
High-quality sealing ring designed to stop leaks at the connection between the water supply pipe and the engine coolant flange.
$3.00
The 058 121 687 O-Ring is a vital seal located between the engine water supply pipe and the cylinder-head coolant flange. This specialized component prevents pressurized coolant from escaping the system where the metal piping meets the composite flange.
Cooling system seals frequently face high pressure and extreme heat, which causes the rubber to harden or swell over time. Because a failed seal leads to coolant loss, replacing this gasket during cooling system repairs is a critical maintenance step.
Maintaining the integrity of the cooling circuit is necessary for engine temperature control and long-term reliability. A leak at the supply pipe connection can cause a steady drop in coolant levels, potentially leading to overheating.
Installing a new 058 121 687 O-Ring whenever the supply pipe is detached ensures a secure, resilient seal. Reusing an old, compressed gasket often results in slow leaks that require a second teardown to correct.
Inspect the rear of the engine for these symptoms of a failing seal:
Pink or orange crusty coolant residue around the flange.
Gradual loss of coolant in the expansion tank.
Distinct sweet odor after driving the vehicle.
Active dripping onto the transmission housing.
Low-coolant warnings on the dashboard.
Perform a pressure test to isolate the leak location. Often, a faulty connection is the culprit when the hard pipe mating surface appears wet or seeping.
OE Part Number: 058 121 687
Function: Seals the engine water supply pipe to the rear coolant flange.
Construction: High-temperature resistant rubber designed for G12/G13 coolant exposure.
Direct Fit: Precision-engineered to match factory pipe dimensions for a secure fit.
Direct Replacement: Swaps easily with the original seal during assembly.
Service Standard: According to ECS Tuning, this part is essential for reinstallation.
Always verify fitment by VIN before ordering.
058 121 687
058121687
058-121-687
058.121.687
| Weight | .02 lbs |
|---|---|
| Dimensions | 2 × 2 × .2 in |
| Mfg Part # | 058121687 |
| Year | Make | Model | Engine | Notes |
|---|---|---|---|---|
| 1997-2001 | Audi | A4 | 1.8L | |
| 2002-2005 | Volkswagen | Jetta | 1.8L | |
| 1998-2005 | Volkswagen | Passat | 1.8L | |
| Audi | B5 A4 | 1.8T | Use vehicle selector to confirm fitment | |
| Volkswagen | Jetta IV | 1.8T | For vehicles with 5-speed automatic transmissions only | |
| Volkswagen | Jetta IV GLI | 1.8T | For vehicles with automatic transmissions only | |
| Volkswagen | Passat B5 | 1.8T | Use vehicle selector to confirm fitment |

The 03L 145 276 is an OE-quality accessory belt idler pulley for select Volkswagen and Audi 2.0 TDI applications. Built to factory dimensions with a sealed bearing, this direct-fit pulley restores correct belt alignment and quiet accessory drive operation — no modifications required.


The 021 103 601B pan is a stamped-steel, OE-style replacement oil sump for select Volkswagen VR6 engines. It restores proper oil containment and lower-engine protection.


Genuine Elring 038121119B Thermostat O-Ring. Prevents coolant leaks and ensures proper operation of your Volkswagen or Audi cooling system.


032121142 Sensor Clip is an OEM-style coolant temperature sensor retainer that supports correct sensor seating and leak-free sealing.


OEM-quality thermostat housing O-ring, OE number 021 121 119 A. Seals the thermostat housing, bypass pipe, and cooling sensor connections.