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It is normal for generators to consume motor oil as it runs. But needing to add oil every other day because your generator is using a lot more oil than it should is a clear indication of a problem.
So, why is my generator burning oil so fast?
There are many reasons your generator may be using oil so fast, and the most common causes include
- There is too much oil in the engine
- You’re using the wrong grade of oil
- The air filter is either dirty or clogged
- The oil fill cap is loose or damaged
- The unit is running very hot
- The motor oil used is of poor quality
- The generator is old
- The seals and gaskets are worn out
- The piston rings are misaligned
As the engine burns off more oil, it hinders the engine’s normal function. Worse, as the oil level drops, the level of protection inside the engine reduces, which accelerates the rate of wear and tear inside the engine.
In this guide, we’ll take a detailed look at the most common causes of high generator oil consumption and know how to fix them.
Table of Contents
9 Reasons your Generator is Using Too Much Oil
| Cause | Reason | Solution |
| Too much oil in the engine | An increase in oil pressure forces the oil up to the combustion chamber, which burns the oil | Drain the excess oil |
| Wrong grade of oil | Using lower viscosity of oil in the wrong season will make the oil seep up between the piston and cylinder wall and burn the oil | Use an appropriate grade of motor oil depending on the season |
| Air filter dirty or clogged | A clogged air filter creates a vacuum that pulls in the oil from the crankcase into the combustion chamber, increasing oil consumption | Clean the air filter regularly and replace it when needed |
| Oil fill cap is loose | Moving oil inside a running generator can leak out from a loose oil cap and burn as it touches the hot engine | Fasten the oil fill cap or dipstick properly. Replace the dipstick if the gasket or the dipstick is damaged |
| Generator running hot | As the engine runs very hot it breaks down the oil which in turn increases the oil use | Use a generator tent and never run the unit at high load for long periods |
| Poor quality motor oil | Low-quality oil doesn’t break down easily, reducing overall protection and increasing oil consumption | Use high-quality motor oil from the top brand’s |
| Generator is old | Old generators have worn out engines that have larger gaps between the piston and cylinder wall that allows the oil an easy route to the combustion chamber | Replace the engine or better buy a new inverter generator |
| Worn out seals and gaskets | Weak or broken-down seals and gaskets allow motor oil to leak. As the leaked oil comes in contact with the engine, it burns | Replace the worn-out seals and gaskets |
| Misaligned piston rings | Misaligned piston rings provide an easy passage for motor oil from the crankcase to reach the combustion chamber | Take it to an engine repair shop and realign the piston rings |
Why is my Generator Burning Oil? (9 Reasons & Fix)
The reason behind excessive engine oil consumption can be as simple as too much oil in the crankcase to a more complex problem like a worn-out engine. Some causes are easy to fix, whereas others may require professional assistance and money.
However, a generator using too much oil is one problem you shouldn’t ignore. Low oil in a generator’s engine can have serious consequences on a generator’s overall working life.
Here are the 9 most common causes for generator burning oil and what to do about it.
1. Too Much Oil in the Engine
The #1 and the most common reason most camping generators burn oil is that you’ve overfilled the engine oil. When there is too much oil in the generator, the oil pressure inside the engine increases, forcing the oil to find ways to escape.
The increased oil pressure forces the oil out through any weak gasket or up into the combustion chamber, where it burns. Moreover, any oil that is leaking through the gaskets will also burn off as it comes in contact with the hot engine.
The most obvious cause of excessive motor oil in your generator is from the topping of oil with a generator sitting on an uneven surface. In small generators where the fill cap is not easily accessible, you may be forced to tilt the generator to an angle (45 degrees) to pour in oil easily. The uneven surface or the tilt angle can put off the oil level, making you overfill the crankcase.
The easiest way to determine if your engine has too much oil is to open the engine dipstick and check the oil level. Additionally, blue smoke from your generator’s exhaust is another common indication you have excessive oil in your generator.
If your generator shows symptoms of excess oil, you need to correct the problem by draining the excess oil to prevent oil from burning and causing damage to your generator.
Excess motor oil in a generator will not only increase oil consumption but will also cause other mechanical problems. To fix excess oil-related issues, you need to drain the extra oil from your generator’s crankcase.
