Common Expansion Tanks Leak Points?

cjdzombie · 06-05-2018, 10:12 AM

I noticed a bit of coolant on my garage floor yesterday. When I popped the hood I found that there was dried coolant spatter around the engine side of the expansion tank. I couldn't really tell at that point where the source was. I plan on getting a good look this evening after my drive home from work. Are there any common leak areas that I should focus on? Do I have a cracked tank?

Here are a couple pictures:

NRigs · 06-05-2018, 10:37 AM

Best bet is to add some dye to it and trace the leak with a UV light. I am going to be doing the same soon. I have a leak on my driver's side.

weehe126 · 06-05-2018, 11:47 AM

The cap can leak if pressure gets too high and any of the plastic seams can crack/leak. If it is leaking enough that you need to regularly top it up, Id just get a new tank.

NRigs · 06-05-2018, 12:15 PM

Quote:

Originally Posted by cjdzombie

Here are a couple pictures:

Pictures aren't working

cjdzombie · 06-05-2018, 02:00 PM

Quote:

Originally Posted by NRigs

Pictures aren't working

Here are some links to the images:

https://photos.app.goo.gl/NVFvCppkAbGHHizz7
https://photos.app.goo.gl/nH0jeEyxvEC0cHIj2

Kage893 · 06-05-2018, 07:43 PM

Looks similar to when my tank started to leak at 60k miles.

cahme · 06-05-2018, 09:40 PM

Mine leaked at the seam where the two tank halves were glued. I couldn't see it,but could hear it just after shutdown at full operating temp.

cjdzombie · 06-06-2018, 07:45 AM

I purchased a new tank and some BMW coolant this morning. Should be here by Saturday for the swap.

06-05-2018, 10:12 AM	#1
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	Common Expansion Tanks Leak Points? I noticed a bit of coolant on my garage floor yesterday. When I popped the hood I found that there was dried coolant spatter around the engine side of the expansion tank. I couldn't really tell at that point where the source was. I plan on getting a good look this evening after my drive home from work. Are there any common leak areas that I should focus on? Do I have a cracked tank? Here are a couple pictures: __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter Last edited by cjdzombie; 06-05-2018 at 11:10 AM..
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06-05-2018, 10:37 AM	#2
NRigs Lieutenant 94 Rep 321 Posts Drives: 2011 BMW 335xi Join Date: Feb 2017 Location: Ma iTrader: (0)	Best bet is to add some dye to it and trace the leak with a UV light. I am going to be doing the same soon. I have a leak on my driver's side. __________________ Current: 2011 BMW 335xi \| Wedge Tuned \| Meth \| VRSF DP \| VRSF 5" Intercooler \| VRSF Chargepipe \| BMS Intake \| xHP Stg 3 Totaled:2014 Audi A4 CTS K04 APR Tuned
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06-05-2018, 11:47 AM	#3
weehe126 Brigadier General 1161 Rep 3,189 Posts Drives: 2017 340i Join Date: Apr 2014 Location: San Antonio iTrader: (2)	The cap can leak if pressure gets too high and any of the plastic seams can crack/leak. If it is leaking enough that you need to regularly top it up, Id just get a new tank.
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06-05-2018, 07:43 PM	#6
Kage893 New Member 4 Rep 15 Posts Drives: 2011 E90 335i M-Sport Join Date: Feb 2014 Location: Irvine, CA iTrader: (1)	Looks similar to when my tank started to leak at 60k miles.
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06-05-2018, 09:40 PM	#7
cahme Second Lieutenant 116 Rep 226 Posts Drives: '11 E90 335i Sport MT Join Date: Jul 2015 Location: Texas iTrader: (0)	Mine leaked at the seam where the two tank halves were glued. I couldn't see it,but could hear it just after shutdown at full operating temp.
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06-06-2018, 07:45 AM	#8
cjdzombie First Lieutenant 76 Rep 290 Posts Drives: 2011 E92 335i xDrive, M Sport Join Date: Dec 2015 Location: Cincinnati iTrader: (0)	I purchased a new tank and some BMW coolant this morning. Should be here by Saturday for the swap. __________________ 2011 E92 335i xDrive M-Sport MHD 93 Stage 2+ \| xHP Stage 3 \| xDelete \| Catless Downpipe \| Phoenix Racing Intercooler \| ARM CP \| AFE Drop In Filter
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