2016 528 leaking coolant from lower pass side wheel well

jmmdm2 · 08-10-2023, 06:27 PM

Checked the typical issue with the expansion tank, it’s dry all around. Performed bleed procedure, noticed a decent leak from the lower passenger side wheel well around vents toward front.

Is there an auxiliary radiator in there? I see the fins but assumed it was for motor oil or trans fluid. Is the coolant overflow routed to that location? Friggin raining so can’t tear into it tonight and all searches come up empty. I’m obviously not using the correct criteria.

Johnkwick · 08-11-2023, 07:05 AM

yes, there's an aux radiator on lower right side of the car. Could be either a hose that goes into the aux, or the aux rad that's leaking

I also have leaking coolant coming from hose that goes into aux rad, but it will leak when pressure in the cooling system starts to decline. I haven't replaced it yet since the rate of coolant loss is low (1x 500ml top up per 3-4 weeks)

View post on imgur.com

This should be the p/n for the hose: 17127619693
aux rad: 17117802662

jmmdm2 · 08-11-2023, 07:14 AM

Much appreciated! I’ll tear into it tonight.

08-10-2023, 06:27 PM	#1
jmmdm2 Private 45 Rep 81 Posts Drives: 2015 528i xdrive M-Sport Join Date: Jul 2018 Location: CT iTrader: (0) Garage List 2019 BMW M550i [0.00]	2016 528 leaking coolant from lower pass side wheel well Checked the typical issue with the expansion tank, it’s dry all around. Performed bleed procedure, noticed a decent leak from the lower passenger side wheel well around vents toward front. Is there an auxiliary radiator in there? I see the fins but assumed it was for motor oil or trans fluid. Is the coolant overflow routed to that location? Friggin raining so can’t tear into it tonight and all searches come up empty. I’m obviously not using the correct criteria.
	Appreciate 0 Tweet Quote

08-11-2023, 07:05 AM	#2
Johnkwick Private 24 Rep 94 Posts Drives: F10 LCI Join Date: Mar 2020 Location: Southern Nusa Dua, Bali iTrader: (0)	yes, there's an aux radiator on lower right side of the car. Could be either a hose that goes into the aux, or the aux rad that's leaking I also have leaking coolant coming from hose that goes into aux rad, but it will leak when pressure in the cooling system starts to decline. I haven't replaced it yet since the rate of coolant loss is low (1x 500ml top up per 3-4 weeks) View post on imgur.com This should be the p/n for the hose: 17127619693 aux rad: 17117802662
	Appreciate 0 Quote

08-11-2023, 07:14 AM	#3
jmmdm2 Private 45 Rep 81 Posts Drives: 2015 528i xdrive M-Sport Join Date: Jul 2018 Location: CT iTrader: (0) Garage List 2019 BMW M550i [0.00]	Much appreciated! I’ll tear into it tonight.
	Appreciate 0 Quote