What To Do When The Oil Light Comes On: Quick Guide

Taking Action: Responding to the Oil Light

Seeing the oil light illuminate on your dashboard can be a nerve-wracking experience for any driver. This small, red light is a warning signal that should never be ignored, as it indicates a potential issue with your vehicle’s lubrication system. In this article, we’ll walk you through the steps to take if the oil light comes on, the possible causes, and how to prevent it from happening in the future.

What Does the Oil Light Mean?

The oil light on your dashboard comes on when engine oil pressure drops below the minimum pressure needed to safely operate your engine.

What to do when your oil light comes on

• Pullover immediately, shut off the engine, and turn on your hazard warning light.
• Check the oil level on the dipstick

If your oil level  is below the minimum markings, call roadside assistance or a friend to bring you more oil. Read the oil fill cap on your engine to find the correct oil to request. However, if your friend can’t find that particular oil, adding the wrong oil is better than running your engine with low or no oil.

Do NOT continue to drive. Driving with the oil light on can destroy your engine, costing you thousands!

If you can’t get someone to bring you oil, CALL A TOW TRUCK. A tow will be much cheaper than the cost to replace your engine.

There are two kinds of oil lights: an oil pressure light and an oil level light. Most vehicles only have an oil pressure warning light.  Usually, only luxury cars have both. Unless you know for sure that your car has an oil level light, you should assume yours is an oil pressure light. When the oil light comes on, it means your engine oil pressure has dropped to less than 7-psi. and continuing to drive can destroy your engine. So pull over immediately and shut off the engine.

If your oil light comes on but the oil level is good

• Your oil pump is worn out and can’t produce enough pressure
• The oil pressure relief valve is stuck open and is dumping all the oil pressure back into the oil pan
• The oil pressure sensor or the wiring to the sensor is faulty, and you’re getting a false low oil pressure warning

Common Causes of the Oil Light Coming On

Understanding the potential causes of the oil light coming on can help you diagnose the issue and determine the best course of action. Here are some common reasons:

Low Oil Level: All engines burn some amount of oil. With modern extended oil changes, where you can drive up to 10,000 miles between oil changes, it’s not uncommon to burn oil between changes to the point where your engine runs low on oil and the oil light comes on. Regular oil level checks can help you stay on top of this and prevent the oil level from dropping too low.

Oil Leak: A leak in the oil system can cause the oil level to drop, triggering the oil light. Look under your vehicle for any signs of oil puddles or drips. Common places for leaks include the oil pan gasket, valve cover gasket, and oil filter.

Faulty Oil Pump: The oil pump is responsible for circulating oil throughout the engine. If the pump fails, oil pressure will drop, causing the oil light to come on. A faulty oil pump is a serious issue that requires immediate repair.

Worn Engine Bearings: In some cases, worn engine bearings can cause a drop in oil pressure. As the bearings wear down, the clearance between them and the crankshaft increases, reducing oil pressure and potentially triggering the oil light.

Faulty Oil Pressure Sensor: Sometimes, the oil light may come on due to a malfunctioning oil pressure sensor rather than an actual issue with the oil pressure. However, it’s important to have this diagnosed by a professional to rule out more serious problems.

How to determine if you have a bad oil pressure sensor

Rent an oil pressure gauge and an oil pressure socket from an auto parts store. Disconnect the electrical connector to the oil pressure sensor and unscrew the sensor. Screw in the fitting for the oil pressure gauge. Then start the engine and read the gauge to see if it’s at least 7-psi and rises as you increase engine speed. If it does, replace the sensor. If it doesn’t, you have more serious problems like a bad oil pump, stuck oil pressure relief valve, or crankshaft bearings.

Worn bearings usually only cause the oil light to come on at idle

Worn crankshaft or camshaft bearings can cause low oil pressure. That causes the light to come on when idle when your RPMs are low. But the light often goes off as you increase RPMs. A shop can test bearing wear by removing the oil pan and using Plastigauge to measure bearing clearances and bearing condition.

Worn crankshaft bearings cause low oil pressure. The severely worn bearings and scored crankshaft journal in this picture are caused by lack of normal maintenance. This engine must be rebuilt or replaced.

©, 2021 Rick Muscoplat