N90316802 WHT001709 Coolant Temperature Sensor O-Ring Seal for VW Beetle and Jetta: Diagnosis and OE Fitment Guide

QUICK ANSWER

A confirmed flattened, damaged or leaking coolant-temperature-sensor sealing ring should be confirmed through physical inspection and the workshop checks appropriate to this component before a replacement part is ordered. The same symptom can have more than one cause, so compare the installed component, all OE references, connections and vehicle information.

WHAT THIS PART DOES

The Coolant Temperature Sensor O-Ring Seal seals the interface between the coolant temperature sensor and the coolant flange or hose to prevent coolant loss at the sensor seat. Its role does not prove that it is the cause of a customer complaint; diagnosis must connect the observed fault to this component.

SYMPTOM SNAPSHOT

• Coolant loss or wetness is traced to the temperature-sensor sealing interface
• The O-ring is flattened, brittle, cut or missing during sensor service
• A sensor replacement still leaks because the old seal is damaged
• The sensor does not seat securely after the flange and sensor are inspected

These symptoms are diagnostic clues, not a guarantee that this part has failed.

DIAGNOSIS BEFORE ORDERING

1. Allow the cooling system to cool and relieve pressure before inspection
2. Confirm the leak is at the sensor seal rather than the flange, hose, sensor body or nearby joint
3. Compare O-ring diameter, cross-section, material, sensor groove and every OE reference
4. Inspect the sensor seat and flange for cracks, corrosion, dirt or distortion
5. Confirm vehicle, engine, cooling-flange configuration and VIN before ordering
6. After installation, refill and bleed the cooling system as specified and recheck for leaks

OEM REFERENCE

• N90316802
• WHT001709

Every verified OE reference from the product record is retained. Revision letters and alternate numbers must not be discarded during comparison.

OE-SPECIFIC BUYING CHECK

• Volkswagen Group parts references identify N90316802 as a 19.6 x 3.65 mm O-ring used to seal the coolant-temperature-sensor connection to the coolant flange or hose.
• N90316802 was superseded by WHT001709 for Volkswagen and Škoda on the Shanghai market; retain both references and verify the installed application.
• Confirm the sensor groove, flange condition, seal dimensions, vehicle, engine and VIN before ordering.
• WHT001709 is retained as the superseding Volkswagen Group coolant-temperature-sensor O-ring reference for the product record.
• Verify the seal dimensions, sensor interface, coolant flange and VIN before treating it as interchangeable with N90316802.

VEHICLE APPLICATION REFERENCES

• VOLKSWAGEN Beetle
• VOLKSWAGEN Jetta
• VOLKSWAGEN Golf
• VOLKSWAGEN Passat

Model names are reference points only. Production date, engine, market specification and connector changes can affect compatibility.

WHEN REPLACEMENT IS JUSTIFIED

Replacement is reasonable when inspection or workshop testing confirms damage or a functional failure that matches the role of this component. If the evidence conflicts with the product function, continue diagnosis instead of replacing the part.

RELATED PARTS TO INSPECT

• Coolant temperature sensor and retaining clip
• Coolant flange, hose and thermostat housing
• Coolant level, pressure test and nearby sealing joints

VIN CHECK

Confirm fitment using OE number and VIN before ordering.

For fitment questions, share the OEM part number, VIN number, or vehicle information with our team before ordering.

CHECK THE PART AND OE DETAILS

Review N90316802 / WHT001709 product images and fitment details.

WORKSHOP AND BULK ORDERS

Repair shops and distributors can send an OE list, quantities and vehicle information for fitment review and bulk-order support.