Changing motor oil regularly is essential for optimal engine performance and longevity. Fortunately, it is a simplified task that a regular car owner can accomplish in under 30 minutes with the right tools and know-how.
However, some issues may arise if you make any slight mistake. A good example is an oil leak from the drain plug after an oil change. Since oil removal is done through the drain plug, you must ensure to remove and install it back securely.
Therefore, we’ll outline the causes, symptoms, preventive measures, and how to fix oil leaks from drain plugs. So, grab a seat and a cup of coffee while you read every word in this article.
Understanding Your Oil Drain Plug: The Engine’s Gatekeeper
Before diving into fixes, it’s essential to understand the role of your oil drain plug. This small but mighty component is crucial for your engine’s health.
What It Is and Why It’s Critical?
The oil drain plug is a threaded fastener, usually a bolt, located at the lowest point of your engine’s oil pan. Its primary job is to seal the oil pan, preventing engine oil from escaping, and to allow for controlled drainage during an oil change.
A properly functioning drain plug ensures your engine retains its vital lubricant. Without enough oil, engine components grind against each other, leading to severe damage and costly repairs.
Common Components Involved
While the drain plug itself is simple, it works in conjunction with a few other parts to form a leak-proof seal.
- The Drain Plug: Typically a steel or aluminum bolt with a specific thread pattern.
- The Gasket or Washer: A crush washer, O-ring, or fiber gasket that sits between the drain plug head and the oil pan. This is often a single-use item designed to deform and create a tight seal.
- The Oil Pan: The reservoir that holds the engine oil. It has a threaded hole where the drain plug screws in.
Understanding these components is the first step in diagnosing why your car oil drain plug leaking might be occurring.
What Causes oil leak from the drain plug?
Oil can leak from your drain plug due to reasons such as a worn or cracked drain plug, a damaged or deformed gasket or washer, an improperly tightened drain plug, or stripped threads on the plug or oil pan.
#1. Worn or Cracked Drain Plug.
Over time, the drain plug can wear out or develop cracks. This can compromise its ability to form a proper seal with the oil pan, leading to oil leaks. It’s important to inspect the drain plug regularly for any signs of wear or damage and replace it if necessary.
#2. Damaged or Deformed Gasket or Washer.
The gasket or washer between the drain plug and the oil pan plays a crucial role in preventing oil leaks.
If this component is damaged or deformed, it may not be able to form a proper seal, resulting in oil leaking from the drain plug. In such cases, replacing the damaged or deformed gasket or washer can help stop the leak.
#3. Improperly Tightened Drain Plug.
If the drain plug is not tightened properly, it can result in oil leaks. The plug needs to be tightened just enough to form a proper seal with the oil pan.
However, care should be taken not to over-tighten the plug, as this can lead to stripped threads or damage to the plug or oil pan.
#4. Stripped Threads.
Stripped threads on either the drain plug or the oil pan can also lead to oil leaks. If the threads are damaged, they may not be able to hold the plug securely in place, resulting in oil leaking from the drain plug.
In such cases, it may be necessary to repair or rethread the damaged threads or replace the affected component.
How To Prevent Oil Leaking From Drain Plug?
#1. Torque it right.
One of the most common causes of drain plug leaks is improper tightening. Over-tightening can strip the threads, while under-tightening leaves a gap for oil to escape. The solution is simple: use a torque wrench.
This tool allows you to apply the precise amount of force specified by your vehicle’s manufacturer, ensuring a secure seal without risking damage.
#2. Fresh crush washer every time.
That little copper or aluminum washer might seem insignificant, but the crush washer plays a vital role in creating a leak-free seal.
It’s designed to deform when tightened, filling any microscopic irregularities between the drain plug and the oil pan.
Never reuse an old crush washer, as it’s already been compressed and won’t provide a reliable seal. Always use a new crush washer with every oil change. They’re cheap and readily available at any auto parts store.
#3. Inspect and replace damaged components.
A damaged drain plug or stripped oil pan threads can make a leak-free seal impossible. Before installing a new drain plug, carefully inspect the threads on both the plug and the oil pan.
Look for any signs of cross-threading, cracks, or stripped threads. If you find any damage, replace the affected part immediately. If you force a damaged plug into stripped threads, it will only worsen the problem.
#4. Cleanliness.
Even tiny particles of dirt or debris can compromise the seal between the drain plug and the oil pan.
Before installing the new drain plug and crush washer, thoroughly clean the mating surfaces on both the plug and the pan.
Use a clean rag or shop towel to wipe away any old oil, dirt, or metal shavings. This simple step ensures a smooth, even surface for the crush washer to seal against, minimizing the risk of leaks.
#5. Combat rust and corrosion.
Over time, rust and corrosion can weaken the oil pan and drain plug threads, making them more susceptible to damage and leaks. This is especially true in areas with harsh winters where road salt is prevalent.
Consider applying a rust inhibitor or undercoating to the oil pan. Inspecting the drain plug and oil pan for signs of corrosion is also crucial for catching potential problems early on.
If you notice significant rust or corrosion, replace that components to prevent future leaks!
What are the Symptoms of an oil leak from a drain plug?
Oil drain plug leak symptoms are quite obvious, like headache symptoms. The common sign of an oil leak from the drain plug is oil puddles underneath the vehicle when packed. And a shortage of oil levels.
#1. Oil puddles.
Like any sign of an oil leak, a common sign of drain plug leaks is oil puddles underneath the vehicle. The puddles may be small or large, depending on how obvious the leak is.
#2. Greasy oil drain plug.
