Aluminum Coolant Expansion Tanks

HondaRC51 · 11-10-2022, 07:03 PM

I have searched all over the forums and can not find the information I am looking for. I recently purchased a stock 2009 335xi 6mt with 39k miles. I noticed a coolant smell after I park it only after spirited driving. I have not been able to find a leak but I purchased all new hoses, mickey mouse fitting and coolant due to the age of the car. I have not purchased a water pump or thermostat as they seam to be working but will price them out if need be. I want to replace my coolant expansion tank with an aluminum one to prevent a factory plastic one failing at any moment but I can only find the relocated tanks. Does anyone know of a company that makes and aluminum tank for the stock location? Could someone relocate the expansion tank to the driver side of the engine bay if they are not running relocated intakes? What would be the benefits of doing so? Thanks in advance for the help!

Brian86 · 11-11-2022, 03:21 PM

I doubt anybody makes an expansion tank that fits in the OE location.

It would be very very expensive to make that irregular shape out of aluminum.

POBEP · 11-12-2022, 01:08 AM

It does not fail that often.

The plastic OE would probably good for another 10Y+ at ~$60
FCP would give it lifetime warranty.

I own 2009 E91(106K mi), 2011 E90(147K mi) & 2013 E70 (101K mi) - all on factory tanks & water pumps.

My INDY mentioned that current replacement part is an updated version and holds up well.

rbryantaz · 11-14-2022, 02:38 PM

They exist. I have seen a couple of versions including one from turner but it does seem to move the tank to the left side: https://www.turnermotorsport.com/p-5...tion-kit-335i/

There are also several for the e90 M3 which are basically like the turner kit that move the tank to the left side (which many people have done to run turbo side silicone inlets).

I think I have also seen one that sits on the right at some point.

IMO it isn't worth it. I agree with the previous post, an OEM replacement is under $100 so you could replace it 6-10 times for the cost of the aluminum one. If done every 5 years they should be very reliable... I just did the one on my 2008 335i as preventative maint after the one on my e70 x5 did form a small crack which didn't let it fully pressurize.

-Rich

11-10-2022, 07:03 PM	#1
HondaRC51 Private First Class 251 Rep 122 Posts Drives: 2009 E92 335xi Join Date: Oct 2022 Location: Maryland iTrader: (0) Garage List 2009 335xi E92 [0.00] 2016 BMW S1000RR [10.00]	Aluminum Coolant Expansion Tanks I have searched all over the forums and can not find the information I am looking for. I recently purchased a stock 2009 335xi 6mt with 39k miles. I noticed a coolant smell after I park it only after spirited driving. I have not been able to find a leak but I purchased all new hoses, mickey mouse fitting and coolant due to the age of the car. I have not purchased a water pump or thermostat as they seam to be working but will price them out if need be. I want to replace my coolant expansion tank with an aluminum one to prevent a factory plastic one failing at any moment but I can only find the relocated tanks. Does anyone know of a company that makes and aluminum tank for the stock location? Could someone relocate the expansion tank to the driver side of the engine bay if they are not running relocated intakes? What would be the benefits of doing so? Thanks in advance for the help!
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11-11-2022, 03:21 PM	#2
Brian86 Captain 638 Rep 766 Posts Drives: e36 M3, e91 325xi, N50 Xterra Join Date: Dec 2020 Location: Pittsburgh iTrader: (0)	I doubt anybody makes an expansion tank that fits in the OE location. It would be very very expensive to make that irregular shape out of aluminum. __________________ Sometimes a bolt is just a bolt.
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11-12-2022, 01:08 AM	#3
POBEP Lieutenant 366 Rep 553 Posts Drives: E70 E90 E91 Join Date: Mar 2016 Location: Christmas Valley, CA iTrader: (0) Garage List 2011 E90 335d [9.33] 2013 E70 xDrive35d [5.00] 2009 E91 328i [10.00] 2016 F25 xDrive28d [0.00]	It does not fail that often. The plastic OE would probably good for another 10Y+ at ~$60 FCP would give it lifetime warranty. I own 2009 E91(106K mi), 2011 E90(147K mi) & 2013 E70 (101K mi) - all on factory tanks & water pumps. My INDY mentioned that current replacement part is an updated version and holds up well. __________________
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11-14-2022, 02:38 PM	#4
rbryantaz Lieutenant 372 Rep 531 Posts Drives: 2007 E70 4.8i, 2008 E90 335i Join Date: Jul 2015 Location: Phoenix, AZ area iTrader: (4) Garage List 2008 BMW 335i [7.67] 2007 BMW X5 4.8i [10.00]	They exist. I have seen a couple of versions including one from turner but it does seem to move the tank to the left side: https://www.turnermotorsport.com/p-5...tion-kit-335i/ There are also several for the e90 M3 which are basically like the turner kit that move the tank to the left side (which many people have done to run turbo side silicone inlets). I think I have also seen one that sits on the right at some point. IMO it isn't worth it. I agree with the previous post, an OEM replacement is under $100 so you could replace it 6-10 times for the cost of the aluminum one. If done every 5 years they should be very reliable... I just did the one on my 2008 335i as preventative maint after the one on my e70 x5 did form a small crack which didn't let it fully pressurize. -Rich __________________ 2007 E70 X5 4.8i with 10" android screen Running 265/60/18 AT34s All Terrains (Mainly for road trips) 2008 E90 335i with 10" android screen, 7" intercooler, inlets, Dinan intake, JB4 BEF, E85 conversion, Mfactory LSD, M3 suspension, EDC shocks with custom controller. Last edited by rbryantaz; 11-14-2022 at 02:44 PM..
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