OVERVIEW
Genuine VW/Audi Coolant Temperature Sensor O-Ring
N-903-168-01 is an original round sealing ring for specified coolant temperature sensor and coolant pipe connections. Its nominal 19.6 x 3.65 mm size identifies the seal required at those assigned joints. The ring seals between the installed component and its receiving bore or housing; correct seal size, groove condition and component seating are essential to retaining coolant. This is one individual O-ring, supplied without a sensor, retaining clip, pipe or coolant.
Technical details
- OEM number: N-903-168-01 / N90316801.
- Nominal O-ring size: 19.6 x 3.65 mm.
- Form: Round-section sealing ring for designated coolant-system connections.
- Application: Coolant sensor and pipe sealing positions that explicitly specify this OEM number.
- Supply: One individual seal. Additional retaining hardware and related components are separate.
Common reasons to replace
A worn seal can leave coolant moisture or dried residue around the sensor or pipe joint. Heat cycling and age can leave a seal hardened, flattened or unable to recover its original shape. A ring can also be cut, rolled or pinched during removal and refitting. Replace a damaged or missing seal when servicing its assigned connection, and follow the repair procedure's seal-renewal instructions when the sensor or pipe is removed. A new O-ring will not repair a cracked housing, a damaged sealing bore, a broken retaining clip or a defective temperature sensor; inspect those components when diagnosing leakage or an electrical sensor fault.
Installation and service notes
Allow the engine to cool fully and follow the prescribed cooling-system depressurization and coolant-draining procedure before opening the connection. Remove the old ring completely, clean the groove and inspect the bore and component sealing surfaces without scratching them. Fit the new ring in its assigned groove and use only the assembly lubrication specified by the vehicle's repair instructions. Seat the component evenly and secure the appropriate retaining hardware. Refill and bleed the cooling system with the specified coolant and procedure, then check the serviced joint for leakage. Match the original part number and sealing position; a similar-looking O-ring or a flat gasket is not a substitute.
Vehicle fitment
The following confirmed applications require the coolant connection assigned to N90316801. Engine, body style and original component configuration must match the row; this seal is not assigned to every coolant joint on a listed vehicle.
| Vehicle | Model years | Engine | Configuration | Application restrictions |
|---|---|---|---|---|
| Audi A3 | 2015–2020 | 2.0L turbo gasoline | quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A3 Sportback e-tron | 2016–2018 | 1.4L turbo plug-in hybrid | Sportback; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A4 | 2009–2016 | 2.0L turbo gasoline | Front-wheel drive; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A4 | 2009–2016 | 2.0L turbo gasoline / flex-fuel, as equipped | quattro; sedan / Avant where specified; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A5 | 2010–2014 | 2.0L turbo gasoline | Front-wheel drive; Cabriolet; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A5 | 2010–2017 | 2.0L turbo gasoline / flex-fuel, as equipped | quattro; body style matched by VIN; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A5 Sportback | 2018–2019 | 2.0L turbo gasoline | Sportback; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi A6 | 2012–2015 | 2.0L turbo gasoline | Front-wheel drive; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen Golf Alltrack | 2017–2019 | 1.8L turbo gasoline | Mk7; wagon; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen Arteon | 2019–2023 | 2.0L turbo gasoline | Front-wheel drive / 4Motion, as equipped; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen CC | 2009–2017 | 2.0L turbo gasoline | Match original coolant connection; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen Eos | 2007–2015 | 2.0L turbo gasoline | Convertible; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen Golf SportWagen | 2015–2017 | 1.8L turbo gasoline | Mk7; wagon; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen GTI | 2015–2017 | 2.0L turbo gasoline | Mk7; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Volkswagen Golf R | 2015–2017 | 2.0L turbo gasoline | Mk7; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi S4 | 2011–2012 | 3.0L supercharged gasoline V6; CCBA | Base; quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi S4 | 2013 | 3.0L supercharged gasoline V6; CGXC | Base; quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi S4 | 2014–2016 | 3.0L supercharged gasoline V6; CTUB | Premium Plus / Prestige; quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi S5 | 2010–2012 | 3.0L supercharged gasoline V6; CAKA / CCBA | Cabriolet; quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi S5 | 2013 | 3.0L supercharged gasoline V6; CGXC | Base / Cabriolet; quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
| Audi S5 | 2015–2016 | 3.0L supercharged gasoline V6; CTUB | Premium Plus / Prestige; coupe / Cabriolet; quattro; Match original coolant sensor or pipe connection | Only coolant connections specifying N90316801; confirm the original seal location and VIN. |
Confirm N90316801, original coolant connection and vehicle configuration by VIN before ordering.