We assembled this kit for overhauling cooling systems on the BMW E46 323, 325, 328, & 330i.  We also have kits for Euro spec. 316, 318, & 320. If ordering from outside North America, please include a note with the last 7 digits of your vehicle's VIN or production date, model number, & engine type.   

These o-rings seal the BMW press & clip hose connections.  Our o-rings are made in the USA with unparalleled quality and fit.

We're the 1st in the world to offer these kits for BMW cooling systems and with trial and testing on vehicles we ourselves service, our kits optimize performance, quality, and value through the use of multiple compounds (NBR, HNBR, EPDM).  All the green o-rings in our kits are peroxide cured EPDM, which we use in the most vulnerable locations for its excellent high & low temperature performance (-30C/-22F-150C/300F), resistance to compression set, and chemical resistance to glycol based coolants.  We have transitioned all of our kits to more of these EPDM o-rings for the most vulnerable and highly stressed connections.  Also included is a packet of water based lube, which can be used on all coolant connections. Many copycats out there now, but go with the original.   


When encountering o-rings of identical size, green ones may be used only for coolant connections.

Do not use petroleum based lubricants on any coolant connections!

***Due to feedback from customers, kits for the M52 and M54 engines no longer contain the rarely needed 4 x BMW Part # 11531435808.  Instead, we have replaced them a few extras of other commonly needed ones because in the rare instance that you're removing the coolant pipes, you'll more than likely need to replace them with new ones that come with new o-rings already installed on their ends.  If, however, you need these o-rings, please send us a note with your order or message us, and we'll send you one of the original kits, which includes them.  As always, we use the optimal compound for this application.  

The M3 kit for the S54 engine also includes the thermostat o-ring (BMW Part # 11531318402) as well as 2 of each of the following o-rings: BMW Part # 11537830709 & 11537830712.
Euro spec. cars with the N42 and N46 engines will also include 2 x BMW Part# 11517514942 for the water pump to cylinder head connector pipe.   

*Standard shipping is USPS 1st Class Package, 2-5 days in most cases.  If you need your item sooner choose expedited shipping, USPS Priority Mail 2-3 days or USPS Priority Express 1-2 days guaranteed (with exceptions).

Attention UK buyers, due to Brexit policies, Ebay will now collect VAT on all sales beginning 1 January 2021.  There will no longer be a VAT exemption for small consignments up to £15.

We carry a large inventory.  For orders of more than 10 kits, please contact us!

For other complete vehicle kits, please click the proceeding links:


These are metric o-rings and are of the same dimensions as the ones that came on your car.  The cooling system on the e46 (and many other BMWs) requires a good deal of maintenance, especially the expansion tank (ET) and thermostat.  In most cases, the o-rings at the connection points will leak after they've been disconnected due to compression set.  During winter, leaks tend to develop as the already compressed rubber o-rings contract with lower ambient temperatures.

BMW does not offer o-rings for their press & clip hose connections and most dealerships do not stock the o-ring for the coolant temperature sensor in the lower radiator hose separately.   But don't waste money buying a new sensor or unnecessarily replacing hose assemblies, all of which can last well beyond 150,000 miles.  We've assembled this kit for working on customers' vehicles because We grew tired of throwing away countless serviceable parts when all that was needed were some fresh o-rings.   

The complete kit contains 19 to 27 o-rings depending on whether the car is equipped with a manual or an automatic transmission, respectively:

For example, cars equipped with the M52 or M54 engine contain the following o-rings.  
  1. 5 x o-rings for upper and lower radiator hoses and larger of the 2 o-rings at the bottom of the expansion tank
  2. 6 x o-rings for heater & return hose connections and smaller of the 2 o-rings at the bottom of the expansion tank* (1 spare)
  3. 2 x o-ring for smaller hose at the top of the expansion tank (1 spare)
  4. 1 x o-ring for coolant temperature sensor in the lower radiator hose (13621743299)
  5. 1 x o-ring for coolant bleeder screw****
  6. 3 x o-rings for automatic transmission heat exchanger circuit, (17111711987)***
  7. All diesel powered vehicles will included BMW part # 11532248435.  Those with the M47 engine will also include BMW part # 11537786258

* If you're replacing the ET, new o-rings are already installed for the bottom connections.  You'll likely only need 2 or 3 of these o-rings for the heater & return hose connections to the ET and ET mounting plate.  Spares can be used to replace the o-rings on the ET cap.  However, if you're also replacing the cap, I recommend going with a 1.4 Bar cap (BMW Part # 17111742232) used in almost all newer (and older) BMWs in lieu of the 2.0 Bar cap.

Use silicone grease, available at any hardware or plumbing supply store, to install your o-rings, particularly the temperature sensor o-ring.  This will prevent kinking or damaging the o-rings during installation and ease future removal.  Do not use petroleum based lubricants as they will degrade the coolant hoses and plastics in the cooling system. 

On cars with automatic transmissions, the heat exchanger adds weight and stress to the mounting plate, where all the connections around the bottom of the expansion tank have more of a tendency to leak .  There are 2 o-rings for the heat exchanger to coolant distribution pipe & ET mounting plate and 1 o-ring for the mounting plate to radiator connection.

****We would also suggest you order a new coolant bleeder screw (BMW Part #17111712788). Over time, the heads have a tendency to shear off due to heat fatigue.  I've seen this happen on quite a few vehicles, and this precaution can save you a good deal of time and aggravation, not to mention money.  Keep the old one in your glove compartment as a spare.  Though less common, We've also seen the heads of the coolant drain plugs shear off, which would not cause an immediate leak but would, nonetheless,  require replacement.  There are 2 drain screws for cars with manual transmission:  one for the radiator (BMW Part #17111437361) and one for the expansion tank mounting plate (BMW Part #17111707818) .  Cars with automatic transmissions have only the radiator drain screw. 

Use a large phillips screwdriver for these plastic screws, and do not over tighten.  Finally, do not overfill your cooling system as this will prevent the cap from venting excess pressure.  After bleeding the system, siphon out excess coolant until the level is at the upper mark.  Top up as needed after each of the first couple heating and cooling cycles.   

The photo in this listing is generic.  Our complete vehicle kits contain 19-34 o-rings.