You may not see an oil puddle under the car if you have a small oil leak from the drain plug. Instead, you’ll notice a greasy substance on the drain plug. The greasy substance is a mixture of oil and dirt.
#3. Loose oil drain plug.
Oil puddles underneath the vehicle can emit from other places. And greasy substance on the drain plug can also result from oil leaks from other places. But a loose oil drain plug is a confirmation that something is wrong.
It could mean you have a loose drain plug or a worn crankcase thread. Whatever the leading cause is, you have to fix it ASAP. I know you’ll wonder, how do I stop my drain plug from leaking?
How to fix oil leak from the drain plug?
Here are some steps to help prevent oil from leaking from the drain plug:
Step 1: Confirm the Leak.
Before fixing the problem, make sure the oil is actually leaking from the drain plug.
- Clean the plug and the surrounding area with a rag.
- Start the car and let it idle for a few minutes.
- Turn off the engine and look for fresh drips around the plug.
If oil appears to be coming from higher up, such as around the oil filter or valve cover, the drain plug isn’t the source.
Step 2: Tighten the Plug.
Sometimes, the plug just needs to be properly tightened.
- Use a wrench to gently tighten the plug clockwise.
- Avoid over-tightening to prevent stripping the threads.
- The correct torque is usually between 27 to 40 Nm.
If tightening stops the leak, the process is done. If not, continue to the next step.
Step 3: Replace the Washer.
A damaged or missing washer is one of the most common reasons for oil leaks.
- Place a drain pan under the plug and remove it.
- Let the oil drain completely.
- Remove the old washer and replace it with a new one.
- Reinstall the plug and tighten it to the correct torque.
- Refill the engine with oil and check again for leaks.
Step 4: Check the Threads.
If the oil leaking from the drain plug continues, the threads on the plug or oil pan may be damaged.
- Remove the plug and scrutinize the threads.
- Replace the plug if only its threads are worn.
- Use a thread repair kit (such as a Helicoid) if the oil pan threads are stripped.
- Reinstall the plug correctly to ensure a tight seal.
Step 5: Replace the Plug.
If the plug itself looks worn or doesn’t fit tightly, it’s best to replace it.
- Purchase a new drain plug that matches the vehicle’s specifications.
- Consider using a magnetic drain plug or one with a built-in sealing washer.
- Install it securely without over-tightening.
Step 6: Address Major Damage.
If the oil pan is cracked or heavily corroded, replacing the plug won’t fix the issue.
- Have the oil pan inspected by a mechanic. Drivers can visit a car repair shop in Dubai or any other emirate for professional assistance.
- Replace the oil pan if it’s damaged beyond repair.
How much does it cost to fix an oil leak from the drain plug?
Fixing an oil leak from the drain plug can cause around $35 to $45 if a leaking gasket is a culprit. Technically, it is difficult to say the exact repair cost since several parameters can be the leading cause.
If the culprit is a worn crankcase thread, you’ll need a new crankcase or rethread the hole. This will cause you around $75 to $100. And if the root cause is a loose plug, you won’t spend any money. You only have to retighten the plug.
FAQs.
Q: What can I use to seal the oil drain plug?
Oil drain plug sealant is recommended for sealing oil drain plugs and oil filter leaks. This prevents engine oil leaks and ensures it stays where it is designed to stay (in the crankcase).
Q: Can you over tighten oil drain plug?
Do not over-tighten the drain plug or the oil filter. Doing so will strip the thread. You can also damage the plug’s seal, washer, or gasket, causing oil leaks.
Another reason you should not overtighten the drain plug is that it’ll make it harder for the next service technician to remove it. The process can even make him strip the thread if he’s not careful enough.
Q: Is it OK to use Teflon tape on the oil drain plug?
A Teflon tape is very effective and can prevent leaks on several components. But is it okay to use it on a drain plug?
Using Teflon tape on your drain plug or anywhere in the transmission, power steering, or engine is not advisable. This is because some pieces of the Teflon tape will eventually enter where it’s not supposed to enter and cause damage over time.
You can disagree with me on this. It’s fine. I have colleagues who still use it and haven’t complained about it. But prevention is better than cure.
Q: Can I use silicone on the oil drain plug?
I understand that silicone is oil-resistant but don’t use it on the drain plug. If you use it, it will hold the drain plug, but it’ll eventually fail.
And when that happens, the drain plug will fall out. Imagine if this happens when you’re driving on the highway. It’s a “goodbye to the engine.”
Q: Does an oil drain plug need a washer?
Most drain plugs have seals or washers. If you forget to install them or they are damaged, and you fail to replace them, it’ll cause oil leaks. So, if you don’t mind having some oil leak from the drain plugs, ensure the washers are in good condition.
Q: Are oil drain plug gaskets universal?
Oil drain plugs and gaskets come in different qualities. However, there are some universal drain plugs in the market that will fit in any vehicle. In any case, when shopping for a drain plug gasket, tell the auto store seller the vehicle you want to use it on.
Q: How often should an oil drain plug be replaced?
There’s no replacement interval for a drain plug. The drain plug can last the life of the engine without stripping out or wearing off. However, some drain plug can damage over time and needs replacement.
Ideally, you should only replace the drain plug when it starts stripping off or leaking. However, if it’s leaking due to a lousy gasket or seal, replace the seal, and you’re good to go.
Final Words
Several factors can cause oil leaks from the drain plug. Whenever you notice any of the outlined symptoms above, track the leading cause and proffer a solution. The process can be extremely easy and sometimes hard for a regular car owner.
Follow the instructions above to fix the problem and prevent it from occurring again. However, if the leading culprit is beyond what you can handle, have an experienced mechanic track and fix the problem.