To drain oil from your generator, locate the drain plug under your generator and drain the appropriate amount of oil in a container. I would suggest draining all the oil and topping it off with a new batch, as draining the right amount can be difficult.
Read More: How Much Oil does a Generator Take?
2. Using the Wrong Oil Grade
Depending on the weather, generators need to run a specific grade of oil to ensure proper functionality. Using the wrong weight of oil can cause a lot of problems including increased oil consumption.
Using a lower weight oil when the outside temperature calls for a higher weight oil means your oil will find its way up to the combustion chamber. As the oil reaches the combustion chamber, it will burn off with the fuel during the combustion process.
Moreover, generators switching from regular motor oil to synthetics may find themselves burning off a lot more oil than usual. Synthetic oil is sleeker than regular oil which makes it easy for the oil to climb up the combustion chamber.
The most obvious sign that you’re using a lower viscosity oil is oil spots under your generator. Using the wrong grade oil will not only burn oil but will also pose other mechanical problems that can create a dent in your wallet.
To prevent the wrong viscosity of oil from burning and causing other problems, you need to drain the old oil and put the right grade oil. As a general rule of thumb, you need a thicker grade oil like 10W30 during summer and a thinner oil like 5W30 during winter to ensure peak performance.
Always refer to your generator’s user manual to find out the recommended type and grade of oil for your specific model.
Read More: Can I Use 5W30 Instead of 10W30 in my Generator?
3. Dirty or Clogged Air Filter
A dirty or clogged air filter is another common cause your generator is burning or consuming more oil than usual. A generator’s engine needs clean air to function, and the air filter is responsible for cleaning the air.
However, over time the air filter collects dirt from the air which may restrict the airflow or prevent it completely. During a combustion cycle, an engine creates a vacuum that pulls in air and fuel in the combustion chamber.
But with the air filter clogged, the vacuum that is created pulls the engine oil lubricating the cylinder walls into the combustion chamber. Once into the combustion chamber, the oil mixes with fuel and burns off which increases your overall oil consumption.
To determine if a clogged air filter is causing your generator to burn oil is look for symptoms like strange engine noise, misfires, reduced fuel efficiency, etc.
To fix this problem, simply clean your generator’s air filter or change it if it is badly broken down.
4. Loose Oil Filler Cap
Though less common, a loose or worn-out oil fill cap or dipstick can be a reason your generator is losing or consuming more oil than it should. As the generator runs, the moving piston and crankshaft move the oil vigorously.
With a loose or worn-out oil fill cap, the oil leaks out of the engine and burns as it touches the hot engine. Visually inspect the dipstick to check if a faulty dipstick is a reason your generator is burning more oil.
You need to replace the dipstick with a new one if the gasket on the dipstick or the dipstick itself looks broken down. Moreover, fasten your dipstick properly after checking the oil level or changing the oil to prevent oil from leaking out through it.
5. Your Generator is Overheating
An overheating generator can pose a lot of problems to the unit itself while also increasing oil consumption. From outside temperature to a high electrical load, there are many reasons why your generator might be overheating.
An increase in the engine temperature increases the oil temperature inside the generator. A rise in oil temperature accelerates the breakdown of the engine oil, which in turn helps burn more oil.
To prevent your generator from overheating and burning the oil, make sure not to run the unit at its maximum load. Moreover, use a generator tent, like the GenTent when using your generator under the hot summer sun.
6. Poor Quality Oil
With time and use, the motor oil inside a generator breaks down and loses its quality, increasing the oil consumption. As the oil degrades, it loses its ability to adequately lubricate the internal moving parts of the engine, increasing friction and heat.
The added heat that is produced inside the engine accelerates the oil consumption rate while increasing wear and tear. There are a few things you can do to prevent excessive oil consumption caused by oil quality.
Firstly, make sure you check the condition of your generator oil regularly. A good rule of thumb is to check it every morning before you start using your generator. Remove the dipstick of your generator to check the level and color of the oil.
If the color of your motor oil is dark brown or black, you need to change the oil as soon as possible. Changing a portable generator oil is as simple as unscrewing the drain plug, and the oil will drain out.
