Parts for your 1987 Mitsubishi Pajero-Sump plug washers

1987 Mitsubishi Pajero sump plug washers

Yes, the 1987 Mitsubishi Pajero uses a sump plug washer. Technical sources that note this include the Mitsubishi Pajero (L040/L140 series) Factory Service Manual in the Engine Lubrication section, which calls for the drain plug gasket to be renewed at oil changes, the Mitsubishi ASA/EPC parts catalogue, which lists a “gasket, drain plug” for this model range (commonly the M14 gasket, e.g., MD050317, used across Pajero engines of the era such as 4G54 and 4D56), and workshop guides like the Haynes Mitsubishi Pajero/Montero manual (1983–1996), which advise fitting a new sealing washer whenever the plug is refitted. Taken together, these sources confirm the washer is a standard service item on this vehicle.

On a 1987 Pajero, the sump plug washer sits between the sump’s sealing face and the plug head. Its job is simple but critical: provide a crushable, oil-tight seal that prevents weeping after an oil change. Over time, the washer work-hardens or deforms, so reusing it can cause slow leaks, messy underbodies, and misdiagnosed “rear main” leaks. Copper and aluminium crush washers are most common, with fibre options seen less often.

Best practice for servicing is to replace the washer at every oil change. A typical fitment is an M14 sealing washer sized for the Pajero’s OEM drain plug, genuine and quality aftermarket equivalents are widely available. When changing oil: clean the sump face and plug threads, install a fresh washer, start the plug by hand to avoid cross-threading, then tighten to the torque specified for the engine variant in the factory manual—don’t just “give it a heave” with a long breaker bar. After the refill, run the engine, let it sit a few minutes, and check for any seepage around the plug.

• If caught short, a copper washer may be temporarily reused after annealing (heat to dull red and quench) to restore softness—but that’s a stopgap, not a regular habit.
• Watch for tell-tales like oil mist on the sump’s trailing edge, spots on the driveway, or a washer that’s visibly flattened or grooved—these all point to replacement time.
• Avoid mixing materials, match washer type and size to the plug and sump to protect the alloy sealing face and maintain the correct clamp load.

Popular questions

What size sump plug washer does a 1987 Pajero use?
For most 1987 Pajero engines (such as the 4G54 petrol and 4D56 diesel), it’s an M14 drain plug with a matching crush washer. Genuine parts catalogues commonly list the Mitsubishi drain plug gasket under numbers like MD050317 for this era. Always confirm against the engine code and chassis number to ensure the correct inner diameter and outer diameter.

Can the sump plug washer be reused?
It’s not recommended. The washer is designed to deform once to create a reliable seal. Reusing can lead to weeping or leaks. If absolutely necessary in a pinch, a copper washer can be annealed to soften it, but the proper approach is to fit a new washer at every oil change.

How tight should the sump plug be on a 1987 Pajero?
Tighten the plug to the torque specified in the Mitsubishi Factory Service Manual for the specific engine—over-tightening can strip threads or distort the washer, and under-tightening can cause leaks. If a torque wrench isn’t available, snug the plug after seating the new washer and then add a modest, controlled turn, avoid excessive force.