| What it usually is | The installation, not the engine |
| #1 heavy leak | A double gasket at the oil filter |
| #1 slow drip | The drain plug, loose or on a reused washer |
| Fast confirm | Clean everything, run briefly, see where fresh oil appears |
| Often not a leak at all | Oil spilled during the change, burning off |
| Safe to drive? | Residue yes. Steady leak or falling level, no. |
The timing tells you almost everything. An engine that was dry on Monday and dripping on Tuesday, with an oil change in between, did not develop a seal fault overnight. Something about the way it was put back together is letting oil out, and there are only a handful of candidates.
That is good news, because installation faults are cheap and quick to correct, and a shop that caused one will usually fix it for free. This page ranks the causes by where they show up, explains the one that dumps oil fastest, separates a real leak from spilled oil, and gives the check order. For everything else, see the complete oil and engine oil guide.
Drain plug torque and oil filter tightening are specified per vehicle and per filter, so no figure here substitutes for your owner’s manual and the instructions printed on the filter itself. Repair costs for stripped threads vary widely by vehicle, so get a quote rather than working from a general number. A leak that predates the oil change is a different problem, covered in whether it is normal for an old car to leak oil.
Table of Contents
Most common causes, ranked
Seven things cause a post-change leak, and where the oil appears narrows it down fast. The filter and the drain plug are the only two things that were opened, so start there and work outward. The order below runs from the heaviest and most urgent to the ones that turn out to be nothing.
| Cause | Where it shows | The fix |
|---|---|---|
| Double gasket at the filter | Oil pouring from the filter area, often within minutes of starting | Remove the filter, clear the stuck old seal, refit with one gasket |
| Loose or under-tightened drain plug | Dripping from the lowest point of the oil pan | Retighten to the manual’s figure with a fresh washer |
| Reused or missing crush washer | A slow weep around the plug head that keeps returning | A new washer, then correct torque |
| Filter not tightened enough | Weeping around the base of the filter | Tighten per the turn instruction printed on the filter |
| Stripped or cross-threaded pan threads | A seep that retightening does not stop, or a plug that spins | Shop repair. Do not keep tightening it |
| Overfilled oil | Drips from seals and gaskets away from the plug and filter | Drain the excess back to the full mark |
| Spilled oil, not a leak | Burning smell and light smoke, no growing puddle | Clean it off and watch. Nothing to fix |
Overfill is the one that surprises people, because the oil appears nowhere near anything that was touched. Excess oil raises crankcase pressure and pushes past seals that were sealing fine the day before, which is set out in what happens if you put too much oil in your car.
The double-gasket problem
A double gasket is the single worst way an oil change can go wrong, and almost no owner knows to check for it. When the old filter comes off, its rubber sealing ring can stay stuck to the engine’s filter mounting surface instead of leaving with the filter. Screw the new filter on over that stranded ring and two rubber seals are now pressing against each other rather than against metal.
Two gaskets do not seal. They hold just well enough to survive the first start, then let go once oil pressure and heat build, which is why this failure often looks fine in the driveway and turns into a trail of oil on the road. It empties an engine faster than any other cause on this page.
Prevention is one look. A filter manufacturer’s installation bulletin filed with NHTSA makes the first step explicit, instructing installers to always clean the engine oil filter base sealing surface before fitting the new filter. Wiping that surface is what reveals a stuck ring, because you cannot wipe past one without feeling it.
Caution: stop driving if oil is coming from the filter area in any quantity. This is a job for a professional if you cannot safely get to the filter yourself, but it is not something to nurse home. Confirm the old filter still has its rubber ring attached, and if it does not, the ring is still on the engine.
Drain plug problems: washer, torque, threads
The drain plug accounts for most slow drips, and it fails in three distinct ways. Undertightened, it weeps. Fitted with the old crush washer, it weeps regardless of torque. Overtightened, it can strip the threads in the oil pan, which turns a five dollar fix into a real repair.
The crush washer is the part most often skipped. Most drain plugs seal against a soft washer designed to deform once against the pan, so a reused one has already given up the shape that made it seal. New washers cost pennies, and a plug that keeps weeping after being retightened twice is usually telling you it is sealing against a flattened one.
Torque is where the other two failures meet. A plug tightened by feel is a coin toss between too loose and too tight, and aluminum oil pans strip easily. Look the figure up for your vehicle rather than guessing, and stop tightening once the plug seats against a fresh washer.
Hand this one over if the plug spins without tightening, if it will not stop seeping after a new washer and correct torque, or if the previous change left the head rounded. Stripped oil-pan threads need a thread repair or a new pan, and continuing to crank on the plug makes both outcomes more expensive.
Is it a leak, or just spilled oil?
Plenty of post-change alarms are not leaks. Oil spilled down the side of the engine or onto the exhaust during the change burns off over the next few drives, producing a smell and sometimes a wisp of smoke without a single drop reaching the ground. The two look identical for about a day and then diverge completely.
