Here's why:
* Oil Pump and Pressure: When the engine is idling (stopped), the oil pump may not be generating enough pressure to adequately lubricate all engine components. The increased engine speed during acceleration increases the oil pump's output, temporarily restoring sufficient pressure.
* Possible Causes: Several things can cause low oil pressure:
* Low Oil Level: This is the most common cause. Check your oil level immediately using the dipstick. If it's low, add oil of the correct type and viscosity (check your owner's manual).
* Oil Pump Failure: The oil pump itself might be failing to circulate the oil effectively. This is a serious mechanical problem requiring professional repair.
* Worn Engine Bearings: Worn bearings allow oil to leak past them, reducing pressure. This indicates significant engine wear.
* Clogged Oil Filter: A clogged oil filter restricts oil flow. Replace the filter.
* Leaking Oil Seals or Gaskets: Oil leaks reduce the overall amount of oil available for lubrication, affecting pressure.
* Thick Oil: Using oil that's too thick for the temperature can also contribute to low pressure.
What to do immediately:
1. Do not continue driving. Driving with low oil pressure can cause catastrophic engine damage, including seizing the engine.
2. Check your oil level immediately. If it's low, add the correct type and amount of oil (consult your owner's manual).
3. If the oil level is fine, or if the light comes back on after adding oil, DO NOT DRIVE the car. Have it towed to a qualified mechanic for diagnosis and repair. Ignoring this could result in very expensive engine repairs or replacement.
Low oil pressure is a serious warning sign. Prompt attention is crucial to prevent significant and costly engine damage.
