If the engine oil warning light comes on suddenly while driving, it means that there is a loss of pressure in the engine lubrication system. For a combustion engine to work efficiently and regularly, there must be constant lubrication of the moving parts, guaranteed by the circulation of the oil inside the engine itself. It is therefore very important to avoid using any vehicle equipped with a combustion engine that does not have sufficient pressure inside the lubrication system. Driving a vehicle whose engine does not have adequate oil pressure can lead to very serious consequences and extensive damage to the engine block. As soon as your car's oil warning light comes on, it's a good idea to act promptly to save thousands of dollars in repairs.
Steps
Part 1 of 3: Avoiding Mechanical Damage
Step 1. Pull along the roadway, then turn off the engine
As soon as the oil warning light comes on, the first thing to do is look for a safe place to stop the vehicle immediately. Continuing normally with a failing engine lubrication system only dramatically increases the likelihood of serious damage to internal engine components. In these cases, however, your safety and that of all other motorists remain the top priority, so find a safe spot where you can park your car and switch off the engine in total protection without endangering your life and that of others.
- As soon as you can perform this maneuver in complete safety, pull the vehicle over and turn off the engine as quickly as possible.
- The longer the engine runs with insufficient oil pressure, the more likely it is that permanent damage to internal moving parts will occur.
Step 2. Check the engine oil level using the dipstick
After parking your car on the side of the road in a safe place, open the hood of the engine compartment and check the oil level using the dipstick. Locate the latter inside the engine compartment, then carefully pull it out. Clean in the final part where there are the notches relating to the measurement of the current oil level; to do this, you can use a rag or paper handkerchief. At this point, reposition the dipstick in its natural seat, wait a few seconds, then extract it again to be able to check the oil level.
- Observe where the oil level is in relation to the reference marks.
- In the upper part of the last section of the dipstick there is a notch that indicates the maximum oil level (normally, indicated with the words "Max" or "Full", but there may also be no indication), while in the lower part there is the one relating to the minimum necessary level (normally, indicated with the wording "Min", but there may also be no indication). There may also be intermediate notches, in which case each indicates a quantity of oil equal to 1/4 liter.
- If your car's dipstick has intermediate notches and the oil level touches the second notch starting from the one that indicates the maximum level, it means that you need to top up with about half a liter of the same oil in the engine. (this is a general guideline, for more information it is always mandatory to refer to the instruction and maintenance booklet of the car in use).
Step 3. Look for obvious signs of oil leaks
If when you leave you are certain that the oil level was correct, but at the present time it has significantly decreased, it means that there is an oil leak in the engine or, worse, that the engine is burning oil due to a spill. or a leak inside the combustion chambers. Look at the bottom of the vehicle for any signs of oil leakage. If you can clearly see that the lubricant is dripping from the underside of the engine, it most likely means that a gasket has been damaged or that the oil filter is not properly installed in its housing.
- Be very careful because the oil leaking from the engine is most likely still hot.
- If there are no obvious signs of oil leaks and if the lubricant level inside the engine is normal (also considering the portion currently in circulation), there is a good chance that the problem is related to a loss of pressure in the engine. lubrication system.
Step 4. If the oil level is low, perform a top up, then check the status of the oil level again
In this case, it is very likely that it has come on because there is not enough lubricant to keep the system pressure constant. Buy the same type of oil that is currently present in the engine paying close attention to the viscosity grade (5W-30, 10W-30, etc.), then top up the engine oil until the level reaches the dipstick indicator indicating the maximum allowable quantity. Start the engine again to check the status of the oil warning light.
- If the oil check light has gone out, it means that the lubricant level inside the engine was simply too low. At this point, you should try to understand why the problem occurred, but you can still drive safely home or to a garage as the engine compartment inspection found no oil leaks.
- If the oil light is still on, turn off the engine.
Step 5. If the oil warning light is on, do not move the vehicle
If the respective diagnostic light is still on after refilling the lubricant, it means that the problem is related to the oil pressure inside the engine and not to the lack of lubricant. The engine component that oversees oil pressure is the oil pump, whose job is to keep it constantly circulating within the lubrication system while the engine is running. If the oil pump malfunctions, the engine is no longer properly lubricated, which can cause serious damage.
