How To Bypass Low Oil Sensor On Generator ?

Before you learn how to bypass low oil sensor on generator, you need to be aware that this solution is applicable only for situations where the sensor is triggered unnecessarily. You should not make this method a way to run your generator constantly by avoiding the safety feature. If you notice that there is a problem with the generator, you should get it repaired. However, in case of an emergency, you can follow the method given here to bypass the generator’s low oil sensor.

Safety Precautions

It is important to be careful when handling generators, especially since they generate electricity. So, you should read and understand the instructions given in your user manual before you work on the low oil sensor. Here are some safety precautions that you should adhere to.

  • Make sure that the generator is turned off before you try to bypass the low oil sensor in order to prevent any risk of injury. Do not attempt to do anything while the engine is still running or when the power is on. 
  • Always beware of any moving parts of the generator. If the generator has been just turned off, parts of the engine may still be moving and you shouldn’t touch them. So you should wait for 5 – 10 minutes after turning off the power before touching anything.
  • Similarly, you need to make sure that the generator has had a chance to cool down once you turn it off. Certain parts of the generator will be even hot enough to burn you. 
  • The other important thing to be aware of is that the fuel is highly flammable, especially gasoline and propane. Do not allow any cigarettes, electrical sparks, and open flames near the fuel and any part of the engine in contact with the fuel.

How to Bypass Low Oil Sensor on Generator

Bypassing a low oil sensor is an easy task if you follow the steps accordingly. Here’s what you need to do to restore the function of your low-oil sensor.

  1. Make sure that you have read the safety instructions correctly. Locate the low oil pressure switch.
  2. You will find a yellow wire that can be removed from the switch easily. Regardless of the brand of your generator, the wire should be yellow and often found on the crankcase near the oil fill cap under the panel.
  3. There will be a green or some other colored connector on the yellow wire. Pull it to disconnect the wiring and tape that wire so that it will not touch the ground.
  4. Since this wire is removed, now you cannot turn on the switch to turn off the ignition. So, you can start the generator and the low oil sensor will not prevent it from starting.
  5. Once the generator has started, let it run for 15 – 30 minutes. This will warm up the oil and its viscosity will change. This will help release the oil sensor stuck at the bottom of the crankcase.
  6. After you make sure that the sensor is not stuck anymore, you should reattach the wire to the switch that you disconnected previously.

If you find any further trouble after this, then there could be a fault with the sensor itself. So, you need to replace the oil sensor completely to restore the function. For this, you should contact the manufacturer or get advice from your technician. If not, check the website or store to see whether they sell replacement parts. It is important to solve this problem quickly or else you risk damaging the other parts of your generator as well.

What Causes Low Oil Pressure?

It is important to know what causes the low oil sensor to malfunction so that you can prevent it from happening again. Some repairs could be very cheap while others can be quite costly. The main reasons behind low oil are machine failure and lack of lubricant. However, there are certain other reasons for this such as the ones indicated below.

Not Enough Oil

Although you add a generous amount of oil to the generator, it may not always go into the generator. It might get burned up by the piston rings or even leak through the oil plugs and seals. This usually happens when your generator is old. You can try adding more oil, but if it is leaking, it will not solve the problem. Find the leak and repair the part before you add more oil. Regular inspection of your generator and maintenance will help avoid issues like this.

Low Pressure

If you have a diesel generator, the pressure gauge shows real-time indications of the generator condition. Some manufacturers make oil with a lower viscosity than the recommended SAE grade. The lesser the number, the lower the pressure of the lubricant will be. So if the pressure is within the normal range, you don’t need to worry. 

Engine Wear

You need to consider the age of the generator when dealing with oil issues. Check the oil level of your generator on the dipstick. If it is between the “add” and “full” lines, the low pressure should be due to worn-out engine bearings. This is a common issue when the generator is used for a long time. Excessive use of the generator reduces the flow restriction and drops the oil pressure. If this is the case with your generator, it’s time to consider purchasing a new generator.

Defective Oil Pressure Gauge

You should also check the accuracy of the pressure gauge. Check the oil levels when the oil pressure warning light turns on. If the oil level is safe and there are no strange noises or high temperatures, there could be a problem with the sensor itself. Check everything again, and if there is nothing wrong with the oil level, you can replace the oil pressure sensor. If the warning light stays even after you replace the sensor, then you should replace the oil pump.

Clogged Filter

A clogged filter can also lead to oil issues in a generator. The bypass valve will not work well if the filter gets contaminated with debris, water, and soot. This leads to lubricant starvation which is a major problem for the generator. Overextended oil is the reason behind a clogged filter. If the bypass valve is not functioning properly, it could be due to a faulty filter.

Wear and Tear

If the oil level on the dipstick is between the low and full marks and if the engine is very loud when running, the problem could be in the oil pump. If the pump is old and worn out, it will not serve its function correctly. Replacing the oil pump will solve the problem, and it will even make the engine run quieter again. The moving components of a generator undergo wear and tear over time. These issues related to the oil sensor could be signs that your generator is reaching the end of its useful lifespan.

Frequently Asked Questions

How Does Oil Sensor Work on a Generator?

The low oil sensor functions as a safety measure in the generator. It detects the low oil level through an oil pressure switch or an oil pressure sensor. Then it alerts the engine operator about the low oil level. Some generators often come with an automatic shutdown mechanism to prevent the generator from running with low oil and causing harm.

How to Test Low Oil Sensor on Generator?

  1. Place the generator on a leveled surface and remove the oil dipstick located at the bottom of the engine to check the oil level. You should add more oil as needed according to the level of oil.
  2. Then disconnect the wire coming from the engine oil switch.
  3. Turn on the ohmmeter and set it to the lowest setting. Place the positive probe of the ohmmeter on the connector of the engine oil switch. Place the negative probe on suitable ground on the engine. If it functions properly, there should be no continuity.
  4. Drain out all the engine oil and check the continuity again. There should be no resistance of more than 2 ohms maximum. If it shows a different reading, then you need to replace the switch.

Will a Generator Start With Low Oil?

Generators will still start with low oil but could damage the engine when running for long. Therefore, the newer models have a “low oil shutoff sensor” that will kill the engine automatically when oil levels are too low. This is to prevent the generator from running with no oil, which can cause severe wear and destruction to various parts of the engine.

What Does the Low Oil Sensor Do on a Generator?

The low oil sensor shuts down the engine if the oil level gets too low. This prevents the generator from overworking and damaging the components. Hence, the low oil sensor is a safety mechanism used to detect low oil levels.

Can You Overfill a Generator With Oil?

Overfilling the generator can cause engine problems. If you overfill the engine with oil, then the excess oil will transfer to the air cleaner case and air filter. This will finally cause the engine to choke out and stall. So it is important to know how much oil your generator takes before filling it up.


This article provided you with all the important tips on how to bypass the low oil sensor on the generator. Since these steps are easy to follow, you can solve the issue on your own at home. But always make sure to follow the safety precautions to avoid any possible risks and hazards. If you still have any concerns with the matter, you should contact your technician for advice.