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Car Oil Leak Causes

So you see a dark patch appear under you car engine whenever it is parked for a while or you hear a loud screech when the engine is running. These are all symptoms of possible Oil Leak.


How to locate an Oil Leak.


Screeching noise with engine running?

Screeching noise when the car is running is caused by oil on the belts. The oil causes the belts to slip which creates the noise. Common places to look for these kind of oil leaks:
  • Valve Cover Gasket at top of engine - This gasket wears out often and needs to be replaced. When it leaks, oil escapes from the top of the engine onto the belts.
  • To fix - Valve Cover Gasket Replace

  • Crankshaft Seal at side of engine - It is behind the main pulley that the belts run on. There is also another Crankshaft seal that is hidden by the Transmission. These are difficult to replace. The seal behind the main pulley requires that the main pulley be removed to replace the seal. This pulley is on very tight and if the pulley does not have much room around it, it is very hard to remove. Seal beside the Transmission needs the Transmission to be removed to access it. When it comes to Crankshaft Seals it is usually easier to get a mechanic to work on them.
  • Your vehicle may have either a Timing Belt of Timing Chain. For vehicles with Timing Chains, the chains are covered in Oil and the cover stops the oil leaking out using a Timing Cover Gasket. When the Timing Cover Gasket goes bad, Oil escapes out the side of the Timing Cover. For cars with Timing Belts, they do not get covered in Oil and they have an extra Oil Seal on the Camshaft. When the Camshaft Oil Seal goes bad it lets oil escape onto the Timing Belt and shortens its life - causes it to break when not expected damaging the engine. For Camshaft Seals, the Timing Belt will need to be removed and if not re-installed correctly, the engine can be destroyed. Timing Chain cover gaskets can sometimes be easy to replace - depending on access to the engine. Other times the main pulley has to be removed to allow the Timing Cover Gasket to be replaced. This is another job that can be best left to a mechanic.
  • Oil that appears at the bottom of the engine can come from many different sources including the ones just mentioned.


    Black or brown patch of liquid under the car.

    An oil patch under the car can be caused by the oil leaks above or by the ones listed below:
  • Oil Pan - This is a common place for oil to leak out as the gasket for the Oil Pan wears out. The Oil Pan is located at the bottom of the engine.
  • Oil Pan Gasket Replace

  • Drain Plug - Sometimes the bolt in the Oil Pan that is removed when changing oil is not put back correctly and this causes oil to leak out.
  • Oil Pan Drain Plug


    Wherever the Car Oil Leak is coming from, a dye can be added to the engine oil to make it easier to see the location of the Car Oil Leak. After the dye is added to the engine oil, the engine is run for a little bit to pump the dye to the location of the leak. Using a special light, the trail of the dye can be seen on the engine and then the source of the Car Oil Leak discovered.

    Check out these other leaks for additional information on Car Oil Leaks:
    Car Oil Leak 8 Reasons 

    Engine Oil Leak

    Car Oil Leak

    Car Oil Leak, Engine Oil Leak, Oil under car







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