BMW 640i Smell of oil in car Inspection at your home or office.

Common reasons for this to happen:

• Oil Leak: An oil leak will drop oil onto the exhaust system, which will create a burning oil smell in the cabin of the car. The smell might be even more noticeable outside of the car. Oil leaks can happen in a number of different locations in the engine. A suspected oil leak should be inspected and repaired immediately.

The best way to verify an oil leak is to keep a close eye on the oil level on the dipstick. If it is going down on a daily or weekly basis, there is a leak somewhere in the system.

• Poorly Done Oil Change: An oil change that is not done properly can result in excess oil dripping onto the exhaust system or other engine parts. As the engine heats up the oil will burn off creating a pungent oil smell in the car. If there are no additional leaks the oil will burn off completely and the smell will disappear after a few days.

• Loose Oil Filter: Oil filters operate under pressure and if they are not installed correctly or are shaken loose due to driving on a rough road (this is not common) they can spray oil around the engine. As the oil burns off, the smell of oil will fill the car. A puddle of oil under the vehicle is another symptom of a loose oil filter. This problem should be addressed immediately as eventually the engine will be drained of oil.

• Leaking or Damage Oil Plug: The oil pan has a plug in it and if it is damaged or loose it can leak. If the leaking oil lands on the exhaust system it can produce the smell of burning oil. This will also create a pool of oil on the garage floor when the car is parked. Again, this issue should be repaired immediately so the engine does not run out of oil.

• Failing Gaskets: Many oil leaks can be traced back to degraded or failing engine gaskets, oil seals or leaking and bad connections. There are numerous gaskets scattered throughout the engine. Common gaskets that fail are valve and oil pan gaskets.

Gaskets usually fail due to the engine heat causing them to harden and shrink. The older the engine, the more likely it will have leaking gaskets. A gasket or seal leak should be inspected and repaired immediately.