Secondly, make sure to use a higher quality motor oil from top brands. Going with less popular brands just to save a few bucks may lead to increased oil consumption or worse, expensive repairs.
7. The Engine is Old
A combustion engine wears down with age creating many problems, including increased oil consumption. As a generator’s engine ages, the gap between the piston and cylinder walls increases, making it easy for the oil from the crankcase to reach the combustion chamber.
As the oil reaches the combustion chamber, it mixes with the fuel and burns. As such you may notice a high oil consumption on a unit that has a few 100 hours of runtime under its belt compared to newer generators.
To prevent a generator from consuming excessive oil as the unit ages are far from straightforward. You either need to replace the aged engine or bore out the cylinder wall and replace it with an appropriate size piston.
To me, both the fixes sound troublesome and most importantly, expensive. Instead, I would suggest you buy a new inverter generator as changing the engine will cost about the same as a new unit.
8. Worn Out Seal & Gasket
One of the first things that wear out easily as the generator ages are its seals and gaskets. As the seals and gaskets around the engine break down, it increases the possibility of engine oil leaks.
When the engine oil leaks from in or around the generator’s engine, the leaked oil burns as it comes in contact with the hot engine. Over time, these damaged seals leak more, increasing the oil-burning ratio.
The most obvious signs of oil leaks caused by worn-out gaskets are oil stains on the engine and ground. Moreover, as the oil burns when it comes in contact with the hot engine, it produces grey or white smoke from the engine.
To correct this problem you need to take your generator to a service center and replace the worn-out gaskets.
9. Misaligned Piston Rings
A generator’s pistons are fitted with multiple metal rings that are not a complete circle but have a small gap. The gaps are mainly there to allow the rings to contract and expand depending on the temperature.
Over time, the gap on the rings may align right on top of each other, allowing the oil from the crankcase to reach the combustion chamber. As the oil reaches the combustion chamber, it burns, increasing oil consumption.
To correct this problem, you need to remove the piston and install the rings in a way that gaps are not in line with each other. This will restrict the oil from reaching the combustion chamber and limit the oil from burning.
What are the Common Signs of Generator Burning Oil?
By now you are well aware of the most common cause why your generator is burning oil. Though these are not the only reasons your generator is consuming more oil, but are the most common in portable generators.
However, there are signs and symptoms you can look for to determine if your generator is using excessive motor oil.
Some of the most common signs include
- Blue smoke from the exhaust
- Grey or black smoke from the engine
- Oil stains on the engine and ground
- Frequent low oil shutdown
- Your generator performs poorly
- Increased fuel consumption
A generator burning excessive oil is a sign of a bigger problem that is waiting to unfold if not addressed on time. Make sure to check for these symptoms and run scheduled maintenance on your generator to extend its working life.
Frequently Asked Questions
How Fast do Generators Burn Oil?
Though it is normal for a generator to burn some oil while in operation, the rate of oil burns depends on the brand and type of generator. Moreover, your generator may burn more oil than it should because of the causes we spoke about above.
What Happens if A Generator Runs Out of Oil?
The primary function of motor oil is to lubricate the internal parts of the engine and keep it protected. However, a drop in oil level inside the engine decreases the level of engine protection.
As a result, running a generator with low oil or below the recommended level can cause serious damage to the engine’s internal parts. Running a generator for a considerable amount of time with a low oil level can damage the engine beyond repair.
Most modern portable generators come with a low oil shutdown down feature that prevents the unit from running if low oil is detected. However, you need to manually check the oil level regularly if your unit doesn’t come with this feature.
Conclusion
A generator burning oil during operation is normal, but an excessive amount of oil consumption is an indication of a bigger problem. As the oil level drops, the level of protection inside the engine falls.
This increases the wear and tear on the engine’s internal parts, shortening the engine’s life. Your generator may burn oil for a wide variety of reasons but the ones we spoke about above are the most common.
Make sure to address the problem immediately once you identify why your generator is burning oil.
FAQs
What is an easy fix for burning oil? ›
- Check for leaks regularly. ...
- Use the correct oil grade. ...
- Follow the recommended oil change interval. ...
- Avoid excessive idling. ...
- Drive responsibly.
