Repair Services

058 121 687 – Sealing O-Ring (Priced Each)

High-quality sealing ring designed to stop leaks at the connection between the water supply pipe and the engine coolant flange.

$1.05

  • Description
  • Additional information
  • Fits These Cars

Description

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.

Why the 058 121 687 O-Ring Matters

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.

Signs Your Sealing O-Ring Needs Replacing

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.

Key Features

  • 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.

Compatibility & Applications

Always verify fitment by VIN before ordering.

Cross Reference Numbers

  • 058 121 687

  • 058121687

  • 058-121-687

  • 058.121.687

Additional information

Weight .02 lbs
Dimensions 2 × 2 × .2 in
Mfg Part #

058121687

Year Make Model Engine Notes
1997, 2001 Audi A4 1.8T
2000, 2005 Volkswagen Jetta IV 1.8T
1998, 2005 Volkswagen Passat 1.8T
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