How To Remove A Stuck Oil Drain Plug
There are a few pros and cons of a DIY oil change. For instance, a stuck oil filter is one of the issues that can stump home mechanics. Fortunately, filters usually give way when employing specialty tools, some elbow grease, and tons of patience. Another thing to watch out for is a stuck oil drain plug, especially one with rounded edges that seems impossible to grab with an ordinary wrench. Draining the oil will be next to impossible if the drain plug remains stuck, and the problem can be exacerbated if the oil plug is leaking oil.
Before we proceed, a word of caution here: We're talking about old-school metal sumps and drain plugs, not plastic oil pans with single-use oil drain plugs. For starters, many plastic drain plugs are installed or removed by hand, which means that you shouldn't be able to overtighten them in the same way you could with a tool. We'll be discussing procedures to remove a stuck metal drain plug from an aluminum or metal oil pan, so keep this in mind before moving forward.
Let's start with the basics. A tried-and-true method is to grab a combination wrench and use the box-end to grip and turn the oil drain plug counterclockwise. Remember, lefty loosey, righty tighty is the way to go, because you don't want to further tighten an already stuck plug. Place the box-end of the wrench over the plug and give it a couple of whacks with your palm. With some luck, it should break loose without further drama.
Other methods to loosen a stuck drain plug
Grab a can of PB Blaster or any penetrating oil and squirt some liberally around the drain plug. Soaking the surrounding areas of the drain plug with lubricant helps greatly in ridding it of rust, corrosion, and other nasty stuff that may have contributed to the plug getting stuck. After soaking for about 2 to 5 minutes, grab your wrench and give it a go. If it still doesn't budge, spray more lubricant, allow it to soak, and try again.
If still unsuccessful, you can try something with a longer handle, like a breaker bar or a cheater bar, to give you more leverage. If it still won't turn, try tapping the drain plug with a punch and a hammer or soft mallet, but don't hit it like you're driving a nail through wood. Give it a few gentle taps with the hammer before using the wrench to turn it.
In extreme cases, heating the oil drain plug with a torch might do the job, but be very careful not to burn hoses or other parts near or around the drain plug, and remember to thoroughly clean up any penetrating oil or other flammable liquids before you begin. It doesn't take much heat for the metals to expand and, hopefully, allow you to loosen the plug. Apply steady heat directly to the drain plug, and grab your wrench to loosen it. If you still can't remove the plug, you may need more expensive repairs, and you should reach out to a professional mechanic.
Why does an oil drain plug get stuck?
The oil drain plug can get stuck for the same reasons as a hard-to-remove oil filter, namely, overtightening or neglect. Hand-tightening the oil filter is an age-old method passed down from generation to generation because, well, it works. Of course, you'll need a tool to unscrew the oil drain plug, but there's no need to apply too much force when tightening it. Using a torque wrench is the smartest idea, and most engines require tightening the plug to around 10 to 30 pound-feet of torque, depending on vehicle type and engine size.
Meanwhile, neglect, a lack of periodic maintenance, or simply not changing the oil frequently can result in sludge formation inside the motor. Sludge is contaminant-filled, degraded oil, and its thick, gooey consistency is bad news for bearings, piston rings, oil passages, and everything inside the motor. And since sludge has a rather abrasive texture, it can cause oil filters and drain plugs to become stuck if the threads get contaminated.
Moreover, make it a habit to replace the washer on the drain plug with every oil change. Doing so creates a tighter seal between the plug and oil pan, helping to prevent leaks and other issues. Some drain plugs have one-time crush washers that must be replaced before reinstalling them in the oil sump. No matter the case, replacing the washer is cheap insurance against potential oil leaks and stuck drain plugs.
