Parts for your 1999 Mitsubishi Pajero-Sump plug washers

1999 Mitsubishi Pajero sump plug washers

Technical sources indicate the 1999 Mitsubishi Pajero is fitted with a sump plug washer (crush washer) as standard. The Mitsubishi Pajero/Montero Service Manual (1997–2004, Group 12A – Engine Lubrication) specifies replacing the drain plug gasket whenever the plug is removed and lists an oil drain plug tightening torque of around 39 N·m. Mitsubishi’s genuine parts catalogue (ASA/EPC) lists the oil drain plug gasket as MD050317 (14 mm aluminium crush washer), with market supersessions such as MU000361 appearing on some listings. Aftermarket guides (e.g., Haynes for Montero/Pajero 1997–2004) echo the requirement to renew the washer at each oil change. So, for 1999 Pajero petrol and diesel variants, a sump plug washer is relevant and used.

The sump plug washer on a 1999 Mitsubishi Pajero does a deceptively important job. It sits between the drain plug head and the sump face, crushing slightly as the plug is tightened to create a leak-tight seal. That soft metal ring (typically aluminium on these Mitsis) evens out tiny imperfections and protects the sump and plug threads from being overworked. Without it, owners often end up chasing annoying weeps or, worse, overtightening the plug and risking thread damage.

For this model, the washer size is commonly the 14 mm ID Mitsubishi type (MD050317 or its superseded equivalents). It’s designed to be a single-use part: once crushed, it won’t spring back reliably. That’s why the factory workshop instructions call for a fresh washer every time the oil’s drained. Sticking with the right size and a quality crush washer keeps servicing straightforward and clean.

Good practice when servicing a Pajero includes cleaning the sump seating face, threading the plug in by hand to avoid cross-threading, then tightening to the specified torque of about 39 N·m. A rattle gun is a no-go here, a torque wrench does the job properly. If there’s any sign of weeping after a change, redoing the plug with a new washer is the fix—cranking it tighter usually makes things worse.

Owners who tour long distances around Australia or New Zealand often carry a small pack of spare washers in the glovebox or tool roll. They’re cheap insurance on trips where a quick roadside oil change or repair might be needed. Aluminium and copper crush washers both work, but sticking with the correct 14 mm Mitsubishi pattern avoids hassles. Replace at every oil change interval (typically 10,000 km or annually, depending on use), and the Pajero’s sump stays tidy and leak-free.

• Use the correct 14 mm crush washer (MD050317 or market supersession).
• Clean mating faces and torque the plug to about 39 N·m.
• Replace the washer at every oil change, don’t reuse a crushed one.

Popular questions

What size sump plug washer does a 1999 Pajero use?
Most 1999 Pajero engines use a 14 mm ID aluminium crush washer, commonly referenced as Mitsubishi part MD050317 (with some markets listing MU000361). Checking by VIN against a parts catalogue is the best way to confirm for a specific engine variant.

How often should the sump plug washer be replaced on a 1999 Pajero?
It should be replaced at every oil change. The factory workshop manual directs replacing the gasket each time the plug is removed so the crush seal can form correctly and prevent leaks.

What torque should the oil drain plug be tightened to on a 1999 Pajero?
Around 39 N·m is commonly specified for Pajero drain plugs of this era. Using a torque wrench and a fresh crush washer helps protect the sump threads and ensures a proper seal.