Genuine Mazda Engine Oil Sump Drain Plug Washer • 99564-1400

Genuine Mazda 99564-1400 Engine Oil Sump Drain Plug Washer

Replacement Genuine Mazda engine-oil sump drain-plug sealing washer for Mazda MX-5 Mk2 NB, Mk2.5 NB-FL, Mk3 NC and Mk4 ND/RF models.

The washer fits beneath the head of the engine-oil drain plug and seals against the sump. Tightening the plug compresses the washer to create an oil-tight joint between the drain plug and the sump sealing face.

The washer deforms during installation and should normally be renewed whenever the engine oil is drained. Reusing a previously compressed, damaged or contaminated washer may allow engine oil to seep from the drain-plug area.

One washer is used per engine-oil service, and this listing supplies one Genuine Mazda sealing washer. The sump drain plug, engine oil and oil filter are not included.

• Part type: Engine-oil sump drain-plug sealing washer
• Common names: Sump-plug washer / drain-plug gasket / crush washer
• Mazda catalogue description: Gasket
• Location: Between the engine-oil drain plug and sump
• Function: Seals the engine-oil drain opening
• Quantity fitted: 1 per drain plug
• Quantity required per oil service: 1
• Quantity supplied: 1 washer
• Drain plug included: No
• Engine oil included: No
• Oil filter included: No
• Brand: Genuine Mazda
• Part No.: 99564-1400
• Alternative Mazda format: 9956-41-400
• MX-5 fitment: Mk2 NB, Mk2.5 NB-FL, Mk3 NC and Mk4 ND/RF

Typical reasons for replacement:

• Routine engine-oil and filter service
• Previous washer already compressed or reused
• Oil seepage around the sump drain plug
• Washer distorted during removal
• Sealing face scratched, corroded or contaminated
• Incorrect washer previously installed
• Drain plug removed during sump or engine repair

Fitment advice: This washer is for the engine-oil sump drain plug on the listed MX-5 models. It must not be confused with gearbox or differential drain and filler plug washers, which may use different dimensions and Mazda part numbers.

Other items to consider: Inspect the drain plug threads, plug sealing face and sump threads before refitting. Replace the complete drain plug if its head is rounded, its threads are damaged or its sealing face is heavily corroded.

Useful tools / consumables: Correctly sized six-point socket, ratchet, calibrated torque wrench, oil-drain container, protective gloves, cleaning cloths, replacement oil filter and the correct grade and quantity of engine oil.

Difficulty guide: DIY Difficulty: Easy. The vehicle must be supported safely and hot engine oil handled carefully. Start the drain plug fully by hand to avoid cross-threading the sump.

Why Genuine Mazda? Genuine Mazda drain-plug washers are manufactured to match the original plug diameter, sump sealing face and required compression characteristics. Correct dimensions help create a reliable seal without requiring excessive drain-plug torque.

What’s in the box: One Genuine Mazda engine-oil sump drain-plug sealing washer, part number 99564-1400.

Installation notes: Warm the engine sufficiently to help the oil drain, then switch it off and support the vehicle safely. Position a suitable container beneath the sump and remove the drain plug carefully. Remove the old washer and clean the plug and sump sealing surfaces. Fit the new washer, start the drain plug entirely by hand and tighten it to the applicable Mazda specification using a calibrated torque wrench. Refill the engine with the specified oil, run the engine, switch it off and inspect the drain-plug area for leakage.