Getting your piston rings replaced is the only good solution. When there is high oil pressure, oil will flood through the engine in excessive amounts. This oil will likely fall on the cylinders and get burnt up. This high oil pressure could be due to a faulty setting on the vehicle's central computer.
What is the most common cause of excessive oil consumption? ›Under normal operating conditions, excess oil consumption is generally a mechanical problem. In the majority of cases where oil consumption problems have been investigated, it usually turns out to be a leak issue – either the valve cover gasket is leaking, crankshaft seals leaking, or one of the main seals is leaking.
How much oil does a generator burn per hour? ›Generators & Oil Consumption. All generators consume some oil during operation. Our experience with Generac generators indicates that you can expect the generator to consume between 1/2 and 3/4 of a quart of oil when operating over a continuous 24 hour period.
Will thicker oil stop oil burning? ›To slow oil consumption, a higher viscosity grade oil can be used, especially an oil with a higher operating temperature viscosity. Oil burns when at its hottest and therefore thinnest viscosity.
Can burning oil be fixed? ›fixing oil burning outside the engine
your oil filler cap or oil filter may be the source. replacing these items will usually solve the problem. make sure that the oil filter is properly screwed on and tight enough. another common source is the valve cover area.
Superior temperature resistance. Synthetics can safely handle higher operating temperatures without oxidizing (burning) or breaking down. The upper limit for most mineral-based oils is about 250 to 300 degrees F. Synthetics can take up to 450 degrees F. or higher (some as much as 700 degrees F).
Why is my oil disappearing but no leak? ›If your engine is low on oil but there isn't a leak, that means it's probably being burned inside the engine. A bad PCV valve is a frequent culprit in the case of burning oil--but what is it, exactly? A PCV valve is designed to let air escape when the pressure in the crankcase is too high.
How do you diagnose burning oil? ›Blue smoke from the exhaust: Bluish smoke can indicate your car is burning oil during the combustion cycle. Burning oil smell: A thick burning oil smell could mean oil is seeping onto hot engine parts. Frequent low oil light warnings: Regular low oil warnings can indicate excessive oil consumption or a car burning oil.
Can you just keep adding oil if you have an oil leak? ›If it's a little on the low side, top up the oil and check again the next day to see if the level has dropped significantly. Avoid adding oil and ignoring the fact that the level keeps dropping - oil leaks can be potential fire hazards so it's important to ensure that everything is working as it should.
Will Sea Foam help with burning oil? ›
If oil burning is the culprit and it's caused by deposits/varnish, Sea Foam will help overcome it. Adding Sea Foam Motor Treatment or High Mileage (what I would use) during every oil interval will progressively help to reliquefy the heavier oil residue that's plugging up your Toyota's oil flow.
Can bad spark plugs burn oil? ›Without a reliable spark from your spark plugs, your engine has to account for the underperformance. It does so by increasing fuel in your cylinders to maintain the pressure in your combustion chamber. As a result, your fuel economy worsens, and oil consumption increases.
What is best oil additive for older engines? ›- Lucas High Mileage Oil Stabilizer. ...
- Valvoline High Mileage with MaxLife Technology Synthetic Blend Motor Oil. ...
- Pennzoil High Mileage Motor Oil. ...
- Slick 50 Recharged High Mileage Treatment. ...
- Gumout Fuel System Cleaner. ...
- Royal Purple High Mileage Synthetic. ...
- Techron Fuel Cleaner. ...
- Mobil Super High Mileage Oil. $80 at Amazon.
The hotter the motor, the thinner the lubricant will be. It would be easier for a thin oil to reach the engine, so using a lubricant that is considered too low in viscosity will mean more oil consumption than usual.
How many hours should a generator run in a day? ›Manufacturers typically recommend that your generator run continuously for no more than 500 hours maximum. A portable generator, however, should only run continuously for shorter periods of time – between six to 18 hours, depending on the model.
How long should oil last in a generator? ›Experts recommend doing a full oil change every 50 to 200 hours of operation. If your generator has been running every day or over an extended period of time, change the oil more often — as in every 50-100 hours.
How many hours are normal on a generator? ›On average, a standby generator can run for up to 3,000 hours powering a medium-sized home, though it is recommended you do not run a generator for longer than 500 hours continuously.
