When you put oil in your car, you expect the levels to stay the same until your next oil change, but that’s not always the case. In some cases, oil levels may drop unexpectedly. When this happens, you want to know why your car is leaking and burning oil.
In this article, we explain why your oil levels may drop and whether this is a normal circumstance that occurs with all vehicles. We also tell you what you can do once you notice excessive oil consumption in your vehicle.
The most common reason a car burns a lot of oil is due to worn gaskets or seals. It can also be caused by a clogged crankcase ventilation causing excess pressure inside the engine, which will cause oil to slip through the piston rings and into the combustion chamber.
Here is a more detailed list of the most common causes of a car engine having excessive oil consumption:
6 Excessive oil consumption and combustion reasons
1. Worn gaskets or seals
When the car has damaged or worn crankshaft seals or a valve cover gasket, there may be an oil leak. With this fault, oil is lost every time you drive, requiring you to top up to keep the oil where it should be.
If you notice worn seals or gaskets, you should replace them immediately. In many cases, this can be quite inexpensive, but it helps you avoid costly engine repairs later. Bad seals will cause an external oil leak which should often be fairly easy to locate if there is a puddle of oil under your car after parking it.
2. Clogged crankcase ventilation
When the crankcase ventilation or PCV valve becomes clogged, it can cause excess pressure inside the crankcase which will push oil out of the engine through the seals.
To fix this, locate the crankcase ventilation hoses and PCV valve and make sure air can freely exit the engine. The crankcase vent often has multiple hoses going to the engine, so it’s important to check them all.
RELATED: 7 Symptoms of a Bad PCV Valve
3. Incorrect or low-quality oil
Using the right type of oil is imperative for your engine to run well. Be sure to follow the manufacturer’s recommendations when choosing which oil to use.
Additionally, you want to change the oil regularly. When oil becomes old and dirty, it can no longer lubricate the metal components inside the engine. This excessive friction will cause the engine to consume more oil.
Check the engine oil to see what color it is. It must be tan or dyed yellow. If it is black or dark brown, you have waited too long to get an oil change, if you have a gasoline engine. Diesel engine oil turns black immediately after a change. With an oil filter, drain pan, wrench, and fresh oil, you can change it in twenty minutes.
4. Defective piston rings
When the piston rings are damaged or worn, oil can leak into the internal combustion chamber. Not only will this cause the oil to burn, but carbon deposits can also begin to form on the cylinders and piston rings.
You will notice the oil levels begin to drop. However, the only solution to this problem is to replace the piston rings.
RELATED: 4 Symptoms of a Bad Piston Ring
5. High oil pressure
With high oil pressure, excess fluid passes through the engine. When oil falls into the cylinders, it is likely to burn.
To fix this problem, you must determine the cause of the high oil pressure. The problem may be due to a fault in the central computer or you may have added too much oil during the last service.
6. Old and worn engine
In the first five years of an engine’s life, nothing serious should go wrong. During these first years, the oil should not be consumed in excess and there is no need to worry about it burning.
Once the miles add up, gaskets and seals begin to break down and deteriorate. Small leaks may start and the engine will consume more oil. Additionally, an older engine may have larger tolerances that allow oil to flow through places that do not exist in newer models.
Is burning oil considered normal?
Oil burning is a common topic of discussion among car owners, but manufacturers rarely provide information about the problem. For this reason, what might be considered a normal condition for one engine might be considered excessive for the next.
For example, BMW warns drivers that certain engines burn about a liter of oil less than a thousand kilometers. Additionally, GM claims that typical fuel consumption is less than one liter per 2,000 miles as long as the vehicle is maintained and driven properly.
If your engine uses more than a quart of oil between oil changes, this is definitely something to look into.
How to fix excessive oil consumption
In general, many causes can be avoided by simply maintaining the vehicle and paying attention to any signs of trouble. You also want to make sure you are using the correct type of oil for your vehicle. Check your owner’s manual to make sure you have the correct viscosity.
If you notice any leaks, you want to get them repaired as soon as possible. In many cases, replacing a seal or gasket won’t cost you much and can save you a lot of trouble.
As the engine begins to age, you may want to upgrade to something newer before engine problems arise. When you compare the cost of replacing an engine with the cost of upgrading it, you will see the benefits. It’s best to sell your vehicle while it’s still worth something, especially if you want to use the money as a down payment on something newer.