HELP! White Gunk in Coolant tank.
 

Recently had spent ton of money fixing my 2011 x5 (35i) had a bad ofhg leak which was causing the coolant reservoir tank to have a muddy mixture. Coolant sensor was bad in that tank supposedly and replaced that tank. 5 coolant flushes a new water pump, thermostat and gaskets, I’m good to go.

Fast forward present say my coolant light is on.. wait for the car to cool down and the coolant is way below the “min” sign inside. Coolant itself is a blue/green color but there this white residue which looks like frost but it’s clearly not since obviously the coolant heats up. What could this be?

Was mix water distilled?

I could not tell you off hand. I had an Indy do all the work. They stressed how many time’s they had to flush lines because of the initial oil contamination from the bad oil filter house gasket leak.. to put it into perspective my belt was soaked in oil too.. was a long time coming from previous owner I jus trust have missed it. Frankly I can’t imagine anyone using numerous gallons of distilled water by hand to flush.. wouldn’t be shocked if at first it was regular water..

Any suggestions? Car runs decent. No change in behavior

Regular water was certainly used for wash/flush. Are you saying there is something like foam on the top or film on the sides?

Either way I suspect some minor residual from the cleaning agent

The best description is candle wax stuck to the side walls of this tank.. I’m tempted to go out and take a picture.

The mix and max symbol are both visible and the bottom portion of the coolant looks normal a blue-ish color. No residue of any down in that direction.

Best picture I could get https://ibb.co/pwhzj6M

It reminds me of what happens if you spill DEF. I would just wipe it out and see if it returns. It looks like leftover from the cleaning agent to me and amounts to 0.002% of the volume off the coolant. Report back if it comes back

Thanks. Will clean tomorrow. I have some bmw coolant in my garage oddly. Since it’s cold is it okay to not add distilled water? I notice this stuff is blue and pretty thick.

Update: coolant clearly leaking from driver side tire area. More so leaking directly under car close to the oil drain plug area...