What size bolt is a Honda drain plug?
The most common oil drain plug size on Honda engines is a 14mm hex-head with an M14x1.5 thread. However, exact sizes can vary by model and year, so it’s important to verify for your specific vehicle.
Honda’s lineup covers a wide range of engines and production years, from small-city cars to larger SUVs and performance variants. Because drain plug dimensions (head size and thread pitch) aren’t universal across all models, this article outlines the typical sizes you’re likely to encounter and how to confirm the correct bolt size for your car.
Common drain plug head sizes you’ll encounter on Honda engines
Below are the sizes most owners will run into. Always double-check with your model’s service information before buying a replacement.
- 14mm hex head — the standard size on most modern Honda engines for the oil drain plug
- 12mm hex head — appears on some older or less common Honda models
- Special drive types (rare) — a handful of engines may use an Allen or Torx-style drive on the drain plug
These examples reflect typical patterns, but your exact configuration may differ. When in doubt, refer to the owner’s manual or the service manual for your specific model and year.
How to verify the correct bolt size for your Honda
To determine the precise bolt size for your vehicle, follow these steps before purchasing or installing a new drain plug.
- Check the owner’s manual or service manual for the exact drain plug specification, including head size, thread pitch, and torque
- Inspect the current drain plug: measure the head across flats with a caliper or ruler to identify whether it’s 14mm, 12mm, etc., and note the drive type
- Look up the OEM drain plug part number for your engine code (e.g., K-series, R-series) using Honda’s official parts catalog or a trusted parts retailer
- If replacing, ensure the new plug matches both the thread pitch (e.g., M14x1.5) and the head size; avoid mixing incompatible pitches, which can strip threads
- Torque the plug to the specification in your manual, typically in the range of 20–30 ft-lbs for many Hondas, but confirm for your exact engine to prevent leaks or damage
Following these steps helps ensure a proper seal and avoids cross-threading or overtightening, which can harm the oil pan or drain plug threads.
Additional notes on maintenance and compatibility
When replacing a drain plug, it’s a good practice to inspect the oil drain gasket or washer if your model uses one, and replace it if recommended by Honda. Always use the correct oil grade and follow the prescribed service intervals for oil changes to maintain engine health.
Summary
In most Honda engines, the oil drain plug uses a 14mm hex head with an M14x1.5 thread, but there are exceptions by model and year. To be sure, consult the owner’s or service manual, verify the current plug, and match both head size and thread pitch before replacing. Correct torque is essential to prevent leaks and avoid damage to the oil pan or threads.
