E46 318i · LATER 2.0L TANK IDENTIFICATION
“E46 318i” is not a complete coolant-tank specification. The later 2.0L N42/N46 application needs to be distinguished from the earlier 1.9L M43, especially when a car’s registration year is close to the 2001 changeover. Start with its engine and build records, then compare the original tank.
Why the build month matters more than the registration year
A car registered in a particular year may have been built earlier. Near a specification change, that distinction is enough to make a year-only search unreliable. Record the actual build month, VIN and confirmed engine information rather than choosing whichever E46 tank appears first.
The later 2.0L tank selection deliberately starts in October 2001. A September build should remain a fitment enquiry, rather than being rounded into the later range. Nor does a later registration make an earlier M43 car an N42/N46 application.
Use a separate path for the earlier M43
| Vehicle record | Selection path |
|---|---|
| 318i sedan, 2.0L N42/N46, 10/2001–02/2005 | Check reference 17117573781 and the later tank shown here. |
| Earlier 318i, 1.9L M43 | Use the M43 tank identification guide and its own application boundaries. |
| September 2001 or an uncertain engine/build record | Request VIN-based confirmation before ordering. |
This is a selection boundary, not a claim that all tanks bearing an E46 description interchange. Retain the complete original reference. If a different number is proposed, ask for the confirmed replacement relationship for the actual vehicle instead of treating a similar shape as proof.
Photograph the base, not just the filler cap
The top of a tank is often easiest to see, but the lower connections and mounting arrangement are important comparison points. For the linked tank, compare the body shape, two lower hose connections, side connection and mounting features with corresponding views of the original.
Take comparison photographs with both tanks oriented alike. Do not infer a connection diameter, tank capacity or pressure rating from the picture. If the installed base is obscured, supply the accessible markings and vehicle records first, then have the workshop document the concealed features during its assessment.
Confirm the level-sensor socket and package contents
The listed assembly includes the cap and a level sensor with a blue two-pin socket. Compare the original plug, visible contact count and locating shape with the actual gallery close-up. Colour is a supporting visual feature, not a substitute for reference and application confirmation.
Vehicle hoses, coolant and the surrounding mounting bracket are excluded. A tank supplied with a cap and sensor therefore still needs a vehicle-specific repair plan. Ask the installer which surrounding items are suitable to retain and which additional parts are required; do not assume the photographed package is a complete cooling-system service kit.
Questions to settle before ordering
Does a coolant-level warning prove the tank needs replacement?
No. This guide identifies the listed assembly; it does not establish the cause of a warning, leak or temperature concern. Have the fault and repair scope assessed before choosing a part.
Can I choose by a matching cap alone?
A cap-side resemblance does not confirm the tank’s base, mounting or sensor connections. Compare the original reference and all accessible connection views as well as the engine and build information.
What should I send for a fitment check?
Supply the VIN, build month, sedan body designation, confirmed N42/N46 engine details, original reference and clear photographs of the tank, lower connections and sensor plug. Mention any previous engine or cooling-system changes.
Reference basis and current listing
The manufacturer’s application record identifies 17117573781 and N42/N46 318i use. The independent Australian tank catalogue provides the 318i build-change warning supporting the narrower range used here.
Review the current later-tank page for its full scope and actual photographs. Installation, coolant specification and bleeding should follow the vehicle-specific workshop procedure; no universal procedure or setting is established by this guide.
Application details reviewed on 4 November 2026. The featured image is an original AI-generated generic workshop-record scene, not a photograph of a BMW or a particular coolant tank. The in-article image shows the actual listed product.