5 Causes of Excessive Oil Consumption (and How to Fix)

(Updated on May 29, 2020)

We all know the main purpose of oil is to lubricate the components of an engine, so they can keep running smoothly. There is a certain level of oil consumption in which an engine will have under normal conditions.

For modern engines, they should consume less than 1/2 quart of oil every 5,000 miles of driving. Most newer cars consume much less. This is not a lot of oil and most car engines will get along just fine with this much.

But there are still things that can happen to change this oil consumption by making the engine demand more oil. If you don’t supply the engine with enough oil or at least fix the problem that is causing it lose more oil, then you could end up damaging your engine. That is the last thing that you’ll want to happen.

Top 5 Reasons Your Engine is Using Too Much Oil

Below are the five most common causes of excessive engine oil consumption.

1) Worn Seals or Gaskets

valve cover gasket leak

If your vehicle has worn out or damaged crankshaft seals or valve cover gasket, then it will likely be leaking oil. Once that happens, your engine will be losing oil whenever you’re driving. This means you will need to constantly top off the engine oil to avoid engine damage.

If you have seals or gaskets that are leaking oil, get them fixed asap. Usually it’s a fairly inexpensive process that will save you a lot of money in the long run.

2) Bad Quality Oil

low oil symptoms

If you use the wrong type of oil in your engine, or your oil is simply old and has accumulated a lot of debris and dirt, then it will start to burn.

More importantly, the oil won’t be able to adequately lubricate the components of the engine because of its condition. This will force the engine to consume more oil.

If your engine oil is dark brown or black in color, get your engine oil changed as soon as possible. It’s an easy DIY job. All you need is new oil, oil filter, oil drain pan, car ramps, wrench, and about 20 minutes.

3) Worn Piston Rings

damaged piston

If you have worn out or damaged piston rings, oil will be able to seep through them and then enter the internal combustion chamber. This will cause the oil to burn while carbon deposits form on the piston rings and cylinders.

Worst of all, your oil level will continue to decrease making it necessary to constantly top off oil. Getting your piston rings replaced is the only good solution.

4) High Oil Pressure

high oil pressure

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. A similar problem is adding too much oil during an oil change.

5) Old Engine

old dirty car engine

The first five years of your engine’s life will be the best years. These are the years when the engine will need the least amount of oil because its components are still new and strong. But after you’ve put enough miles on your engine, the various seals and gaskets will start to deteriorate and cause small leaks.

This means the engine will simply consume oil quicker. In addition, older cars have bigger tolerances where components connect which can allow oil to get through spots which wouldn’t exist in modern vehicles.

6) Synthetic Oil

synthetic motor oil

In most cases, synthetic oil lubricates engines better than conventional oils. But since synthetic oils are formulated differently, they have different flow properties. This means that synthetic oil is sometimes able to get through tighter openings than regular oil.

If you have an older engine or your seals and gaskets are starting to deteriorate, synthetic oil can often be the culprit when it comes to high oil consumption and you’re left with a low level of oil. Switching to a conventional oil will often stop any minor leaks.

Read also: 5 Causes of Car High Fuel Consumption in Gasoline and Diesel Engines

How to Fix Excessive Oil Consumption

Most of these causes are fixable and preventable if you simply pay attention to the oil that you’re using and all the components that work with it.

If you have an old engine, then you should seriously consider just selling your vehicle for a newer one that has a new engine in it. There is no sense in spending thousands of dollars just to replace the engine of an old vehicle, since there are so many other components that could still go wrong too.

As for the rest of the causes, just remember to use top quality oil that is recommended by your vehicle’s manufacturer. Fix any oil leaks as soon as you notice them and replace your piston rings and valve stem seals when necessary.

If you follow this advice, you should be in good shape with your engine’s oil consumption.

22 thoughts on “5 Causes of Excessive Oil Consumption (and How to Fix)”

    • My wife has a 2007 Toyota Rav4 with a 2.4 liter engine. It was very common for these to begin burning oil with age. I was told by a Toyota rep that it was caused from a piston and piston ring design flaw. They redesigned the pistons and rings to correct this. Apparently on the new pistons where the holes are locate on the oil control rings they added more drainage holes and made them larger to allow more oil to flow past which was said to prevent gumming and sticking of the rings. Once the rings gets stuck on the ring lands this would allow oil to get past and then get burned in the combustion chamber. Fortunately for us we had an oil consumption test done at the dealership. It failed the test which allowed us to get the top-end rebuild, this consisted of new piston rings gaskets fluids Etc. This work was done under warranty.

