engine oil smells gas

Oil Smells Like Gas – 6 Reasons Why Gas is getting into the Oil

In Engine Oil by Magnus Sellén40 Comments

Did your engine oil have a strong smell of gas when you replaced your engine oil?

This is actually a pretty common problem when it comes to gas engines. But how serious is this problem and how do I fix this issue and prevent it from happening again?

In this article, we will go through the causes of why your engine oil smells like gas and how you can avoid it in the future.

Causes of why gas is getting into the oil

gas getting into oil

Your engine contains cylinders and pistons. The pistons contain piston rings which will seal the combustion chamber from the crankcase. If the fuel mixture inside the cylinder chamber won’t ignite correctly or the piston rings are worn, the fuel can flow down into the oil pan.

However, even after all that sealing, a small amount of fuel getting into the engine oil is actually very normal and nothing to be worried about. That happens as you drive your car routinely as the engine is constantly receiving fuel and the oil is constantly being circulated during the combustions.

This problem arises either if your car’s fuel injectors gets stuck in the open position, spilling gasoline or if your carburetor is letting in an interrupted supply of fuel, even when the gas pedal is not being depressed.

Here are the 6 most common causes of why the gas is getting into the oil

1. Fuel mixture too rich

The main cause of why your gas is getting into the engine oil is that your fuel mixture is too rich. If your fuel mixture is too rich, the combustion chamber won’t ignite all of the fuel and this will cause the fuel to run through the piston rings down into the oil pan. There could be several sensors or other problems causing the fuel mixture to get too rich. Read the trouble codes with an OBD2 scanner to see if there are any stored trouble codes which could indicate where you should start your troubleshooting.

Normal causes of rich fuel mixture are the Mass air flow sensor, Coolant temperature sensor, O2 sensor, MAP sensor, and the intake air temperature sensor. Go through the links to our post about the specific sensors to learn more about them.

2. You only drive for short distances

Gas is always running down into your oil pan on almost all car engines, more or less. When your oil temperature gets high, the gas will come out as vapour from the engine oil. If you only drive for short distances, the engine oil will not reach a high enough temperature to vaporize the gasoline and you will fill up your oil pan with gas for a while. If this happens, you should replace your engine oil and filter. If you know that you often only drive for shorter distances, it’s recommended to change the engine oil at shorter intervals than normal.

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3. Bad piston rings

If your piston rings are bad, more fuel will run through the combustion chamber into the oil pan. However this is not a very common problem and it’s very difficult to repair as you have to take the whole engine apart, so I recommend checking the other things in this list before. A way to check the piston rings is to do a compression test or a leak down test.

4. Misfires

A Misfire happens when the air-fuel mixture is not getting ignited correctly and the combustion cycle is disturbed. Because the air-fuel mixture is not getting ignited, the gas can wash your cylinder walls which will cause the compression to be lowered and more blow-by through the piston rings will happen. This can cause the gas to pour down through the piston rings and fill your oil pan with fuel.

5. A faulty fuel injector (newer cars)

Fuel injected vehicles have small injection devices which provide the engine with the fuel it needs. These injectors are operated by a solenoid, further controlled precisely by a computer which lets just the right amount of fuel inside the cylinders. Since solenoids are mechanical, they can often malfunction and if the solenoid gets stuck in the open position, gasoline will find its way inside because the substance is watery, and mixes with the oil. The gasoline, in the excessive amount which flows out, will eventually seep down in the oil pan and mix with the oil as your car is running.

6. Faulty carburettor or settings (older cars)

Cars with carburettors are different. The fuel mechanism is handled by a diaphragm and controlled by the gas pedal mainly. Since that is too, mechanical, the butterfly valve that controls the air flow can get stuck which will let the fuel in according to the mixture ratio. That will also let gas get into the oil and cause this problem. At that point, similar to fuel injected cars, the excessive gasoline will go down into the oil pan and mix with the oil.

What does it mean when we say that gas is mixing with the engine oil?

Have you ever realized that when you are getting your car’s engine oil changed, you get a strong smell of gasoline as the old oil pours out? Do you often wonder why that happens? Since gas and oil are the two active ingredients that are fed to your car’s system, it is possible that the gas may be getting into the oil which is why you are getting the smell of gasoline as you change your car’s engine oil or just take out your dipstick to check the oil level.

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While it is normal for a small amount of gas to get into the oil, too much oil dilution with the gasoline can become a major problem. Is the smell so strong that it feels like the gasoline is flushing instead of oil when getting the oil changed?

