Parts for your 1999 Mitsubishi Lancer-Sump plug washers

1999 Mitsubishi Lancer Sump Plug Washers

Yes, the 1999 Mitsubishi Lancer uses a sump plug washer. This isn’t a nice-to-have, it’s a specified service item. Technical sources including the Mitsubishi Motors CE/CK Lancer Workshop Manual (1996–2003, Engine Lubrication section), the Mitsubishi ASA electronic parts catalogue, and the Haynes Repair Manual for Mitsubishi Lancer 1996–2005 all list a crush-type oil drain plug gasket for Lancer engines of this era (4G15/4G93/4G94). Mitsubishi’s commonly cited part number is an aluminium crush washer (often referenced as MD050317) for the M14 x 1.5 drain plug. Those documents make it clear: the washer is fitted from factory and is intended to be replaced during routine oil services.

On a 1999 Lancer, the sump plug washer’s job is simple but crucial. When the drain plug is tightened, the soft aluminium (or copper on some aftermarket equivalents) deforms to seal the face of the sump against the underside of the plug head. That controlled “crush” prevents weeping and protects the sump threads by allowing the correct clamping load at the specified torque. Without it, even a tiny imperfection on the mating surfaces can let hot oil seep out, leaving a tell-tale spot on the driveway and risking a low oil level between services.

As part of regular servicing, it’s best practice to fit a new washer at every oil change. The workshop manual specifies a crush washer and a moderate tightening torque, many Mitsubishi listings for CE Lancer quote around 34 N·m for the drain plug. That’s enough to seat the washer without belting the threads. Don’t reuse a flattened or gouged washer, don’t stack old washers, and don’t use sealants or thread tape—none of that replaces the designed crush seal. If you like to keep spares on hand, look for an M14 crush washer with an inner diameter of 14 mm (aluminium is OE-style), and confirm fitment against your VIN if unsure.

A quick wipe of the sump face before refitting, a new washer, and a torque wrench on the plug will keep the Lancer tidy and leak-free. After the service, a brief check under the car once it’s warm—no drips, no worries. If the plug or sump threads feel doubtful, replace the plug or consider a proper thread repair rather than cranking harder.

• Replace the washer at each oil change (or at least every second service if using copper and you’re experienced with annealing).
• Torque the plug to the spec for your exact engine, 34 N·m is commonly cited for CE Lancer listings.
• Inspect for fresh oil mist or drips after the first drive post-service.

Popular questions about 1999 Mitsubishi Lancer sump plug washers

What size sump plug washer does a 1999 Lancer use?
Most 1999 Lancers use an M14 crush washer on an M14 x 1.5 drain plug. The OE-style washer is aluminium with a 14 mm inner diameter. Outer diameter and thickness vary slightly by brand, but common OE-equivalent specs sit around 20 mm OD and 1.5–2.0 mm thick. If in doubt, match your old washer or confirm against the engine code/VIN.

How often should the sump plug washer be replaced?
Best practice is every oil change. The washer is designed to deform once to create a reliable seal. Reusing it can lead to slow weeping, especially after a few heat cycles. If using a copper washer, some techs anneal and reuse, but for most home and workshop servicing, a fresh washer each time is the simplest, cheapest way to avoid leaks.

What’s the correct torque for the sump plug on a 1999 Lancer?
Many CE Lancer listings specify about 34 N·m for the oil drain plug with a new crush washer. Always check the spec for your exact engine variant and use a torque wrench. Overtightening doesn’t seal better—it risks stripping the sump threads or distorting the washer.