Fixing A Stripped Oil Pan Bolt: What You Can Do?

If you've overtightened the oil pan drain plug, it can strip the bolt and make it difficult to remove. In some cases, you may have to replace the oil pan and drain plug. This can happen if you tighten the bolt by turning it clockwise when you intend to loosen it, or if you use the wrong tools to remove and install it, such as an undersized socket or tightening the bolt without a torque wrench. To avoid this, it's important to use the right tools and to make sure you're tightening and loosening the oil pan bolt properly. If you do find yourself with a stripped oil pan bolt, there are several methods you can try to remove it, including using vice grips, a bolt extractor socket, or drilling it out.

What to do if your oil pan bolt is stripped

Assess the damage

If you have a stripped oil pan bolt, the first step is to assess the damage. This will help you determine the best course of action for repairing or replacing the bolt. Here are some things to consider when assessing the damage:

• Check the extent of the stripping: Is the bolt completely rounded off, or is it only partially stripped? If it's completely rounded off, you may need to use a specialty tool like a rounded bolt remover. If it's only partially stripped, you might be able to get a better grip with a larger socket or wrench.
• Inspect the oil pan: Is the oil pan itself damaged, or just the bolt? If the pan threads are damaged, removing the bolt may be more difficult. In this case, avoid using vice grips, as they may strip the head. Instead, use a proper-sized socket with the correct number of sides.
• Evaluate the severity of the damage: Are only a couple of threads damaged, or is the damage more extensive? For minor damage, you may be able to tap the hole in the pan and chase the threads. If the damage is worse, you might need to drill, tap, and install a HeliCoil, or tap, insert a HeliCoil, and cold weld a drain valve into the pan.
• Consider the cause of the stripping: Was the bolt crossthreaded or overtightened? Crossthreading occurs when the plug isn't installed straight and is forced the rest of the way. Overtightening happens when too much force or a power tool is used to screw in the plug. Understanding the cause can help you prevent the issue from occurring again.
• Check for any other damage: Are there any signs of damage or wear on the plug or threads? If so, replace the gasket or washer to prevent the bolt from threading too far in.

Remember, it's important to assess the damage carefully to choose the most appropriate repair method. If you're unsure or uncomfortable with any of the steps, it's always best to consult a professional mechanic.

Apply heat to loosen

If your oil pan bolt is stripped, one method to try and loosen it is to apply heat. This is a last-resort method, and you should exercise caution when attempting it.

First, ensure you have eye protection and are wearing non-flammable clothing. You should also work in a well-ventilated area or set up a fan to help flush out any gas from the heating process.

Next, use a wire brush to clean the bolt, and add some lubricant. Allow this to sit for around 15 minutes.

Now, you can begin to apply heat. Use a propane or MAPP torch, or, for a less aggressive approach, a heat gun. Aim the heat at the bolt head or nut, and heat for around 15 seconds. Do not get the bolt cherry red.

Once you have applied heat, spray the bolt head with water to cool it quickly. Continue spraying until it no longer steams. The expansion and contraction created by this process will crack the rust, so add more lubricant and let it soak in.

Now, try to loosen the bolt using one of the other methods, such as using a wrench or socket.

Use pliers to turn counterclockwise

If your oil pan bolt is stripped, one of the first things you should do is use pliers to turn it counterclockwise. This is because tightening the bolt by turning it clockwise can be what caused it to become stripped in the first place.

To do this, you'll need a pair of clamp or lockjaw pliers, or a pipe or crescent wrench. Position the wrench's jaws around the head of the bolt and tighten them securely. Then, turn the bolt counterclockwise until it comes away.

If you're working in a tight space, a curved jaw will grip the bolt more easily and tightly than a flat jaw. Before you begin, you may want to drape an old towel or cloth around the bolt to avoid scratching it or leaving marks with the wrench.

If you don't have a wrench, a pair of channel lock pliers can also be used to turn a stripped oil pan bolt counterclockwise.

Use a screwdriver to turn counterclockwise

If you have a stripped oil pan bolt, you can try to loosen it by turning it counterclockwise with a screwdriver. Here are some detailed steps to help you through the process:

Get the Right Tools

Firstly, make sure you have the necessary tools to complete the job. In addition to a new drain plug, you'll need a set of vice grip pliers, preferably of the round-jaw variety. Round-jaw pliers can more securely lock onto the bolt, whereas flat-jaw pliers might struggle to get a grip. You'll also need a screwdriver and a hammer.

Loosen the Bolt

Use the vice grip pliers to grab onto the rounded-off drain plug and turn the pliers counterclockwise. If the bolt doesn't move, gently tap the vice grips with a hammer. With a little patience, it should start to turn. If the plug is cross-threaded or the oil pan threads are damaged, you may need to apply more force. Be careful not to strip the head further, as this could cause greater issues.

Pry Out the Bolt

Once the bolt is loose, you can use a flathead screwdriver to pry it out. Wedge the screwdriver between the plug and the vehicle's oil pan and gently turn it counterclockwise. This will help you remove the stripped bolt without damaging the oil pan, which can be an expensive repair.

Install a New Plug

After removing the stripped bolt, it's important to install a new drain plug right away. Thread the new plug into the drain hole carefully, torquing it to the manufacturer's specifications. Check the sealing washer to ensure it is evenly placed around the hole's perimeter for a good fit. Finally, refill the engine with fresh oil and check for any signs of leaks.

It's important to note that if the plug is tightly cross-threaded or the oil pan threads are severely damaged, you may need to use a socket instead of a screwdriver to remove the bolt. Attempting to remove a tightly cross-threaded plug with vice grips could further strip the head and cause more problems.

Drill it out

Drilling out a stripped bolt is a method of last resort, as it is a slow process and there is a risk of damaging the thread inside the housing. However, it is the go-to method if the bolt has sheared off and is now sitting flush with the surrounding surface.

To drill out a stripped bolt, start with a small drill bit, working through the centre of the sheared bolt lengthways. As the bit works its way down the shaft of the bolt, it will heat it, and that heat will help loosen the bolt. The bolt will also have more room to contract when it cools, as its shaft will now be hollow. If you are lucky, a pair of long-nosed pliers will be sufficient to grip the bolt and twist it out. If not, you will need to use a larger drill bit and work through the frozen bolt again.

Hopefully, the bolt will break apart, and you can clear the hole of debris. Be careful not to damage the surrounding thread. If you do need to make repairs, use a universal tap tool.

Drilling a bolt could break it into multiple pieces and leave fragments of metal in the hole. It is a slow process, and you may ruin a few bits in the process. Be willing to part with them. Likewise, a corded drill will make this process easier as opposed to cordless tools.

Frequently asked questions