# Why is my car leaking oil? **Verdict:** Drive to a shop this week - **Most common cause:** Leaking valve cover gasket - **Urgency:** This week - **Typical fix:** $150-$1,800 - **Causes to check:** 5 ## Quick answer Most engine oil leaks come from a hardened valve cover gasket, a loose drain plug or oil filter, or a leaking oil pan gasket. Crankshaft seals and the oil filter housing or oil pressure sensor are less common sources. A small seep is not urgent, but check the oil level often, and stop driving if the oil pressure light comes on or oil drips onto the hot exhaust. ## What is happening? Engine oil lives in a sealed system. It is pumped from the pan up through the filter, into the engine's bearings, camshafts and valves, and then drains back down. Gaskets and seals between the metal parts keep it inside. Rubber hardens and shrinks with years of heat, and once a seal loses its grip, oil seeps out, collects dirt and eventually drips. Most leaks start slowly and get worse as the gasket ages further. It matters for three reasons. If enough oil is lost, the bearings and other moving parts lose lubrication and can be destroyed within minutes. Oil dripping on a hot exhaust manifold smokes and, in the worst case, can start a fire. And oil on rubber parts such as engine mounts, hoses and the serpentine belt softens them so they fail early. A small leak caught early is usually a gasket job, not an engine. ## What causes it? The 5 most likely reasons 1. **Leaking valve cover gasket** (most common), $200-$800. The valve cover sits on top of the engine, sealed by a rubber gasket that hardens and shrinks after years of heat. Oil then seeps down the sides of the engine and can drip onto the exhaust manifold, causing a burning oil smell and light smoke from the hood. It is very common on engines past about 100,000 miles. How to confirm: The top edges of the engine are wet and dark with oil and dirt, oil is running down from the joint between the valve cover and cylinder head, and you may smell burning oil after a drive. Fix: Replace the valve cover gasket. 2. **Loose drain plug or oil filter** (common). After an oil change, a drain plug that was not tightened, a reused or missing crush washer, or a filter with a doubled or pinched gasket can leak. These leaks usually start within days of the service and drip from the lowest point of the engine. A badly installed filter can leak fast enough to empty the engine. How to confirm: The leak started soon after an oil change, and the drips come from the drain plug at the bottom of the oil pan or from around the oil filter, which may look wet all over. Fix: Tighten the plug with a new washer or refit the filter. 3. **Leaking oil pan gasket** (common), $250-$900. The oil pan bolts to the bottom of the engine with a gasket or sealant bead. Age, heat cycles, over-tightened bolts or a dent from road debris can break the seal, and oil drips from the pan edge. Steel pans can also rust through in salted-road areas. On some vehicles the subframe or exhaust must come off to replace it. How to confirm: With the car on level ground, the oil pan edges are wet all the way around or at one corner, and fresh drips form along the pan seam rather than at the drain plug. Fix: Replace the oil pan gasket. 4. **Leaking crankshaft seal (front or rear main)** (less common), $250-$1,800. Rubber seals at each end of the crankshaft keep oil in while it spins. A front seal leak shows behind the crank pulley at the front of the engine. A rear main seal leak shows where the engine meets the transmission, and replacing it means removing the transmission, so labor is high. Both are more common at high mileage. How to confirm: Oil is dripping from between the engine and transmission (rear main) or is flung around the crank pulley and belt area (front seal), with the top of the engine dry. Fix: Replace the front seal or rear main seal. 5. **Oil filter housing, cooler or pressure sensor leak** (less common), $150-$800. Many engines have an oil filter housing, an oil cooler or an oil pressure sensor bolted to the block with small gaskets or O-rings. These harden and leak, sometimes heavily because the oil there is under pressure. Oil filter housing gaskets are a known weak point on some engine families. The leak may drip onto the belt or exhaust. How to confirm: Fresh oil is concentrated around the filter housing, cooler lines or the oil pressure sensor, often higher on the engine than the pan, and a shop may use UV dye to confirm. Fix: Replace the housing gasket, cooler seal or sensor. ## How to narrow it down at home 1. Slide a piece of cardboard under the engine overnight. Brown or black oil spots under the engine confirm oil; red, pink, green or orange fluid is something else. 2. With the engine off and on level ground, check the dipstick. Top up to the full mark with the oil grade in your manual if it is low, and note how fast it drops. 