The test takes two minutes. Wipe the drain plug, the filter and the surrounding area completely clean with a rag, run the engine for a few minutes, then look again. Fresh oil in a cleaned area is a leak. Nothing new, with the smell fading over a few days, was spilled oil. Check the ground under where you park as well, because a real leak eventually puts something there.
The burning smell has its own page, since it also arises from causes unrelated to a recent service, and that is covered in how to get rid of a burning oil smell in a car.
Caution: spilled oil on a hot exhaust is a smell rather than an emergency in most cases, but it is not nothing. US Fire Administration data attributes 45 percent of highway vehicle fires to mechanical failure or malfunction, a category that includes a leak or break in a vehicle component. Clean spilled oil off rather than leaving it to cook.
How to fix a leak after an oil change
Work in check order rather than guessing, because the two things that were opened are the two things to inspect. Do this on a cold engine, and if a shop did the change, read the last step first. The whole sequence takes about twenty minutes and needs no parts beyond a crush washer.
- Check the oil level before anything else. Pull the dipstick and read it using the method in how to check your engine oil level. A level below minimum means stop and add oil before the engine runs again. A level above maximum points at overfill as the cause.
- Look at the filter first. Check that it is seated and tight, and that only one rubber ring sits between it and the engine. If the old filter is still around, confirm its ring came off with it.
- Then the drain plug. Confirm it is snug rather than loose, and that a new crush washer went on. A plug that turns easily by hand was never properly tightened.
- Clean everything and run it briefly. Wipe the plug, filter and surrounding area dry, run the engine a few minutes, shut it off and look for fresh oil. Where it reappears is your answer.
- Correct the one thing you found. Retighten the plug with a new washer, or reseat the filter to its printed turn instruction, then repeat the clean-and-run check to confirm it is dry.
- Go back to the shop if a shop did the change. A leak they caused is theirs to correct, normally at no charge, and it is better than working under a car you did not lift yourself.
Caution: never work under a car held up by a jack alone. Use ramps or jack stands with the wheels chocked, and skip the whole inspection in favour of a shop visit if you have nowhere flat and solid to work.
On filter tightness specifically, “hand tight” is vaguer advice than it sounds. The same NHTSA-filed bulletin notes that the subjective hand-tight approach remains common and may result in improper installation, and directs installers to follow the specific turn instruction printed on each filter after the gasket makes contact. What that step should have looked like in full is on the oil change checklist.
Is it safe to drive with an oil leak after a change?
Driving on a light residue is fine, and driving on a steady leak is not. The dipstick decides which one you have. A trace of oil left over from the service, with the level holding steady, is safe to drive to a shop. A leak fast enough to move the level in a day or two risks the engine, and the risk is oil starvation rather than the mess.
Watch the warning light rather than the puddle, because the puddle lags. Chevrolet’s guidance for an “Oil Pressure Low, Stop Engine” alert is to bring the vehicle safely to a stop and not restart it, since running an engine without oil pressure damages it. That instruction applies whatever the cause of the low pressure.
Check the level daily until the leak is fixed, and top up if it has fallen rather than letting it run down between appointments. What a genuinely low level does to a running engine is covered in whether low oil can cause a car to shut off.
Frequently asked questions
Why is my car leaking oil right after an oil change?
A leak immediately after an oil change is almost always an installation issue rather than an engine fault. The usual causes are a loose drain plug, a reused crush washer, or a double gasket where the old filter’s seal stuck to the engine. Check the filter and the plug first.
What is a double gasket and why does it leak?
A double gasket happens when the old oil filter’s rubber seal stays stuck to the engine and a new filter is fitted over it, leaving two seals pressing against each other instead of against metal. Two gaskets cannot hold pressure, so the joint leaks heavily and often suddenly.
Can too much oil cause a leak after a change?
Overfilling can cause a leak, because excess oil raises crankcase pressure and pushes oil past seals that were holding fine before. The giveaway is oil appearing away from the drain plug and filter. Check the dipstick, and drain the excess if the level sits above the maximum mark.
Should I go back to the shop if my car leaks after an oil change?
Return to the shop that did the change, because a leak they caused is normally corrected at no charge. Check your oil level before driving there and top up if it has dropped. Avoid driving any distance if the leak is steady rather than a light residue.
What to do now
Check the dipstick first, then inspect the two things that were opened: confirm the filter has exactly one rubber seal and is properly tight, and that the drain plug is snug on a new crush washer. Clean the whole area, run the engine a few minutes, and see where fresh oil reappears, because that single test identifies the cause faster than any amount of looking. Go back to the shop if one did the change, since the correction is usually free. A light residue is safe to drive on, but a steady leak or a falling oil level means fix it before you drive. Stop and do not restart if an oil pressure warning appears.
For intervals, oil types, overfills and consumption, see the complete oil and engine oil guide, or browse the wider automotive care and repair section.