Which is thicker 5W-30 or 10w30? ›5W-30 multi grade oil is ideal for private vehicles and light-duty petrol and diesel engines. It also provides a better cold temperature start than 10W-30 oil. On the other hand, the slightly thicker oil,10W-30, provides better lubrication for commercial vehicles and heavy-load engine cars.
Can I put 10w30 instead of 5W-30? ›You can use 10w30 instead of 5w30 oil since both meet the SAE standard for viscosity at operating temperatures. Generally, the viscosity difference between the two is neglectable. However, it's important to note that a 10w30 oil will move slower than a 5w30 oil in cold environments.
Is thicker oil better for older engines? ›A: Yes. This is a practical method to improve oil pressure in an older, high-mileage engine. The slightly thicker oil film from the heavier base weight oil - 10W - can help protect worn engine bearings as well.
How much does it cost to stop engine from burning oil? ›
The minimum repair will be changing piston seal rings, also known as oil control rings, but it could even require a complete engine replacement. You can expect it to cost anywhere from $1,000 to $5,700 for a gas engine. A diesel engine is much higher still.
How long will an engine burning oil last? ›It is a fact that most engines will burn some oil. The majority of manufacturers consider one quart of oil in the range of 1,500 miles to be acceptable. It should also be pointed out there are some performance vehicles that will consume a quart of oil in less than 1,000 miles and is also considered acceptable.
Can water put out burning oil? ›You should never put water on a grease fire, according to the National Fire Protection Association (NFPA).
Which motor oil is best? ›| Engine oil name | |
|---|---|
| Best engine oil overall | Mobil 1 Extended Performance |
| Best engine oil overall runner-up | Castrol GTX Magnatec |
| Best synthetic engine oil | Pennzoil Ultra Platinum Full Synthetic |
| Best synthetic engine oil runner-up | Amsoil Signature Series Synthetic |
This is because synthetic oil has additives that make it more slippery than regular oil, which could lead to leaks in older vehicles.
Does high mileage oil help with burning oil? ›Reduced oil consumption: High mileage vehicles tend to leak and burn off more oil than younger cars due to degraded engine seals. High mileage oil rejuvenates degraded seals, which leads to less oil consumption and burnoff.
Does white smoke mean burning oil? ›White smoke from the exhaust can spell big problems with your engine, and the smoke's white color tells us that it's water vapor (blue = burning oil, gray or black = fuel). Specifically, coolant is escaping from the cooling system into the combustion chamber.
How can oil leaks be stopped? ›One of the easiest ways to fix the leak yourself is to use a stop leak additive or high mileage oil blend. Such products can soften and condition your car's rubber seals to stop and prevent further automotive leaks. It may take up to a few hundred miles of driving before the leak is completely sealed.
Why is my engine burning oil but no smoke? ›There could be two possible reasons as to why your vehicle is burning oil. (1) It may have an oil leak or (2) it could be burning oil during the ignition cycle. One common problem is if the cylinder walls are allowing oil to leak up from the bottom of the engine, past the piston and into the combustion chamber.
Can you have an oil leak without seeing it on the ground? ›When a car mysteriously loses oil, there are usually two possible causes: either you've sprung a leak, or your engine is burning it away. Though you may not see any visible signs of leakage, less noticeable parts like a worn seal or leaky rings may be the culprit.
Do oil leaks need to be fixed? ›
Leaks left unchecked can get on rubber hoses or seals and cause them to degrade prematurely. Leaking oil can cause ugly stains on your driveway and are an environmental hazard.
How do I know if I have a lot of oil leaks? ›- Dark puddles under your car. When you back out from your driveway or parking space, check to see if there are dark brown or yellow puddles where your car was sitting. ...
- Smoke from the engine. ...
- The dashboard oil light. ...
- Engine overheating. ...
- Smell of burning oil.
Immediately immerse the burn in cool tap water or apply cold, wet compresses. Do this for about 10 minutes or until the pain subsides. Apply petroleum jelly two to three times daily. Do not apply ointments, toothpaste or butter to the burn, as these may cause an infection.
