Crankshaft Seal Leak – Causes, Symptoms and Fixes!

Knowing what causes a crankshaft seal leak is a crucial query that you may have as a driver, and it is pretty crucial to know how to deal with this situation. If you think there is something wrong with the crankshaft seal, a core component of your vehicle’s engine, you must take immediate action to avoid critical damage in the long run.

Crankshaft Seal Leak

This article will guide you through the telltale signs of faulty crankshaft seals and all the techniques you can utilize to fix them immediately!

How To Identify Causes for Crankshaft Seal Leaks?

To identify causes for crankshaft leaks by checking for mileage and proper installation. Improper maintenance of the engine can be another reason for poor performance. Finally, the issues might be occurring due to being degraded by the passage of time.

Fixing Issues of Crankshaft Seal Leaks

  • Over Time

Like any other engine component, the crankshaft seal undergoes wear and tear with time. This can lead to a gradual degradation in the quality and effectiveness of the seal, causing it to fail eventually. As the engine ages, the crankshaft seal becomes increasingly susceptible to wear and damage due to constant exposure to heat, friction, and other environmental factors.

Over Time Usage of Crankshaft

The oil that circulates through the engine can also contribute to the degradation of the seal, as it contains various contaminants and particles that can wear down the seal over time. When the crankshaft seal becomes worn and damaged, it can no longer effectively keep the oil inside the engine.

  • Poor Maintenance

In addition to age and wear, poor maintenance is another major cause of crankshaft leaks. If you do not perform regular maintenance on your engine, the crankshaft seal can deteriorate at an accelerated pace. Failure to change the oil regularly, using low-quality oil or oil filters, and not replacing worn-out parts can all contribute to premature seal wear and damage.

  • Improper Installation

Installing a crankshaft seal is a crucial process that requires a great deal of care and precision. One of the main reasons a crankshaft seal may not be installed correctly is due to damage during the installation process.

Improper Installation of Car Crankshaft Seal


During installation, a scratched or dented seal may not form a tight seal, leading to oil seepage. Therefore, ensuring the seal is not damaged during installation is crucial. Using the correct tools and techniques to install the seal properly is also important.

Another factor that can cause a crankshaft seal to fail is using the wrong type of seal for your engine. Different engines have different requirements, and using the wrong seal can lead to problems such as oil leakage. Therefore, it’s imperative to identify the correct seal for your engine to ensure it functions correctly. Using the wrong type of seal can also lead to premature wear and tear, causing the seal to fail earlier than expected.
  • High Mileage

If you own a high-mileage vehicle, you must watch for signs of a leaking crankshaft seal. As your engine accumulates more miles, the likelihood of the crankshaft seal starting to leak increases. This is because the seal has been used for an extended period, causing wear and tear on the component. As the seal ages, it may become brittle and start to crack or lose its elasticity, which can cause it to fail.

How To Identify Symptoms of Crankshaft Seal Leaks?

You can identify symptoms of crankshaft seal leaks by checking for small oil puddles forming under the car or smelling something like burning oil, which can be a severe sign. If you are having trouble with engine performance, this might be another symptom.

  • Oil Puddles

One of the most unmissable symptoms of a leaky crankshaft seal is oil puddles forming under your vehicle. These unsightly puddles can lead to oil stains on your driveway or garage floor. The oil leaking from a damaged crankshaft seal can be dark and thick and may even smell burnt.

  • Burning Oil Smell

If you notice a sudden strong burning oil smell coming from the vehicle, it could indicate a severe crankshaft oil leak. When oil leaks onto the engine or exhaust, it can create a distinct smell that is difficult to ignore. The smell can be particularly strong if the leak is significant, as the oil will start to burn on hot engine parts.

Burning Oil Smell from Car

In addition to a smell, you may also see smoke coming out from the hood. This can happen if the leaking oil comes into contact with the hot exhaust system, causing it to burn and smoke. It’s important to take action asap if you notice any of these signs, as a severe leak can lead to engine damage and even a potential fire hazard.

