Parts for your 2002 Holden Astra-Sump plug washers

2002 Holden Astra sump plug washers — what they do and when to replace them

Technical literature confirms the 2002 Holden Astra (TS/Astra-G) uses a separate sump plug sealing washer. GM/Opel TIS (Engine Oil and Filter Replacement, Astra-G Z16XE/Z18XE/Z22SE) specifies “fit a new sealing ring to the drain plug before installation.” The Vauxhall/Opel electronic parts catalogue lists a 14 x 20 mm sealing ring (GM p/n 11099560) for the drain plug (often p/n 90528145). The Haynes Vauxhall/Opel Astra Petrol 1998–2004 manual likewise states to “always renew the sump plug sealing washer.”

On the 2002 Astra, that little washer is a crush-type seal (usually copper or aluminium) that sits under the drain plug head. When the plug is torqued, the washer deforms to seal the flat face of the sump, stopping weeps and drips after an oil change. It’s a simple, cheap part that does a big job—keeping the oil where it belongs and protecting the alloy sump threads from over-tightening.

Best practice is to replace the washer at every oil change. The material is designed to crush once, reusing it can lead to slow leaks, especially on hot/cold cycles. If there’s a bonded or captive style washer on an aftermarket/magnetic plug, replace the entire plug when the seal looks tired.

Handy service tips for the Astra’s sump plug washer:

• Use the correct size: commonly 14 mm ID x ~20 mm OD crush washer for Astra-G petrol engines.
• Clean the sump’s sealing face and the plug head before refitting—grit can cause weeps.
• Do not use thread tape or liquid sealant, the washer provides the seal.
• Tighten to the workshop spec (typically in the 30–45 Nm range depending on engine). Over-tightening can strip alloy sump threads.
• If the plug’s hex is rounded or the threads look ordinary, replace the plug along with the washer.
• After the first heat cycle, have a quick look for any tell-tale oil misting around the plug.

Signs the washer needs attention include a drip forming on the plug after a drive, oil mist on the back of the sump, or a plug that feels loose without ever feeling “snug” on the torque wrench. Given the cost of a new washer versus the hassle of cleaning oil spots off the driveway, it’s a no-brainer to keep a few on hand and renew one at each service.

Popular questions about 2002 Holden Astra sump plug washers

What size sump plug washer does a 2002 Holden Astra use?
Most Astra TS petrol engines use a 14 mm internal diameter crush washer, about 20 mm outer diameter. It’s the common GM/Opel size listed in the Astra-G parts catalogue. If in doubt, match the old washer or confirm by engine code (Z16XE, Z18XE, Z22SE) before buying in bulk.

Can the sump plug washer be reused?
It can be, but it shouldn’t be. Copper and aluminium crush washers are single-use seals. Reusing them increases the chance of a slow weep. If you absolutely must reuse one in a pinch, keep an eye out for any fresh oil around the plug and replace it at the very next service.

Do I need sealant on the sump plug threads?
No. The washer is the seal. Adding sealant or tape can affect torque readings and isn’t recommended. Just clean the mating surfaces, fit a new washer, and torque the plug to spec from the workshop manual for your specific engine.