- If the oil warning light stays on, you need to call a tow truck to have the vehicle towed to the nearest garage or home.
- If possible, do not drive the car when the oil warning light is on.
Part 2 of 3: Coping with an Oil Leak
Step 1. Put on the proper safety gear
Before carrying out any type of maintenance or work on a vehicle, it is always necessary to wear the safety equipment appropriate to the situation. Checking for an oil leak from a vehicle's engine means visually and physically checking its undersides, where the oil will drip from the top. In this case it is therefore essential to wear a pair of protective goggles to protect the eyes. It may also be helpful to wear gloves to protect your hands from scratches, bumps, or the heat radiated from the engine.
- To carry out these checks safely, it is necessary to wear a pair of protective goggles that protect the eyes from irritants in an engine compartment.
- Wearing safety gloves is not mandatory, but it is highly recommended over working with bare hands.
Step 2. Disconnect the car battery from the electrical system
Before lifting the vehicle, open the engine hood and disconnect the battery cables to make sure the engine cannot accidentally start while you are inspecting the bottom of the car. Use a spanner or socket wrench to loosen the nut securing the black electrical wire to the negative pole of the battery. The negative pole of a car battery is the one connected to the black electric cable and is identified by the "-" symbol.
- Disconnect the black cable from the negative pole of the battery, then secure it to one side of the battery.
- It is not necessary to disconnect the electric cable of the positive pole as well.
Step 3. To lift the vehicle, you can use an ordinary jack, then use a pair of steel jack stands to secure the car
Make sure your vehicle is parked on a solid asphalt or concrete surface, then jack it up with a jack so you have enough room to get under the car and inspect the bottom. When the vehicle has reached sufficient height, place a pair of steel jack stands along the support points of the frame to hold the car in place should the jack fail.
- Never use the jack alone to hold the car up while inspecting the underside.
- If you do not know where to fix the jack or the support stands, check the instruction and maintenance manual of the vehicle where the exact points in which to place these tools are indicated.
Step 4. Look for obvious signs of an oil leak
Carefully inspect the underside and sides of the engine for possible lubricant leaks. This may be a small gap that allows oil to escape only when the engine is running or has reached ideal operating temperature. In other cases, the loss may be immediately evident. Because the engine lubrication system is under pressure, a large oil spill results in a large amount of lubricant all around the area where the problem occurred.
- If you see a small trickle of oil running along the outer surface of the engine, you should follow it back up until you find the source of the leak.
- If you can clearly see a large amount of oil spread all over the place, it means that the leak is considerable.
Step 5. Make sure the traces of fluid you found are engine oil
Modern engines have different types of fluids in them and it can be difficult to determine what it is when you spot a fluid leak. Engine oil is generally brown or black in color, while coolant tends to be orange or green, and window cleaner should be blue. However, when a leak occurs, the liquid mixes with the debris and dirt normally found in the engine compartment, making it difficult to determine its nature from the color. Collect a small amount of fluid using a white sheet of paper to get a clear idea of what it is.
- Before proceeding with this type of check, make sure that the engine is completely cold to avoid the risk of burning yourself with hot liquids.
- When looking for an oil leak, focus on trying to locate a viscous liquid that is brown or black in color.
Step 6. Check where a leak is normally most likely to occur
When looking for a possible oil leak, it's best to start the job by inspecting the seals for damage. The combustion engines of ordinary cars are the result of the assembly of several pieces. These components cannot be simply bolted together because they would not provide a sufficient seal to hold the oil under pressure. It is for this reason that car manufacturers resort to the use of special gaskets to adequately seal the various engine components. If one of these seals fails, the pressure in the lubrication system causes the oil to escape at its weakest point, thus creating a visible leak. While it is usually best to check the engine seals first, it is not enough to have a complete and exhaustive diagnosis of all the places where an oil leak could occur.
- Look at the area where the bolts are that secure the oil pan to the bottom of the engine block. The oil pan is located at the lowest point of the engine, to which it is fixed by a series of bolts. Run your fingers along the edges of the oil tank to identify where the leak may have originated.