      Reply
  1. Does over-heating cause oil shortage in engine? I am asking because i experienced a couple of overhearing last year, after fixing the problem i started noticing shortage of oil

    Reply
    • It’s possible. For instance if your car overheated because of a head gasket leak, the oil and coolant would mix. Some of both might burn off in the combustion chamber.

      Reply
      • But there is no oil sign in my coolant. Just a little smoke when starting for few seconds and the oil keeps going down

      • Perhaps you are just burning oil and the root cause of the overheating is unrelated. A leak down test should give you a pretty good idea of what’s going on either way.

    • Definitely, since any leak can range from minor to severe. You’d likely see a puddle or steady drip of oil coming from the front of your engine if the level was dropping quickly. To avoid catastrophic engine damage from loss of oil, have your vehicle checked out by a mechanic.

      Reply
    • You probably have an oil leak somewhere. First check the drain plug, as this is a common cause of a leak. If the drain plug is leaking, use a crush washer when you change the oil. If the leak continues from this location, you may need to replace the drain plug or oil pan.

      You could also have leaks in other places. You’ll first need to identify the leaks before you can correct the problem.

      Reply
  2. Questions
    My car Verna Hyundai 2011 transform model overhauled with replacement of piston, valves, etc but it is consuming oil when AC is put on.approx.1ltr oil in 400 km. The local mechanic tried all possibilities but could not rectify them. Please answer if possible?

    Reply
  3. Hello, my diesel Hilux Surf car has constant engine oil shortage and is emitting alot of black smoke. What could be the cause please?

    Reply
  4. Yeah, high engine temperature is also the cause. When the engine temperature increases, oil temperature too increases thus consumption increase. Though, this doesn’t consume too much oil compared to the other causes.
    NB: Just check on the engine coolant, and fix any problem that might be on your car cooling system (also, ensure that the fan movement is OK).

    Reply
  5. Sadly all new engines now use very low strength piston rings to cut down on friction between the cylinder walls and rings all to improve gas mileage and make it “greener”
    They also use the thin as water 0W-20 oils for the same reason.
    As a result the weak oil retainer rings fail to keep the thin oil from being sucked or blown past these weak rings resulting in oil burning engines not seen since the 1950s.

    Ironically these “green” engineering measures have actually caused MORE pollution and early engine failures than has been seen for many decades.

    As a result, all new cars are now simply designed to FAIL instead of being designed to LAST.

    They are now throw away vehicles that cost 4 times as much as the ones that used to last twice as long and burned ZERO oil.

    Thin oil, weak piston rings, and GDI are the perfect storm the greenies wanted to finally destroy the internal combustion engine once and for all.

    Reply
    • Yeah, emissions and efficiency have definitely been a critical focus in most vehicles since the oil crisis in the 70s. There have been several advancements in engineering that allow modern vehicles to run 0W-20 oil, including tighter tolerances, smaller oil journals, and high quality synthetic formulas. Running a 0W-20 oil will do no harm to an engine that was designed to use it.

      I would argue that many premature engine failures are not due to the “green” engineering measures, but trying to rush an engine design out the door before it’s thoroughly tested and ready to go. For instance, early cylinder deactivation systems on some vehicles caused piston ring issues or excessive oil consumption like you described here.

      You’re right that vehicles cost a lot more now than they used to, but they’re not really four times more expensive. Inflation has driven the cost of vehicles up drastically in the last 50 years, so it’s apples to oranges comparing the MSRP of a new vehicle and an old one without adjusting for inflation. For instance, a 1971 Corvette coupe had an MSRP of $5,496.00. Adjusted for inflation in 2021 that would be $36,877.61 according to the Bureau of Labor Statistics (https://www.bls.gov/data/inflation_calculator.htm). A brand new C8 Corvette starts at $59,900, which is less than double the adjusted price. On top of that, the C8 is basically a supercar, offering vastly superior performance and safety compared to cars released 50 years ago.

      Reply
  6. I am experiencing oil shortage and too much fuel consumption with My Toyotal Camry 2007, 2.4 Engine. I have checked for oil leakage but no sign of leakage. Please what do I do to resolve it. As my local mechanic has tried all he could but all to no avail

    Reply
  7. Refer cause no 4. This high oil pressure could be due to a faulty setting on the vehicle’s central computer.
    Is it possible to rectify this? please assist!

    Reply

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