The 2018 Audi A3 has 13 ignition parts with verified fitment on this page — 7 part types and 9 brands, covering all 4 engine options (1.4L L4 ELECTRIC/GAS Turbocharged, 1.4L L4 Turbocharged, 1.8L L4 Turbocharged and 2.0L L4 Turbocharged). Each part includes a manufacturer part number and application notes.
The ignition system on the 2018 Audi A3 delivers spark at the right moment — plugs, coils, wires, distributors and ignition modules. The largest groups are Camshaft Position Sensor (3 parts), Crankshaft Position Sensor (3 parts) and Ignition Lock Housing (2 parts). The other 4 part types cover the remaining 5 parts.
The 2018 Audi A3 was sold with 4 engines. Every part on this page is engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2018 Audi A3 ignition parts are MARELLI (3 parts), WALKER PRODUCTS (2 parts) and ELRING (2 parts), plus 6 more brands.
Each part number listed for the 2018 Audi A3 opens a page with every vehicle that part fits.
Camshaft Position Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MARELLI Fits: 1.8L L4 Turbocharged | SAC120 | 🇲🇽 MX | View on Amazon | |
| STANDARD MOTOR PRODUCTS Fits: 1.8L L4 Turbocharged | PC984 | 🇲🇽 MX | Connector Shape: Rectangular | View on Amazon |
| WALKER PRODUCTS Fits: 1.8L L4 Turbocharged | 2352067 | 🇲🇽 MX | Sensor OnlyConnector Shape: Oval | View on Amazon |
This table covers the sensors that report camshaft position to the ECU. Typical signs include a stall, a no-start, or a code for cam or crank correlation. Check the connector and the reluctor gap before replacing the sensor.
3 Camshaft Position Sensor parts are listed for the 2018 Audi A3, from MARELLI, STANDARD MOTOR PRODUCTS and WALKER PRODUCTS.
Listed part numbers: MARELLI SAC120, STANDARD MOTOR PRODUCTS PC984 and WALKER PRODUCTS 2352067.
Crankshaft Position Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MARELLI Fits: 1.8L L4 Turbocharged | SAG243 | 🇲🇽 MX | From 10/2013 | View on Amazon |
| MARELLI Fits: 1.8L L4 Turbocharged | SAG289 | 🇲🇽 MX | View on Amazon | |
| WALKER PRODUCTS Fits: 1.8L L4 Turbocharged | 2351589 | 🇲🇽 MX | Sensor Only | View on Amazon |
This table covers the sensors that report crankshaft position and engine speed. Typical signs include a stall, a no-start, or a code for cam or crank correlation. Check the connector and the reluctor gap before replacing the sensor.
3 Crankshaft Position Sensor parts are listed for the 2018 Audi A3, from MARELLI and WALKER PRODUCTS.
Listed part numbers: MARELLI SAG243, MARELLI SAG289 and WALKER PRODUCTS 2351589.
Ignition Coil
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| KARLYN / BREMI / STI Fits: 1.8L L4 Turbocharged | 20529 | 🇲🇽 MX | Bremi-STI Direct Ignition Coil Unit | View on Amazon |
This table covers the coils that fire each spark plug. Typical signs include a misfire that follows one cylinder, a snap in damp weather, or a coil that is swollen or cracked. Swap a suspect coil with a neighbor to confirm, then replace boots that tore on the way off.
One part is listed for the 2018 Audi A3 — KARLYN / BREMI / STI 20529.
Ignition Lock Cylinder
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Fits: 1.8L L4 Turbocharged | 4H1924 | 🇲🇽 MX | Includes Switch | View on Amazon |
This table covers the lock cylinders in the ignition switch.
One part is listed for the 2018 Audi A3 — WELLS 4H1924.
Ignition Lock Housing
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 1.8L L4 Turbocharged | 926593 | 🇲🇽 MX | View on Amazon | |
| ÜRO PARTS Fits: 1.8L L4 Turbocharged | 1K0905851B | 🇲🇽 MX | Includes Ignition Switch | View on Amazon |
This table covers the Ignition Lock housings.
2 Ignition Lock Housing parts for the 2018 Audi A3 come from 2 brands — DORMAN and ÜRO PARTS.
Part numbers include DORMAN 926593 and ÜRO PARTS 1K0905851B.
Spark Plug
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| NGK Fits: 1.8L L4 Turbocharged | 94833 | 🇲🇽 MX | Laser PlatinumPre-Set Gap: 0.032" | View on Amazon |
This table covers the spark plugs for this engine. Typical signs include misfire under load, rough idle, or a flashing check-engine light. Verify the gap even on pre-gapped plugs, and replace coil boots that come off a high-mileage engine.
This group shows a single part: NGK 94833.
Spark Plug Tube Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ELRING Fits: 1.8L L4 Turbocharged | 380150 | 🇲🇽 MX | Inner Diameter [MM]: 21Material: Ethylene Acrylic Elastomer (AEM) | View on Amazon |
| ELRING Fits: 1.8L L4 Turbocharged | 811540 | 🇲🇽 MX | Inner Diameter [MM]: 19Material: Ethylene Acrylic Elastomer (AEM) | View on Amazon |
This table covers the seals at the Spark Plug Tube. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
ELRING supplies both parts for the 2018 Audi A3.
Part numbers include ELRING 380150 and ELRING 811540.
Buying Ignition Parts for a 2018 Audi A3
On this vehicle, the ignition system delivers spark at the right moment — plugs, coils, wires, distributors and ignition modules.
- Match the engine first. Every ignition part here is engine-specific; each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace plugs and wires (or coil boots) as a set — one weak cylinder makes the whole set feel bad.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Camshaft Position Sensor and Crankshaft Position Sensor .
Frequently Asked Questions
How many ignition parts fit the 2018 Audi A3?
Our catalog currently lists 13 ignition parts for the 2018 Audi A3 across 7 subcategories and 9 brands, covering all 4 engine options (1.4L L4 ELECTRIC/GAS Turbocharged, 1.4L L4 Turbocharged, 1.8L L4 Turbocharged and 2.0L L4 Turbocharged). Each part is matched to the engine(s) it fits.
Do ignition parts differ between 2018 Audi A3 engines?
Yes. Every ignition part on this page is engine-specific. Each row shows which engine(s) it fits — use the filter at the top to hide the rest. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of ignition problems on a 2018 Audi A3?
Common symptoms include misfires under load, rough idle, flashing check-engine light, or poor starting in damp weather. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What spark-plug gap is listed for the 2018 Audi A3?
Notes on this page include a 0.032" pre-set gap. Still verify against spec — even “pre-gapped” plugs should be checked before they go in.
What should I replace at the same time?
Where labor overlaps, replace plugs and wires (or coil boots) as a set — one weak cylinder makes the whole set feel bad.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2018 Audi A3 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2018 Audi A3?
First match the engine — each row shows which engine(s) the part fits. Then gap matters even on “pre-gapped” plugs — verify against spec, and replace coil boots when they come off a high-mileage engine. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2018 Audi A3
Ignition Parts for Other Audi A3 Years
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