* Failed PCV (Positive Crankcase Ventilation) system: The PCV system is crucial for venting crankcase pressure. A clogged or malfunctioning PCV valve, hose, or related components will cause a buildup of pressure, forcing oil out the easiest escape route – the dipstick tube. This is the most common and often easiest to fix cause.
* Blocked or restricted crankcase breather: Similar to a PCV problem, a blocked breather (if separate from the PCV system) can lead to the same pressure buildup.
* Severe engine wear: Worn piston rings or cylinder walls allow combustion gases to leak into the crankcase, significantly increasing pressure. This is a much more serious problem requiring a major engine repair or rebuild.
* Head gasket failure: A blown head gasket can allow coolant or combustion gases to enter the crankcase, increasing pressure dramatically. This is a very serious problem, often accompanied by other symptoms like white smoke from the exhaust, overheating, milky oil, or loss of coolant.
* Clogged or failing oil return system: While less likely to cause oil to *blow* out, a restricted oil return passage could contribute to increased pressure, particularly if combined with another issue like a failing PCV system.
What you SHOULD NOT do:
* Ignore it: Continuing to run the engine will likely cause further damage.
* Just add oil: This is a temporary fix at best and will mask the underlying problem, potentially leading to a more expensive repair later.
What you SHOULD do:
1. Stop driving the car immediately. This is crucial to prevent serious engine damage.
2. Check the PCV valve and related hoses: Inspect for clogs, cracks, or damage. Replace the PCV valve as a first step, it's a cheap and relatively easy part to replace.
3. Check the crankcase breather (if separate): Ensure it's not blocked or restricted.
4. Inspect the oil for signs of coolant (milky appearance): This points to a potential head gasket failure.
5. Have a mechanic diagnose the problem: A professional mechanic can properly diagnose the root cause and perform the necessary repairs. Ignoring this could lead to a costly engine rebuild or even replacement.
The oil blowing out of the dipstick is a clear indication of a serious problem. Don't delay getting it checked out; the longer you wait, the more extensive and expensive the repairs will become.
