Coolant Leak unknown source

QKRTHNU · 01-20-2015, 02:25 PM

My 2009 135i w/ 65k miles just developed a coolant leak. Based on all the posts I was assuming it would be a pump/thermostat issue, but it looks like it may be in a different area.

The coolant is ending up in a small pool on the drivers side. I don't see traces of it running down from anywhere, just this small pool that drains out the nearby opening in the plastic tray and ends up inside and just in front of the drivers side front wheel.

Has anyone here seen this before?

koluka · 01-20-2015, 02:38 PM

I am pretty sure your coolant expansion tank is cracked. I noticed mine cracked when I saw coolant gas escaping from the tank on the cracked side. Hard to notice unless the coolant is hot. Replacement tanks run around $90

MightyMouseTech · 01-20-2015, 02:42 PM

Quote:

Originally Posted by koluka

I am pretty sure your coolant expansion tank is cracked. I noticed mine cracked when I saw coolant gas escaping from the tank on the cracked side. Hard to notice unless the coolant is hot. Replacement tanks run around $90

The expansion tank is on the other side of the car.

Not much around there other than being directly behind the rad, and the upper rad hose is in the top of the pic.

May have a pinhole leak in the rad. Will have to get the system pressurized and start looking.

QKRTHNU · 02-05-2015, 01:21 PM

So, this doesn't make any sense but since I topped off the coolant I haven't had any more leaking.

QKRTHNU · 02-09-2015, 02:36 PM

Apparently even though my coolant was ~1 liter low, it wasn't leaking.
It's my washer fluid that is leaking. Thanks BMW for making those the same color.

MightyMouseTech · 02-09-2015, 04:41 PM

Guess this is why they recommend OEM washer fluid only, which is purple here in NA.

mackeroni · 02-15-2015, 06:03 PM

Happened on my 2011 135i too. Washer fluid leak from cracked nozzle way back at 15,357 miles. Fairly extensive warranty repair. (Thank God.)

01-20-2015, 02:25 PM	#1
QKRTHNU New Member 2 Rep 12 Posts Drives: 2009 135i Join Date: Jul 2013 Location: OH iTrader: (0)	Coolant Leak unknown source My 2009 135i w/ 65k miles just developed a coolant leak. Based on all the posts I was assuming it would be a pump/thermostat issue, but it looks like it may be in a different area. The coolant is ending up in a small pool on the drivers side. I don't see traces of it running down from anywhere, just this small pool that drains out the nearby opening in the plastic tray and ends up inside and just in front of the drivers side front wheel. Has anyone here seen this before?
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01-20-2015, 02:38 PM	#2
koluka Enlisted Member 8 Rep 49 Posts Drives: BMW 135i LMB MSPORT Join Date: Oct 2012 Location: UNIVERSITY PLACE, WASHINGTON iTrader: (0)	I am pretty sure your coolant expansion tank is cracked. I noticed mine cracked when I saw coolant gas escaping from the tank on the cracked side. Hard to notice unless the coolant is hot. Replacement tanks run around $90
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02-05-2015, 01:21 PM	#4
QKRTHNU New Member 2 Rep 12 Posts Drives: 2009 135i Join Date: Jul 2013 Location: OH iTrader: (0)	So, this doesn't make any sense but since I topped off the coolant I haven't had any more leaking.
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02-09-2015, 02:36 PM	#5
QKRTHNU New Member 2 Rep 12 Posts Drives: 2009 135i Join Date: Jul 2013 Location: OH iTrader: (0)	Apparently even though my coolant was ~1 liter low, it wasn't leaking. It's my washer fluid that is leaking. Thanks BMW for making those the same color.
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02-09-2015, 04:41 PM	#6
MightyMouseTech Major General 4338 Rep 6,196 Posts Drives: 13 135i 6MT LeMans Blue MSport Join Date: Feb 2013 Location: Ottawa, Canada iTrader: (0)	Guess this is why they recommend OEM washer fluid only, which is purple here in NA.
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02-15-2015, 06:03 PM	#7
mackeroni Former Opel GT Pilot 327 Rep 771 Posts Drives: 2011 135i, AW, CR, 6MT Join Date: Dec 2010 Location: Canton, OH USA iTrader: (0)	Happened on my 2011 135i too. Washer fluid leak from cracked nozzle way back at 15,357 miles. Fairly extensive warranty repair. (Thank God.) __________________ So, that's it. I am doomed. There is no patch, no methadone, no substitute. Curse you BMW. Curse you and your seamless power delivery. Curse the incredible sense of road feel. Curse the comfort, the luxury, the envious looks from the masses. I am... hopelessly addicted.
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