3. With the engine cool, use a flashlight to find the highest wet spot on the engine. Oil runs down, so the top of the wet area is closest to the leak. ## Is it safe to drive? > **Drive to a shop this week.** A slow seep is usually safe to drive as long as you keep the oil level between the marks and check it every few days. Stop driving and turn off the engine if the oil pressure light comes on, oil is pouring out, or oil drips onto the exhaust and smokes, because low oil can wreck the engine and oil on hot parts can catch fire. ## When does it become urgent? - The oil pressure light comes on or flickers: pull over and turn off the engine. - You see smoke from under the hood or smell strong burning oil after driving. - The dipstick reads below the minimum mark after only a few days. - Oil is pouring, not dripping, or a large puddle forms after a short stop. - You hear new ticking or knocking from the engine along with the leak. ## What will the repair cost? | Cause | Fix | Typical cost | | --- | --- | --- | | Leaking valve cover gasket | Replace the valve cover gasket | $200-$800 | | Leaking oil pan gasket | Replace the oil pan gasket | $250-$900 | | Leaking crankshaft seal (front or rear main) | Replace the front seal or rear main seal | $250-$1,800 | | Oil filter housing, cooler or pressure sensor leak | Replace the housing gasket, cooler seal or sensor | $150-$800 | Detailed breakdowns: [valve cover gasket replacement cost](/cost/valve-cover-gasket-replacement), [oil change cost](/cost/oil-change), [engine replacement cost](/cost/engine-replacement). ## What to tell your mechanic Tell the shop where the drips land under the car, how much oil you have been adding and how often, when the oil was last changed, and whether you smell burning oil or see smoke. They will clean the engine if needed, add UV dye to find the exact source, inspect the gaskets and seals, check the drain plug and filter, and confirm the oil level and pressure. ## How to prevent it - Check the oil level every few fill-ups with the engine off on level ground. - Change oil and filter on schedule, using a new drain plug washer each time. - After an oil change, look under the car the next day for fresh drips. - Fix small seeps before they spread onto belts, hoses and engine mounts. - Use the oil viscosity in your owner's manual rather than switching to random grades. ## Which models get the most engine complaints? | Model | Engine complaints to NHTSA | All complaints | | --- | --- | --- | | [Ford Escape](/vehicles/ford-escape) | 3,905 | 10,274 | | [Chevrolet Silverado](/vehicles/chevrolet-silverado) | 2,167 | 7,658 | | [Kia Soul](/vehicles/kia-soul) | 2,079 | 3,189 | | [Hyundai Sonata](/vehicles/hyundai-sonata) | 2,059 | 4,126 | | [Honda Pilot](/vehicles/honda-pilot) | 1,989 | 5,776 | | [Ford Edge](/vehicles/ford-edge) | 1,944 | 5,306 | | [Hyundai Tucson](/vehicles/hyundai-tucson) | 1,932 | 5,363 | | [Kia Sorento](/vehicles/kia-sorento) | 1,899 | 4,128 | | [GMC Sierra](/vehicles/gmc-sierra) | 1,872 | 5,041 | | [Hyundai Santa Fe](/vehicles/hyundai-santa-fe) | 1,828 | 3,779 | Owner complaints filed with NHTSA in the engine category for 2015-2026 models of 63 popular cars. Counts follow sales as well as reliability, so compare each with the model's total. ## Trouble codes that often go with it - [P0520](/codes/p0520): Engine Oil Pressure Sensor/Switch "A" Circuit - [P0521](/codes/p0521): Engine Oil Pressure Sensor/Switch "A" Circuit Range/Performance - [P0524](/codes/p0524): Engine Oil Pressure Too Low ## Frequently asked questions ### Is it safe to drive with an oil leak? Usually yes for a slow seep, as long as you check and top up the oil every few days. Stop driving if the oil pressure light comes on, oil is pouring out, or it drips onto the exhaust and smokes. Running low on oil can destroy the engine quickly. ### How much does it cost to fix an oil leak? A loose drain plug or filter may cost nothing to 200 dollars. A valve cover gasket runs about 200 to 800, an oil pan gasket 250 to 900, and a rear main seal 700 to 1,800 dollars at an independent shop in 2026, because the transmission has to come out. ### How do I know if it is oil or