Water in Motor Oil: What Causes it?

One of the worst possible things that you can find in your oil is water. It typically indicates that there is a crack in the engine block, or (more likely) a leaking head gasket.


How Water Gets in Motor Oil

There are two main ways that water makes its way into the oil system.

  • Normal Engine Operation– It is completely normal for a little oil to enter the engine as it runs or sits. There should NOT be enough water to make the oil look milky. Water can condense inside the engine as it sits. It is also a byproduct of the combustion process.
  • Leak– The two primary fluids that run through your engine are motor oil (which provides lubrication) and anti-freeze (which provides cooling). The engine is designed in a way that these two fluids never come into contact with one another. But, leaks can and do happen.


Symptoms of Water in Oil

As stated above, a little water in the oil is going to happen from time to time. The symptoms of too much water in the oil are:

  • Milky Oil– When you pull your dipstick, you may notice that the oil looks almost orange. This is an indication that water is leaking into the oil pan.
  • Excess Water in Oil Pan– You don’t need to take the oil pan off to check for water, just change the oil. After it sits for a while, the oil and water will separate enough for you to be able to tell that there is water in the oil. Alternatively, if you let the engine sit for a couple of hours, the water will migrate to the bottom of the pan (oil is lighter than water). You can then drain a minor amount of oil. If water drips straight out of the oil pan, you know you have a water problem.
  • Low Coolant– Look at the overflow container of your vehicle. Is it still full? If it is empty, but you can’t find a leak anywhere, that is a strong indication that there is an internal leak.
  • Sweet Exhaust– If you have an unusually high amount of white smoke coming from the exhaust pipes, that can indicate a leaking head gasket. Engine coolant has a sweet smell and taste. That’s why you have to keep it away from dogs. You can often SMELL the coolant coming from the tail pipe. It’s that powerful of a smell.


Water in Oil Causes

Water in the oil will typically be caused by a bad head gasket or crack in the engine block. If not fixed, the water will cause the oil to lose enough viscosity that it’ll seize.

Conclusion: Water in Engine Oil

It’s not very difficult to determine that there is water in the oil. You need to figure out WHY it’s there. Make sure to have the problem fixed right away, or you’ll end up needing a new engine.