For most Acura MDX models, the oil drain plug uses a 14 mm hex head and a thread size of M14 x 1.5, typically sealed with a copper crush washer. This size covers the majority of MDX generations, but always verify against your specific year and engine variant.
Identifying the correct size across MDX generations
The MDX has used the same general drain-plug design across many generations, especially for the common 3.5L V6 engines. While the 14 mm hex head and M14 x 1.5 thread are standard for many models, exact specifications can vary by year and market. To be certain, refer to the owner’s manual or service manual, or inspect the plug directly with the appropriate tools.
Common drain plug size for MDX
Here are the sizes you’re most likely to encounter on MDX models equipped with the typical 3.5L V6 engine:
- Head size (socket): 14 mm
- Thread size: typically M14 x 1.5
- Washer type: copper crush washer
Actual sizes can vary by year and market; always verify before purchase or tool use.
Tools and supplies you’ll likely need
To remove and reinstall the drain plug safely and correctly, gather the right tools and consumables.
- 14 mm socket or open-end wrench
- Torque wrench (to re-tighten to spec)
- Drain pan and rags for catching and cleaning up oil
- New copper crush washer (or the manufacturer’s recommended washer)
- Optional: thread-locking compound is not typically used on drain plugs with washers
Using the correct tools and parts helps prevent stripped fasteners and ensures a proper seal.
Torque and reassembly guidance
When reinstalling, tighten the drain plug to the manufacturer’s specification for your MDX’s engine. For many MDX models with the common 3.5L V6, this is typically in the mid-range of 30–35 ft-lbs (about 40–48 Nm). Always confirm with the official service manual for your exact year and engine, and replace the copper washer to maintain a proper seal.
Common maintenance tips
Quick tips to prevent leaks and ensure a successful oil change:
- Warm the engine slightly before draining to help oil flow.
- Replace the copper crush washer every time you remove the plug.
- After refilling, check for leaks around the drain plug after the first drive.
Following these steps helps maintain a clean seal and reliable engine protection.
Summary
The oil drain plug on most Acura MDX models features a 14 mm hex head with an M14 x 1.5 thread and uses a copper crush washer. While these specifications cover the majority of MDX generations, always verify with your exact year and engine variant using the owner’s manual or service manual, and tighten to the recommended torque when reassembling.