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Here we’ll look at the causes in more detail, the costs involved, and whether you can attempt the repairs yourself.

The first two causes are common reasons your car loses oil rather than burns oil. These two can be easily discounted and are very cheap fixes.

A car burning oil is due to worn or broken parts. Worn piston rings, corroded valve seals, a broken PCV valve, or a blown head gasket are the leading causes of an engine burning too much oil.  

Oil Filler Cap Is Loose

This seems obvious, but I know people who have forgotten to replace their oil filler cap after topping up the oil level.

They screw the lid back on the 5l container but close the hood without screwing the oil filler cap. Before you check anything else, check this. The cap is probably still there on your engine block. Refill and screw the cap firmly back on. A loose filler cap can lead to air entering the engine and causing poor performance.

The smell of burning oil could be coming from the loose filler cap, and you might even notice smoke from under the hood. 

oil filler cap loose and leaking oil

If your oil has covered the engine – quite possibly – you may need to get the engine steam cleaned. Failing to do this will result in the oil burning outside your engine and could cause damage to other components. It will smoke a lot, too, as your engine warms.

A replacement oil filler cap won’t cost more than a few dollars—a nice cheap fix.

Oil Filter is Badly Fitted or Damaged

The next cheapest fix is an oil filter that’s either been poorly fitted or has become damaged. The oil filter is a cylinder-shaped metal filter often located low down in the engine bay; it may only be visible from underneath.

If you can or want to get underneath your car, you’ll soon be able to see it. If not, look at the owner’s manual for help. You’ll see oil around it if it’s poorly fitted or damaged. You may even see oil on the road or on your drive. 

Once again, you may smell oil burning, but it is a relatively cheap and quick fix if this is the reason. Have a quick check for metal shavings in the oil filter as this can spell big problems.

burning oil and metal shavings in filter

This is a job you could do yourself, but you’ll need an oil filter wrench to remove it as it’s unlikely that your oil filter, however loose, will be able to hand loosened to be removed.

These wrenches are cheap to buy, and you won’t have to drain the oil to remove the filter on most cars. 

Oil filters cost between $10 and $20 depending on the make of your car and the brand of oil filter.

An oil filter wrench costs between $8 and $25, depending on whether you buy a strap or adjustable plier design.

Leaking Valve Cover Gasket

A gasket is made from cork or plastic and creates a tight seal between two metal components.

In this case, to seal the cylinder head and the valve cover. Over time they become brittle, and oil can leak from them. You may not see much oil, but it will leak more if left and not replaced.

The oil should be pretty visible on the engine block. Look around the bolts to see if the gasket has started to fail. 

There is so much pressure inside the engine block that even the smallest gap or hole in the gaskets will allow oil to escape. Even the smallest amount of oil burning can smell a lot worse than the problem is. 

To replace a valve cover gasket costs $50 -$100 for the part and about $70 – $150 for labor. The cost depends on the make of the car and where the valve cover gasket is positioned.

Clogged or Stuck Open PCV Valve 

A PCV valve is not as well-known as a cover gasket or an oil filter, but it serves an equally important part in your engine makeup. 

The PCV stands for positive crankcase ventilation. This valve is situated at the bottom of your engine and is a one-way valve that controls emissions in the exhaust system.

This modern component produces gases when your engine burns fuel. Over time they can fail, and when they do, they allow gas to get in between the crankcase and the pistons in your engine and mix with motor oil. This results in excess oil leaving your exhaust system and may account for the drop in the amount of oil you see on your dipstick when you check. 

https://youtu.be/CzLoEkpdaGs?t=15

Follow one of the hoses leaving your engine, and you will see at the end of it a valve cover. When you’ve located it, remove it and give it a shake. If it needs replacing, you won’t hear anything. This indicates that oil sludge has clogged it up. However, if it produces a rattling sound, the valve is still opening and closing and doing its job. 

Another telltale sign the PCV valve is defective is you may hear whistling noises coming from under the hood, and your engine light may come on.

The good news is that this is a fix that you can attempt to do yourself. A new PCV valve should only cost in the region of $15 and is relatively easy to locate. 

Blown Head Gasket

A blown head gasket happens when the cork seal that keeps the cylinder head and engine block together fails. A blown head gasket causes an overheating engine or poor engine performance.

Unfortunately, we are now getting on to more expensive fixes. Many people have heard the word blown head gasket, which normally fills people with dread. It’s not surprising it can be extremely costly to fix. 

https://youtu.be/QA7KVQq9vKA?t=22

The cost of replacing a head gasket varies enormously depending on the amount of damage done to the head before taking it to a mechanic.  It’s not unusual for the total cost, including labor, to be more than $3,000. 

Worn Engine Valve Seals

Valve seals are made of reinforced rubber, and their purpose is to stop oil from being sucked down into the lower part of the engine. When this happens, the excess oil is burnt off and released through the tailpipe. The smell of burning oil from this is often the first symptom that makes people check their cars’ oil levels.

As mentioned, the seals are rubber and, therefore, relatively inexpensive.

The cost of replacing worn valve seals is between $1,000 and $2,000. Most of the price will be labor as the engine needs to be dismantled to complete the repair.

Worn Piston Rings

The final mechanical reason your car may burn excess engine oil is worn piston rings. Once again, these are located inside the engine, and although the parts needed to replace them are relatively cheap, they will require the engine to be dismantled before the components can be fitted.

The cost of replacing piston rings is $1,000 -$2000, and only $100 of the cost will be spent on replacement rings. The remainder of the total cost will be labor charges.

Does Aggressive Driving Burn More Oil?

Yes. Aggressive driving and burnouts mean that your car engine has to work harder more often. This puts more strain on the seals and gaskets, resulting in oil escaping from the head.

Do Older Cars Burn More Oil?

Yes. As cars age, their valves, seals, and gaskets become less efficient and allow some oil to escape through the exhaust.

If the oil burning is not excessive, check your oil weekly and top up as needed. Some cars will drive perfectly well for 1000’s more miles. Oil is cheap, but a complete engine rebuild will cost thousands of dollars and may cost more than the car is worth.

In Conclusion

Your car is burning oil because of badly worn engine parts. Examples are worn valve seals, and failing piston rings. Both these parts keep oil out of the combustion chamber. When they fail oil gets mixed with fuel and air and burns.

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