Oil Pan Plug Repair – How do you fix the threads?

oil pan plug

The oil pan drain plug is a small threaded bolt, often made of aluminum. It is provided with a seal for tightening.

If the car is new, it does not require much effort to open it, but if the threads are destroyed, there can be many problems.

The causes of many oil pan drain plug problems stem from the materials used. Originally, manufacturers used steel, which is durable, but as demand increased, they chose soft metals like aluminum.

If the seal breaks or the bolt threads are destroyed, oil will leak. Engine oil is necessary to keep moving car parts lubricated. When oil leaks, a lot of friction is created, which later destroys various engine parts.

How to replace the oil pan drain plug

oil pan plug repair

There are those who will opt for a compression stopper, but this causes more problems by destroying the rubber seal. This can work if you have serious leaks, but it is only a temporary solution. When your car comes in for service, you should have the plug replaced.

When you replace the plug, you must place a large container under the drain of the oil pan. This is due to the pressurized oil. As soon as it starts to drain, it slows down.

Try turning the oil pan drain plug. If it bulges, you can continue draining the oil. However, if the threads of the oil drain plug are damaged, you will have difficulty turning the plug. Exert more pressure on the plug and it will eventually come loose.

You can replace your existing oil pan drain plug with a copper plug. When replacing the plug, avoid overtightening, otherwise you will have the same problems as before.

Repair a damaged/stuck oil drain plug

1. New hole

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This is possible if the original oil drain plug is not damaged and the seal seems to be preventing oil leakage. You can drill a new hole in the oil pan and install a new plug and seal. To ensure that the old oil drain plug does not leak, use a self-expanding rubberized oil plug. This should only be done when the oil pan is new and shows no signs of cracking.

Installing a rubberized drain plug is a temporary solution and you should not leave it running for long. Make sure you push it into the oil pan to prevent it from leaking. To ensure that there are no leaks, run the engine at normal operating temperature and check the oil pan again for leaks.

2. Helicoil repair

The Helicoil is a robust steel thread that provides a permanent solution for leaks in your oil pan. It helps to repair damaged shear bolt threads.

3. Repair through TIME-SERT kit

One of the challenges in oil pan drain repair is that it can be costly and time-consuming to replace the entire oil pan drain. The TIME-SERT kit helps you to easily repair aluminum socket bolt threads. It is cheap and fast and you can still keep your oil pan drain. Typically, it takes 30 minutes to repair with the kit.

What size of wrench is required for oil drain plug repairs?

A wrench is a handy tool for loosening and tightening bolts. You position the wrench on the bolt head and turn it either clockwise or counterclockwise. The wrench has a long handle to which you apply torque depending on how tight the bolt is fastened. In some cases, the wrench is supplied with a ratchet handle, which prevents you from having to lift the tool each time. Each screw is a specific size and you will need an appropriate wrench to get the job done.

Sockets are available in the following sizes: ¼ inch, 3/8 inch, ½ inch and ¾ inch. The screw heads can be either a hexagon (6 points), a double square (8 points), or a double hex (12 points). You should select the correct wrench to avoid damaging the bolt threads.

When draining the engine oil, make sure that you first bring the engine to operating temperature. This will allow the oil to drain easily. Determine the correct wrench – usually 3/8 inch – and insert the plug. Next, turn the wrench counterclockwise. The oil will drain perfectly.

How often should you drain your oil?

It often depends on your car and how often you use it. You will often find service instructions in the car manual, but it is recommended that you drain the oil every 7,500 miles or once a year. You should not attempt to drive your car with the same oil for more than 10,000 miles without changing it.

This can cause irreparable damage to the seal and gaskets and at the same time cause the vehicle engine to overheat.

The number of torn off oil drain plugs in the oil pan has increased recently because the steel oil pan has been replaced by an aluminum oil pan. For this reason, you will not find this problem in cars manufactured before 2000. Aluminum has its advantages. Firstly, it is lighter than steel, so your car will weigh a few kilos less.

It is also a better heat conductor than steel, which means that it keeps your engine cooler while it is in the sump. But the problems with aluminum are caused by the increase in damaged bolt threads because people use more torque when opening the bolts.


A leaking oil drain plug should never be ignored, as it can cause the engine to overheat and subsequently destroy the seal and gaskets. If the threads are completely damaged, the oil pan may need to be replaced, which is expensive. If you are traveling and notice the problem, you can use rubber plugs, but they are only a temporary solution.

Other options include replacing your existing plug with a Helicoil or TIME-SERT seal. If your oil pan is new but the oil drain plug seal cannot open, you can drill a hole in the side of the pan and add an additional plug. Make sure there are no visible leaks before driving.

Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. He has also been a motorsport (drifting) driver for over 5 years.