What causes burning oil smell?

Leaking valve cover gasket; Oil spilled during a recent oil change; Leaking oil pan gasket or drain plug; Oil leaking onto the turbocharger; Failing front or rear main seal / camshaft seals; Clogged PCV valve raising crankcase pressure.

Caution

Burning Oil Smell: Where It's Coming From and How Serious It Is

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That hot, acrid burning-oil smell almost always means engine oil is escaping a leak and dripping onto a hot surface like the exhaust manifold, turbo, or engine block, where it burns off. The most common source is a leaking valve cover gasket, but it can also come from an overfilled or spilled oil change, a bad oil pan gasket, or oil burning inside the engine. You may also notice faint smoke from under the hood or a low oil level.

Common causes

1
Leaking valve cover gasket
The most common cause. The valve cover sits high and near the hot exhaust manifold, so oil weeping from a failed gasket burns off and produces a strong smell, sometimes with visible smoke.
2
Oil spilled during a recent oil change
Oil dripped on the engine or exhaust during service burns off over the next few drives. If the smell started right after an oil change and fades, this is usually it.
3
Leaking oil pan gasket or drain plug
A seeping pan gasket, loose drain plug, or bad filter seal drips oil onto exhaust components below, creating a burning smell and spots on your driveway.
4
Oil leaking onto the turbocharger
On turbo engines, oil from a leak or a failing turbo seal hits the extremely hot turbo housing and burns instantly, producing a sharp odor and sometimes smoke.
5
Failing front or rear main seal / camshaft seals
Crankshaft and cam seals harden with age and leak oil onto the engine and exhaust. These leaks tend to worsen gradually and are a bigger job to fix.
6
Clogged PCV valve raising crankcase pressure
A blocked PCV system builds pressure that forces oil out past gaskets and seals, accelerating leaks that then burn on hot parts.

What to do

A burning oil smell is worth acting on promptly because oil pooling on a hot exhaust is a fire risk, and a serious leak can run the engine low on oil. Check your oil level on the dipstick and look under the hood for oil on or around the valve cover and exhaust; top up if it's low and watch for smoke. If the smell is strong, persistent, or you see smoke, get it inspected soon to find and seal the leak.

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Common causes

Leaking valve cover gasket

The most common cause. The valve cover sits high and near the hot exhaust manifold, so oil weeping from a failed gasket burns off and produces a strong smell, sometimes with visible smoke.

Oil spilled during a recent oil change

Oil dripped on the engine or exhaust during service burns off over the next few drives. If the smell started right after an oil change and fades, this is usually it.

Leaking oil pan gasket or drain plug

A seeping pan gasket, loose drain plug, or bad filter seal drips oil onto exhaust components below, creating a burning smell and spots on your driveway.

Oil leaking onto the turbocharger

On turbo engines, oil from a leak or a failing turbo seal hits the extremely hot turbo housing and burns instantly, producing a sharp odor and sometimes smoke.

Failing front or rear main seal / camshaft seals

Crankshaft and cam seals harden with age and leak oil onto the engine and exhaust. These leaks tend to worsen gradually and are a bigger job to fix.

Clogged PCV valve raising crankcase pressure

A blocked PCV system builds pressure that forces oil out past gaskets and seals, accelerating leaks that then burn on hot parts.

What to do