Heater core cooling line O-ring part number?

WheelNut2 · 03-01-2026, 11:36 PM

I've looked all over Realoem and I can't find the part number for the Oring inside of the heater core coolant hose that attaches the upper radiator hose coupling. Does anyone know if this Oring is available on it's own?

kkasson · 03-02-2026, 04:43 PM

You won't find an official part number, only the full hose. There are some full sets of cooling system o-rings available on eBay/Aliexpress/etc...can't comment on quality but they're out there. You could also try one of the big sets from a parts store...one of them might fit.

cbrider73 · 03-09-2026, 09:40 AM

There is a guy on eBay that sells full kits that are good quality.

koerake1 · 03-09-2026, 05:07 PM

If you decide to just replace the o-ring, then make sure its made of EPDM, as it withstands higher temperature than NBR in the long run.

Suvorovo · 03-23-2026, 12:12 PM

https://www.ebay.com/itm/221686602394?var=520536259377

I used this kit and replaced that exact o-ring. No leaks after ~1-month. Some o-rings in this kit are EPDM while others are NBR.

fastboatster · 04-08-2026, 06:46 PM

I wonder if this VW connector fits. I.e., can be put in place of the stock quick connect:
https://www.fcpeuro.com/products/aud...ebi-3b0122291b
when I had that hose disconnected from the upper radiator hose, it looked very similar in size.

03-01-2026, 11:36 PM	#1
WheelNut2 Private 36 Rep 69 Posts Drives: 2006 330i Join Date: Dec 2022 Location: Vancouver, BC iTrader: (0)	Heater core cooling line O-ring part number? I've looked all over Realoem and I can't find the part number for the Oring inside of the heater core coolant hose that attaches the upper radiator hose coupling. Does anyone know if this Oring is available on it's own? Attached Images
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03-02-2026, 04:43 PM	#2
kkasson Captain 756 Rep 994 Posts Drives: 07 328i, 08 528i, 08 X5 3.0si Join Date: Jun 2015 Location: CA iTrader: (0) Garage List 2008 BMW X5 3.0si [0.00] 2008 BMW 528i [0.00] 2007 BMW 328i [0.00]	You won't find an official part number, only the full hose. There are some full sets of cooling system o-rings available on eBay/Aliexpress/etc...can't comment on quality but they're out there. You could also try one of the big sets from a parts store...one of them might fit.
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03-09-2026, 09:40 AM	#3
cbrider73 New Member 18 Rep 23 Posts Drives: 2017 M240i 6MT Join Date: Sep 2024 Location: Knoxville, TN iTrader: (0)	There is a guy on eBay that sells full kits that are good quality. __________________ Current - 2009 328i Coupe 6MT 2017 M240i 6MT
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03-09-2026, 05:07 PM	#4
koerake1 New Member 12 Rep 7 Posts Drives: e30 e90 f31 Join Date: Mar 2026 Location: est iTrader: (0)	If you decide to just replace the o-ring, then make sure its made of EPDM, as it withstands higher temperature than NBR in the long run.
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03-23-2026, 12:12 PM	#5
Suvorovo Lieutenant 309 Rep 536 Posts Drives: Creaky e90 330xi 6MT Join Date: Feb 2022 Location: New Jersey iTrader: (0)	https://www.ebay.com/itm/221686602394?var=520536259377 I used this kit and replaced that exact o-ring. No leaks after ~1-month. Some o-rings in this kit are EPDM while others are NBR.
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04-08-2026, 06:46 PM	#6
fastboatster Major 580 Rep 1,068 Posts Drives: 2009 bmw 328i; 2011 335i Join Date: May 2019 Location: Thrown under the CBus iTrader: (0)	I wonder if this VW connector fits. I.e., can be put in place of the stock quick connect: https://www.fcpeuro.com/products/aud...ebi-3b0122291b when I had that hose disconnected from the upper radiator hose, it looked very similar in size. __________________ 09 328i TiAg 6MT barebones with sport package
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