Does it smell like burnt oil in the car? For this reason

An annoying problem that motorists can encounter is the smell of burnt oil that they smell in the car.

 Aside from not being able to drive the car with this smell, this symptom can indicate certain problems.

Does it smell like burnt oil in the car? For this reason
Does it smell like burnt oil in the car? For this reason

Does it smell like burnt oil in the car? For this reason

The smell of burnt oil in the car can indicate engine and transmission problems. The most common causes are leaking valve cover gaskets, cylinder head gaskets, shaft seals, and air system problems such as a clogged air filter.


  1. Where does the smell of burnt oil come from?
  2. From the engine compartment, there is a smell of burnt oil
  3. The smell of oil comes from under the car.
  4. Other causes
  5. Conclusion

Where does the smell of burnt oil come from?

The smell of oil generally enters the passenger compartment through:

  • The air ducts of the ventilation system, located above the engine compartment. 
  • The warmer the engine gets, the more noticeable it becomes.
  • The cabin fan when you turn it on and the recirculation mode is off.
  • Door seals; pedal assembly.

The persistent smell of burnt oil inside the vehicle is a clear indication of a technical problem with the engine or, in lesser cases, problems with the gearbox and accessories. These sources can be located in the engine compartment, and this bad odor is especially noticeable when the engine is hot.

If you can't smell the odor coming from the engine compartment, it's worth looking under the car, as the odor can spread through the exhaust system. It could come from the gearbox or other parts under the car.

As the oil piles up on the heated walls of the cylinders, exhaust system, and/or associated components, the consequence is a foul odor of burnt oil. Most of the time, this is due to an issue with the engine.

Oil leaks often create a stronger smell as the engine gets hot, and the oil starts to burn. The symptoms appear almost immediately after starting the engine when oil enters the exhaust system. In the rain or snow, the ingress of oily moisture or reactive particles from the road surface into the exhaust pipe may be the cause of the transient odor.

You can determine the exact location based on certain symptoms. If you notice the odor while driving with the windows open and the odor occurs with the interior ventilation activated or increases and disappears after a short time with the air recirculation mode activated, the odor is most likely coming from the interior engine.

If you smell the smell with the windows open, and it goes away after all the windows are closed, then the smell is coming from under the car. If the oil is expelled directly through the exhaust system, in addition to the smell, blue smoke may be seen coming out of the tailpipe.

From the engine compartment, there is a smell of burnt oil

There are several methods to check exactly where the smell is coming from. If you suspect the smell is coming from the engine compartment, you can determine this by visual inspection by finding traces of oil in the engine.

At best, oil marks may be present due to recent servicing. When changing the oil, traces of oil accidentally got into the engine and were not cleaned off. Also, available for gearbox oil.

Other causes include a leaky valve cover, leaky crankshaft, and camshaft seals, or a clogged or faulty crankcase ventilation system, usually a hose, and a broken head gasket. These issues can be difficult to fix, so it's best to go to a repair shop for proper investigation.

For example, if there is an oil leak under the valve cover gasket, the mechanic can try to tighten the fasteners on the cover. If this does not solve the problem, the gasket should be replaced.

If oil is leaking from the crankshaft or camshaft seals, it may indicate increased pressure in the cylinder block caused by a clogged crankcase ventilation system or worn oil seals.

The seals should be changed when the oil level is normal, the air circuit is not clogged and there is no sign of overpressure (no smoke when opening the oil filler cap). 'Oil.

If the oil leaks are due to a bad cylinder head gasket, things get a little complicated here, and you have to go to an authorized workshop.

Speaking of problems with a head gasket, not only oil but also coolant, including the mixture of the two in the cooling system and the cylinder block, can leak.

The smell of coolant and white smoke from the exhaust, the presence of oil stains in the antifreeze, and a change in the level of the expansion tank indicate a malfunction. A broken gasket should be replaced as soon as possible.

The smell of oil is coming from under the car

As in the case presented above, traces of oil indicate a problem, but to find them you need a shaft or an elevator, see below. These oil leaks most often come from the oil seal on the transmission input shaft or the oil seal on the crankshaft. The exact cause cannot be determined until the transmission is removed.

Additionally, the oil pan may leak due to a worn gasket, insufficient tightening of the drain plug, or deformation of the O-ring. Worn parts should be replaced to eliminate the cause.

To more accurately determine the problem and distinguish between the types of oil involved, it can be said that gear oil is darker, smells of sulfur, and has a thinner oil film than engine oil.

Other causes

If you found no traces of oil in the engine compartment and under the car, check the exhaust. A strong odor, oil stains, and blue smoke may indicate a serious problem.

The cause may be worn piston rings, worn valve stem seals, or problems with the turbo on supercharged vehicles. A full engine diagnosis is necessary to eliminate the cause.


Oil stains can not only indicate a problem with seals, engine, and transmission, but driving with this bad smell can be very uncomfortable.

Some solutions target simple repairs like replacing gaskets, but diagnosing and repairing oil leaks can become very tricky and difficult, even for a professional. For this reason, it is best to go to an authorized repair shop when looking to repair oil leaks for the best results.

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