this I think may be normal... specifically, how does folks with 2005 models fluid look like.. but I appreciate anyone/any model years chiming in...

Thanks, thanks and thanks again!

 

mine started out like an aqua-green color.... now a filthy brown.

 

I do not know what is going in in your cars, but I have had several cars that took multiple flushings before the coolant started looking clean.

I've always thought it was residue from the manufacturing process getting flushed out of all the nooks an crannies inside the motor.

 

I thought that flushing may be the answer... and since the dealer did it once, I think I'll do it again, possibly take out the expansion tank, and clean that too... Appreciate the responses...

thanks again

 

I'd like to know how they flushed it. If you just remove the lower radiator hose like the service manual says, only the stuff in the radiator and expansion tank comes out. The engine is still holding over 1/2 the coolant. Is there an engine block drain to get the rest out?

 

Yes, I am aware of this issue... and you are correct...

I think the only way to really flush it, at least by me at home, is to buy bmw or mini coolant, mix with distilled water, and change the fluid, run car, bleed, etc, and finish job...

Then do it all over again...

I don't think the mini has way to empty the block of coolant, unfortunately. My 1984 325e did with a bolt on the side of engine, and made the job much easier...

 

Well, i guess i've flushed radiator fluid the wrong way, but it worked. I emptied the radiator and the tank with the little petcock(not sure if that is what it is called) on the bottom. Then I filled it up with water and ran the car with the petcock open with the water continously filling the radiator. The thermostat will open and the clean water will fluch out the block. Then I would just drain the water from the radiator again (with engine off as to not suck up air) and refill with a 50:50 mix. Nice clean fluid after that!

 

Thanks for the info,

 

I thought about doing something like that but if you continuously fill up with water, you will end up having only water in the block. The the 50/50 mix you put in will be diluted by this water stuck in the block. Also, what type of water are you filling with? If your flushing with non-pure water, it's going to cause corrosion as you won't be able to get all of it out.

My plan is to flush it every 2 years and try get enough of the old stuff out that by the time the current fill goes bad, it would have been flushed several times and nearly all of it would be out. I'm using the Prestone (all makes all models) which should last a long time and doesn't contain any silicates to harm the seals.

 

I should probably just wait... but I agree, one really needs to change the coolant fluid a few times, with the proper mix of bmw coolant and distilled water each time, until the fluid appears clean... which could take a few times... I paid about $24 for a gallon of bmw coolant, but I think it makes sense to flush it right or leave it as is... Just hate to think my new car is running with dirty fluids, whether it is power steering, coolant, oil, brake, etc..........

 

True, I used water from the tap, but personally, I am really not too concerned about it. Considering the car I did it on drove for another 100K before I sold it without a single coolant problem. If you refill with a 50:50 mix and the water in the block dilutes it to a 47:53 mix, it isn't going to cause any harm unless you are in canada somewhere!!! You could always use one of those coolant measuring tools (I think they measure specific gravity) to find out exactly what your mix is.

I always thought it was actually best to run pure water in places like Arizona and the like??