An oil drain plug is used for draining oil from an engine. When the engine is in use, the drain plug should not leak. This requires tightening to the right degree. We recommend to use a torque wrench for oil drain plug to ensure accurate tightening. Some Experienced mechanics feel that a torque wrench is not mandatory for an oil drain plug. But they agree on one thing. The drain plug should neither be loose nor too tight. This article will explore how to tighten the drain plug correctly.
Should you use a torque wrench for oil drain plug?
Yes, you can use a torque wrench for a drain plug. It means you’ll not make a mistake even if you tighten it for the first time. Furthermore, a drain plug comes with a special washer for sealing. Other oil pans may come with an O-ring for the same purpose. When tightening the oil plug, the crush washer ensures perfect sealing. But the drain plug should only be secured to the right torque. If it is too loose, oil leaks will follow. At the same time, if you tighten it too much, you can damage the threads. Damaging those threads can be dangerous because of their location.
How do you tighten a drain plug?
When tightening a drain plug, you need to take extra care. Otherwise, you can easily damage the plug or initiate an oil leak. You may need an oil change torque wrench on standby for this. Start by tightening the bolt by hand. Once it feels secure, you may now introduce a torque wrench. Abide by the torque specifications of the manufacturer. Set your torque wrench to the recommended value. You can now tighten the plug gently. As a universal guide, always pull the wrench with two or three fingers. Do not grip it in your hands. This way, you will only stick to the safe torque. Continue tightening until you hear the click sound. By this time, the crush washer could have already crushed to seal the sump. Otherwise, the O-ring could have bulged to seal possible oil leaks.
Can I hand-tighten the oil drain plug?
Yes, you can hand-tighten a drain plug. But you need experience and extra care to do this safely. You also need to remember that not all drain plugs can be hand-tightened. Some of them will not seal perfectly and may loosen over time. At the same time, this cannot crush the washer to provide the needed sealing.
It is also difficult to determine the torque oil drain plugs required without using a torque wrench. The feeling in the hand cannot be reliable. You can easily under-tighten it. That is why most original equipment manufacturers do not support this method. For a particular vehicle, follow the specs by looking at the manual.
Is there a torque spec for oil pan bolts?
Yes, there is a spec for oil pan bolts. Oil pans are made from different materials. Their resistance to shearing, tearing, torsion, and breaking varies. Therefore, the material used dictates the torque spec to be applied. As a thumb rule, you may use 20 to 25 Nm for dura plastic oil pans. If it is an aluminium oil pan, you can use 30 to 35 Nm. The same spec applies if the pan is thermoplastic. This is a general rule for bolts along the sides.
When dealing with corner bolts, they have to be torqued twice same as spark plug torque wrench. While securing the pan, always remember to follow the correct sequence. It is not just the zig-zag pattern that works. Stick to the pattern set out by the manufacturer. At the end of it, the torque will be uniformly distributed, and the pan will be firmly secured.
Can over-tightening the oil drain plug cause leakages?
Yes, overtightening a drain plug can cause leakage. When you apply excessive torque on the plug, you damage the threads. It can even cause the plug to loosen in the end. Attempting to fit it back can worsen the situation and increase the leaks. That is why you should never use an extension, a breaker bar, or some leverage. This can invite over-tightening even with less effort. That is why using a torque wrench for oil change saves the day. You will not have to worry about the possibility of damaging the pan. In extreme cases, overtightening can even cause the threads to be damaged beyond recovery.
Is it normal to leak some oil after tightening an oil drain plug?
Yes, it is usual to see a little oil leak after securing the drain plug. There are cases where the groove of the O-ring keeps some oil. That residual oil will be squeezed out while installing a new O-ring and washer. But this should stop completely after some hours. If the leak continues even after a full day, you need to find where the oil comes from. In such cases, you could be having a leak from another source. Take time to discover where this is coming from and prevent potential faults.
How long will an oversized oil drain plug last?
An oversized drain plug can last years or even the lifespan of your machine. The only key is to install it correctly and securely. Such plugs also dig threads in the parent metal. They could be large, but they still fit in well. That is why they are also self-locking or self-tapping. When installed in a rush, they will cause oil leaks quickly. The whole secret lies in how well you install them.
Conclusion
The manufacturer recommends to use a torque wrench for oil drain plug. Use this wrench and stick to the torqueing procedures. You must abide by the correct torque specs for different oil pans. If you want to do the task in a hurry or with too much torque, you damage the threads. It can cause leakages and unnecessary expenses. Follow the specifications and use the right tools. When pulling on the torque wrench, be gentle. Use your fingers instead of gripping the wrench in your hands heavily