- Check the oil pan drain plug to make sure it is tight and that there are no noticeable fluid leaks.
- Check for signs of oil leaks along the gasket that seals the cylinder head to the engine block and along the top of the engine, exactly above the cylinders where the valve cover is attached.
- Lubricant may also leak from the bolts securing the pulley to the crankshaft located at the bottom of the engine block.
Step 7. Replace faulty seals causing oil leakage
Once you have identified where the leak originates, you need to take the necessary steps to stem and fix the problem. Locate the leak, then disassemble the part of the engine where the gasket to replace is located. Remove any residue from the old gasket before replacing it with a new one and reassembling everything. Some gaskets are very simple to replace, while others may require hours of work and removal of the engine from the vehicle. See if you can fix the problem yourself or if you need a professional mechanic.
- If you have been able to locate the leak but do not have the tools or the proper preparation to fix the problem, it is best to take the vehicle to a professional mechanic and explain to him in detail what you have been able to discover.
- You can buy engine gaskets at any auto parts store.
Part 3 of 3: Assess for Other Lubrication System Problems
Step 1. Replace the oil filter
If it has been a long time since you last changed the engine oil, it is possible that the filter has become clogged, preventing the lubricant from flowing freely and properly through it. The solution for this type of problem is to completely drain the engine lubrication system of used oil, replace the filter and add new oil. If the problem was the old oil filter not allowing the lubricant to flow freely in the oil filter, its indicator light should go out as soon as you start the engine after replacing the filter and restoring the correct pressure level.
- If the oil warning light does not come on and the lubricant pressure indicator detects a normal value, the problem has been solved.
- Conversely, if the oil warning light stays on, stop the engine immediately.
Step 2. Check the compression level of the engine
If the oil level inside the lubrication system is below normal, but you have not experienced any leaks, it means that the engine is most likely burning oil. In a properly functioning engine, the oil should not be able to enter the combustion chamber along with the mixture of air and fuel. If the engine burns oil, then it means that the seal of the combustion chamber has been compromised, allowing the lubricant to penetrate inside. The two critical places where this problem commonly occurs are the valve guides and the rings that line the pistons (also called piston rings). If these components are so worn that the oil can enter the combustion chamber, there will also be a drop in the level of compression generated by the relevant piston.
- Purchase a pressure gauge specifically designed to measure the compression level of an engine. This tool must be positioned in the seat where the engine spark plugs are mounted. You will need to take a measurement for each of the cylinders.
- You need a friend to help you by cranking the engine while you read the maximum reading on the gauge.
- If one of the cylinders reads lower than the others, the piston rings or valves have a problem. In this case the engine requires a complex and demanding repair.
Step 3. Check the sensor that measures the oil pressure
Locate the location where the oil pressure sensor is installed, then disconnect the electrical wires that power it. At this point, check if this step has had any effect on the current value of the oil pressure detected by the specific gauge of the car. If not, it means that most likely the problem is not related to the oil pressure, but simply to the sensor that measures it.
- To locate the oil pressure sensor, consult the vehicle's instruction and maintenance booklet, as depending on the make and model of the car it may be located in different places in the engine compartment.
- If the oil pressure gauge does not move when its sensor is disconnected, the pressure inside the lubrication system may actually be correct.
Step 4. Replace the oil pump
Technically, this component is not responsible for the oil pressure inside the engine as it simply makes the lubricant flow. It is the resistance encountered by the oil as it flows within the forced path of the lubrication system that generates the pressure. With this in mind, a faulty oil pump reduces the engine's ability to create the correct pressure within the lubrication system. If you have chosen to replace the oil pump yourself, make sure you purchase the correct seals, otherwise you could cause a large amount of lubricant. Installing a new oil pump can be a complex project, so unless you have all the tools and skills you need, it may be more sensible and safer to hire an experienced professional.
- Use the correct tools to install the oil suction tube into its seat on the pump. Forcing it to graft could cause serious damage.
- Before installing the new pump, it must be filled with oil, so that when the engine is started for the first time, it is ready to suck the liquid from the sump without idling and risking blocking or damage.