another fluid leaking? Engine oil is brown or black, feels slick and drips from under the engine. Transmission fluid is usually red or pink, coolant is green, orange, pink or blue with a sweet smell, and brake fluid is clear to yellow. Clear water near the front is often just AC condensation. ### Why is my car leaking oil after an oil change? A leak that starts right after an oil change is usually a drain plug that was not tightened, a missing or reused crush washer, or an oil filter with a doubled gasket. Return to the shop right away. A badly fitted filter can leak enough to drain the engine quickly. ### Will an oil stop-leak additive fix my leak? It may slow a small seep from hardened rubber seals by making them swell slightly, but it will not fix a loose plug, torn gasket or cracked part. Results vary, and it can be a short-term measure at best. A proper gasket or seal replacement is the lasting fix. ### Can an oil leak cause a fire? It can. Oil dripping on a hot exhaust manifold or catalytic converter can smoke and, in rare cases, ignite. If you see smoke from under the hood or smell strong burning oil, pull over, turn off the engine and let it cool before checking. Get the leak fixed soon. ### How much oil leak is too much? A dry-looking engine with a slightly damp gasket is often fine to watch. If you need to add oil between changes, see drips on the ground every day, or smell burning oil, it is time to fix it. Spots that grow larger week to week are a clear sign. ### Why is my car leaking oil when parked? Most oil leaks drip after you park because the oil drains back into the pan and seeps from gaskets at the bottom of the engine, such as the oil pan gasket, drain plug or rear main seal. Hot oil also flows more easily, so drips appear soon after a drive. ### Will an oil leak fail inspection? It can in states with safety inspections, which may fail a vehicle that drips oil or has oil near the exhaust. Emissions tests do not check leaks directly, but burning oil can affect readings and the converter over time. Fixing a dripping leak before inspection is the safest bet. ### Can I fix an oil leak myself? Some leaks, yes. Tightening a drain plug with a new washer, refitting an oil filter, or replacing a valve cover gasket on many four-cylinder engines are reasonable DIY jobs. Oil pan gaskets on some vehicles and rear main seals need major parts removed and are usually shop jobs. ## Sources - [Car Care Council: Car care guide](https://www.carcare.org/car-care-guide/) - [AAA: Approved Auto Repair](https://www.aaa.com/autorepair/) ## Other car problems - [Why is blue smoke coming from my exhaust?](https://diagxcar.com/symptoms/blue-smoke-from-exhaust) - [Why does my car smell like something is burning?](https://diagxcar.com/symptoms/burning-smell-from-car) - [Why does my car crank but not start?](https://diagxcar.com/symptoms/car-cranks-but-wont-start) - [Why does my car hesitate when I accelerate?](https://diagxcar.com/symptoms/car-hesitates-when-accelerating) - [Why does my car jerk when I accelerate?](https://diagxcar.com/symptoms/car-jerks-when-accelerating) - [Why does my car lose power when accelerating?](https://diagxcar.com/symptoms/car-loses-power-when-accelerating) - [Why does my car shake at idle?](https://diagxcar.com/symptoms/car-shakes-at-idle) - [Why does my car shake when I accelerate?](https://diagxcar.com/symptoms/car-shakes-when-accelerating) - [Why is my car leaking transmission fluid?](https://diagxcar.com/symptoms/car-leaking-transmission-fluid) - [Why is my car leaking coolant?](https://diagxcar.com/symptoms/car-leaking-coolant) ## Repair costs - [Valve cover gasket replacement cost](https://diagxcar.com/cost/valve-cover-gasket-replacement): $200-$800 - [Oil change cost](https://diagxcar.com/cost/oil-change): $45-$150 - [Engine replacement cost](https://diagxcar.com/cost/engine-replacement): $4,000-$12,000 ## How long parts last - [How often should you change your oil?](https://diagxcar.com/how-often/change-oil): Every 5,000-7,500 miles ## Trouble codes that lead here - [P0520 Engine Oil Pressure Sensor/Switch "A" Circuit](https://diagxcar.com/codes/p0520) - [P0522 Engine Oil Pressure Sensor/Switch "A" Circuit Low](https://diagxcar.com/codes/p0522) - [P0523 Engine Oil Pressure Sensor/Switch "A" Circuit High](https://diagxcar.com/codes/p0523) - [P0524 Engine Oil Pressure Too Low](https://diagxcar.com/codes/p0524) --- Source page: https://diagxcar.com/symptoms/car-leaking-oil Updated: 2026-11-03 General information, not a substitute for a qualified mechanic.