Why is Oil Leaking From The Drain Plug and How to Fix it

by Synthetic Oil | Last Updated: September 5, 2022

So you recently replaced the oil in your car and now you are noticing a dark-colored fluid leaking from underneath. If it’s amber, brown, or black, it is most likely oil dripping from the drain plug. This is one issue you will want to take care of as soon as possible. One of the reasons this problem occurs is the drain plug. Why is oil leaking from the drain plug? You’re going to find out. Also, you’re going to learn how to fix it, so let’s get started right away.

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Why is Oil Leaking From The Drain Plug?

Get under your vehicle and do a quick look around. If the oil leak is coming from around the engine area, it could mean you have a drain plug leak. Commonly, the oil drain plug is made of aluminum and is threaded like a bolt. Paired with a sealing gasket, the drain plug is removed whenever you want to perform an oil change. Unfortunately, the thread wears down throughout the years. Some mechanics may also use an impact gun to tighten the drain plug which can result in damage to the pan and the plug.

Some reasons why oil is leaking from the drain plug include:

You won’t know what the issue truly is until you remove the drain plug to either repair or replace it.

How to Fix a Leaking Oil Drain Plug

So you have ascertained that a leaky drain plug is causing those gross stains in the driveway. Aside from that, your engine is losing the vital fluid needed to function. That means you are going to have to nip the leak in the bud. First thing’s first. Ensure your engine is cool before replacing oil or removing your drain plug. From there, follow these steps:

Step 1

If you have a low car, you may have to jack it up a bit to get underneath. Make sure you have a sturdy jack handy and put it in the appropriate areas. The owner’s manual will give you some support area recommendations if you are unsure. Here is a guide to how to safely lift your car.

Step 2

As you usually would when replacing your oil, slide an oil pan underneath the drain plug. This can also help you find the location of the leak if you are uncertain.

Step 3

Grab The right-sized wrench. Start turning the drain plug counterclockwise. In the event the plug turns easily—it shouldn’t—it could be a sign that the plug was simply loose. Tighten it up and see if oil leaks from the plug. Moving the vehicle and placing paper or cardboard under the drain plug and leaving for 6-24 hours will show if the leak has stopped. If you notice that unscrewing the drain plug requires some muscle, it could mean that the seal is beginning or has already failed.

Having trouble getting your oil drain plug loose? Check out our guide on how to remove a stuck oil drain plug for more information.

Step 4

Remove the plug from the oil pan. Look at the drain plug, particularly the threads. Take off the old seal and put on a new replacement if the seal has worn down. Should the gasket or drain plug look defunct, it may be in your best interest to replace the entire plug, not just the washer.

Keep in mind that you are going to have no way to prevent the oil in the engine from running out at this time, so you should have the oil pan aligned properly. Why not change your oil while you are at it?

Step 5

To test whether the drain plug needs to be replaced or if the pan is damaged, do the following: screw the drain plug with a new washer back into the pan. Do not over-tighten it. Should the plug not tighten, it could mean the pan itself has been damaged or you’ve cross-threaded the plug.

Step 6

Inspect the threads next. If the threads are missing, smooth, or flat, you are going to need a new drain plug. If the threads are fine, the problem is the pan. In that case, you are going to need to either purchase a replacement pan or try a self-tapping oil drain plug that is slightly larger than the original.

Step 7

Opted for a self-tapping oil drain plug? Try installing it into the pan. You may have to screw it in halfway and then remove it a couple of times. Depending on the pan, you may also need to drill a slightly larger hole to make the self-taping plug fit better.

Step 8

Now that you have replaced the washer, changed the pan, or used a self-tapping drain plug, the problem should be solved.

Final Thoughts on Leaking Oil Drain Plugs

In most cases, oil leaking from the drain plug is a sign that something is wrong with either the plug or the pan. Stripped threads and old washers are just some common causes. In most cases, you can stop the leakage by plugging up the pan with a brand-new washer or drain plug. It’s a relatively easy fix, so you should have no problems!