How long does it take for Sea Foam to work in oil? ›Allow five to fifteen minutes for the Sea Foam to soak into the deposit buildup. After the soak period, restart the engine and be prepared to drive/operate for 30 miles. Don't be afraid to run it hard when possible and safe – An engine under load produces the necessary heat and compression for optimal cleaning.
What are the symptoms of oil fouled spark plugs? ›Oil fouling of a spark plug typically results in a shiny, black appearance. If enough oil is in the combustion chamber, the deposits can build up on the tip, porcelain or shell. If you can't determine if it is carbon or oil fouling, smell the plug; it will smell like engine oil.
What are the symptoms of oil on spark plugs? ›- Blue smoke form exhaust.
- Reduced fuel economy.
- Reduced engine performance.
- Possible engine misfires.
- Engine backfires.
Lucas High Mileage Oil Stabilizer helps to control blow-by, dry starts and oil burning - maximizing efficiency, reducing harmful emissions and extending oil life. Lucas High Mileage Oil Stabilizer can also be used as an IDEAL ASSEMBLY LUBE.
What is the best motor oil to prevent sludge? ›Mobil 1 advanced full synthetic motor oils contain fewer impurities than conventional oils. That means they're designed to better resist the formation of sludge, maintain their viscosity and ability to flow, and prevent deposits from forming.
What additive in oil keeps engines clean? ›Dispersants. Dispersants are mainly found in engine oil with detergents to help keep engines clean and free of deposits. The main function of dispersants is to keep particles of diesel engine soot finely dispersed or suspended in the oil (less than 1 micron in size).
What causes engine to consume oil? ›Oil consumption: 5 common causes
Seals and gasket, the bearings, cylinders, ring grooves, connecting rods can be worn or damaged. Cylinders that were not honed properly when the engine was built (or rebuilt), incorrect installation of the piston ring, or other improperly installed parts.
What causes a generator to burn out? ›
Overheating can be caused by a number of things, such as the generator being overloaded, a winding insulation breakdown due to a fault, or insufficient bearing oil lubrication. Overheating a generator decreases its operational life, and can outright destroy the generator if the problem isn't solved quickly enough.
Does synthetic oil last longer in a generator? ›Synthetics resist high temperature breakdown much better than conventional oils which results in increased hydrodynamic bearing film thickness (longer bearing life) and reduced oil consumption. Since a small air-cooled engine runs extremely hot, compared to a liquid cooled engine, this is important.
What oil is best for generators? ›Above 32°F, use SAE 30. Below 40°F and down to -10°F, use 10W-30. Synthetic 5W-30 can be used in all temperatures. Oil should be changed after the first 20-30 hours of operation and every 100 hours of run time thereafter.
Can you add oil to a generator while it is running? ›Never add fuel while unit is running or hot. Allow generator and engine to cool entirely before adding fuel. Never store a generator with fuel in the tank where gasoline vapors might reach an open flame, spark or pilot light. Do not smoke near fuel or generator.
Is there an additive to stop oil burning? ›Lucas High Mileage Oil Stabilizer helps to control blow-by, dry starts and oil burning - maximizing efficiency, reducing harmful emissions and extending oil life. Lucas High Mileage Oil Stabilizer can also be used as an IDEAL ASSEMBLY LUBE.
Will thicker oil stop burning? ›A lot of oil-burning takes place because an engine's piston rings are worn out, and thicker oil won't fix that. Using thicker oil is also a particularly bad solution for modern cars.
What are the common generator faults? ›- Leaks. The first generator problem that can arise are leaks. ...
- Low Coolant. The second problem that can cause generator problems are the generator being low on coolant. ...
- No Fuel. ...
- Generator Failure. ...
- Fuel Leaking Into the Tank. ...
- Dead Battery. ...
- Control Malfunction. ...
- Block Heater Wear.
Running your standby generator longer than the recommended use period can damage the generator and your home's appliances and electrical system. Make sure to track how long your generator runs to avoid overworking it.
How do I know if I'm overloading my generator? ›- A drop in power output. When you notice a reduction of power output in your generator – it's a clear sign of a generator overload. ...
- Starts to overheat. Hear any loud noises? ...
- Soot becoming apparent in the exhaust.