  • Engine Performance Issues

In addition to the symptoms mentioned earlier, a severe leak can also cause damage to other engine components, leading to more expensive repairs down the line. For instance, the oil that leaks out of the seal can damage the timing belt or chain, which synchronizes the movement of the engine’s pistons and valves. If the car’s timing belt breaks, it will cause catastrophic damage to the engine, requiring a complete rebuild or replacement.

Similarly, the oil leakage can also damage the water pump. That is responsible for circulating coolant throughout the engine to prevent overheating. When the engine oil comes into contact with the water pump seal, it can cause it to wear out prematurely, leading to coolant leaks and potential engine damage.

Moreover, the oil that leaks out of the seal can cause damage to electrical components such as the alternator or starter motor. These components are crucial for starting and running your engine, and if they become damaged, it can lead to additional repair costs.

How To Fix Crankshaft Seal Leaks?

You can fix crankshaft seal leaks by getting an immediate replacement to avoid any further issues. You should take the vehicle to a mechanic who can fix and replace the seal. Ensure proper maintenance to avoid problems in the future.

  • Immediate Replacement

Replacing a leaky crankshaft seal is the most effective solution to stop oil from leaking out of your engine. Though it is a common repair, it requires careful attention and expertise to avoid damaging other engine components. It is essential to use the correct seal for your engine and ensure it is installed correctly.

This process involves removing the timing belt or timing chain. Access to the seal often involves disassembling other engine components, such as the harmonic balancer or pulleys. If the seal has caused damage to other components, they may also need to be replaced.

Performing this task yourself can be challenging, requiring specific tools and a good knowledge of your engine’s anatomy. It’s best to have an actual mechanic do this repair, as they will have all the skills and equipment necessary to perform the job correctly. The cost of a crankshaft seal replacement can vary, all depending on the make and model of the vehicle, the type of seal required, and the extent of the total damage caused by this leak.

  • Fixing the Underlying Issues

Regular maintenance and proper installation are keys to preventing future leaks in the crankshaft seal of your vehicle. Neglecting to change the oil regularly or failing to replace worn-out parts can lead to accelerated wear and tear on the seal, which can cause it to leak. Therefore, it is important to carefully follow the manufacturer’s maintenance schedule to keep the vehicle in good condition.

Also, properly installing the seal is critical to ensuring it functions properly and does not leak. This involves using the correct seal for your vehicle and ensuring it is seated properly during installation. If the seal is damaged during installation or the improper seal is used, it can cause a leak.

  • Seeking Professional Help

If you have the required expertise, attempting to fix a leaky crankshaft seal can be safe. A professional mechanic has the proper tools and experience to accurately diagnose the issue and restore your vehicle to optimal performance.

It’s important to remember that simply replacing the crankshaft seal may only sometimes be the solution. By taking your vehicle to a trused mechanic, you can rest assured the car is in good hands. They can provide expert advice on maintenance and repairs and ensure your vehicle runs safely and efficiently.


All in all, you now know that identifying symptoms of a crankshaft seal leak early on can prevent more significant problems from occurring, which is why you need to remain cautious. Once you come to the realization that something is wrong with the seal, it is important to take immediate action, by

following the instructions given in the guide above:

  • Symptoms of crankshaft seal oil leaks include oil puddles, burning oil smell, and engine performance issues.
  • Immediate replacement by a professional mechanic is the most effective solution to stop oil from leaking out of the engine.
  • Regular maintenance and proper installation are crucial to prevent future leaks.
  • Seeking professional help is recommended to diagnose the issue and identify any other underlying issues accurately.

While it is undeniably important to fix any problems, either through your own expertise or with the help of a professional, you must remember to take the proper measures to ensure that this kind of situation never repeats itself. So, if you suspect a leaky crankshaft seal in your car, follow the steps mentioned above with haste to ensure the damage does not get out of hand!

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