contaminated coolant ?

[Mops]

Hello guys and gals.
I just replaced cambelt and waterpump like a month ago, durnign which I flushed the coolant in radiator and engine block. Aswell I changed the thermostat. Filled up with new cooland (I think 5L of green, glykol based coolant and rest of water). Looked good for first week.

Yesterday I drained some coolant as a part of another job I was doing, and I noticed that it isn't clear, looks like has some small particles hanging in there... kinf of like somebody thres and handfull of fine beach sand into it. Looks maby like rust, but I have no clue how would that be possible, since I just flushed the coolant month prior. Previous coolant was somewhat dirty, but by no means very bad. From now on I see two options:

1. Leave as it is, and check the level of contamination. At this stage is't not terrible, but it's not clean and I'm concerned. 2
2. Flush again... maby will fix the problem, but what if the problem comes back ?

I know that glycol goes a good job as a thinner (like paint thinner), and maby fresh coolant is loosening out the s**t from inside ?

[smithy318i]

I know that glycol goes a good job as a thinner (like paint thinner), and maby fresh coolant is loosening out the shit from inside ?

you just answered your own question.

[Mops]

hehe.
but should i replace coolant now, or maby wait until it loosens up some more ? should i be concerned at all ? All my previous cars had nice clear coolant, just my BMW has "muddy" additive

[smithy318i]

I wouldnt be concerned at all with it. However if you feel you need coolant without 'bits' replace it if you want.

then again what's to say you wont get more 'bits' later after you put even more fresh coolant in?

With mine i dont care if it has bits. as long as it stays within the MIN and MAX markers and is a darkish blue colour.

[tourer-dan]

I think the sand is 'normal'. Or at least acceptable. I had loads of this when I did mine. I wondered if it might have been sand left behind during casting, but seeing as it was dyed I would doubt it!!

I noticed today when checking mine that it's turning a blackish colour

[Steviec]

I noticed today when checking mine that it's turning a blackish colour

Mines the same, im giving it a good flush through over the weekend.