Symptoms of oil and fuel mixture beyond the normal amount

If you are unsure whether the mixture of gas and oil isn’t normal, here are a few symptoms and signs you can look for that can tell you whether there’s a problem with the car or not.

  • You can smell a strong odour of fuel as you are driving the car
  • Your car emits an opaque white smoke from the exhaust rather than a clear smoke
  • Your dipstick shows that your oil is either overflowing or the level is increasing without actually adding any oil
  • Your dipstick smells more like gasoline than oil
  • The oil on your dipstick drops off like water droplets
  • The oil pressure gauge shows low oil pressure
  • You notice that, while changing the engine oil, the oil seems not so viscous

If you encounter any of these symptoms, it may be that there’s an excessive amount of gas getting into the oil in your engine which isn’t normal. A rather easy way to tell if your car is using too much fuel is that your car will emit thick white smoke.

That is due to the fact that fuel that is not burnt properly during the combustion cycle will tend to ignite later when on its way out of the cylinder. Also, since oil is viscous and gasoline is not, if you realize that your engine’s oil is thinner than it should be, even after a long time of use, there’s a high chance that it’s the gasoline that is changing the viscous properties of the oil.

How do you tackle the problem?

Too much gas getting into the oil in your engine is never a good sign and so the first thing you should do is immediately get your car checked by a mechanic for the symptoms above if you do not have the knowledge yourself. If everything looks okay, it might be your piston rings that are worn out. The job of these seals is to keep the oil from the oil pan from getting inside the cylinder and keeping the gasoline from dripping into the oil pan.

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These seals are worn out over time and need to be replaced. The best sign to look for, which should tell you about the piston rings is to check the smoke your car is emitting. If the smoke is thick and black, it means that your car is burning oil. If the smoke is thick white, that means your car is running rich and burning too much gasoline.

After getting your piston rings checked and replaced, change your engine oil to prevent engine damage.

It’s recommended to carry out a compression test to check your piston rings’ sealings. Here is a video of how to do this:


If you do only drive for short distances, it’s common that you will get a lot of gas in your engine oil and in this, you have to replace the engine oil immediately and perform engine oil changes more frequently than normal if you will continue to drive for only short distances.

Read the trouble code memory for any signs of broken sensors or other things that will cause the engine to run rich.

If you have any other questions, you are welcome to apply a comment below and I will answer your questions as soon as possible.

40 thoughts on “ Oil Smells Like Gas – 6 Reasons Why Gas is getting into the Oil ”

  1. Minor edit suggestion.In part 2 you said won’t reach high enough temp to evaporate the oil,not the gasoline I think you meant

    1. I have a 1930 Ford with a Chevy 350 engine board out 60 over with a tunnel ram into fours I was told those carburetors are too much for that engine could I reject it down to get less gas into the engine

    2. I called the mechanic but he hasn’t called back. Is it ok to drive the car? When you can smell the gas on your dip stick. I don’t want to throw a rod. The shop is a mile or so away.

      1. I had a pcm driver for injector 4 burn out in a chrsler town and country due to the injectir harness melting as they are notorious for. The injector was stuck open and I lost power with a large white smoke screen coming from my exhaust. I replaced the pcm and changed the oil because it was saturated with gas. But now when my van comes to operating temp I get a funky smell of burning under the hood and white smoke around my pipe coming off my exhaust manifold. I can’t see any leaking but when I checked my freshly changed oil it’s thin again and definitely full of gas. I’m lost at this point. Any suggestions? And ironically it runs withou any misfire but I’m leary of the smoke and the oil being diluted with gas to drive it anywhere.

    3. I have a 2006 vw passat 2.0 fsi little of blak smoke from my tailpipe

    4. I changed my fuel pump and I started the blazer and let it run for about ten minute. I turned it off but a short time later I tried to start it. It started but ran really bad when it died I could not start it. It was frooze up I took a plug out and gas poured out when I drained the oil it was mostly gas

  2. What is considered small distances? I am having this issue . I drive about 5 miles stop for 15 minutes and then drive back..twice daily..

    1. Author

      Yes, that’s absolutely short distances. The oil is getting heated much slower than the coolant and to reach full oil temperature it can take more than 15 minutes of driving to heat it to the optimal temperature to vaporize the gas correctly.

  3. What would be the suggested repair? I have a 2017 CRV with 1.9 TC engine. There was a piece in Consumer Reports about a problem with this engine getting ga in the oil.
    I’ve checked the oil and the level seems a high.
    Trying to figure out what repairs I should insist on beyond root cause.

    1. Author

      Gas getting into the oil is not an easy problem to solve. It’s most often caused by bad piston rings. If the dealer does not have a technical service bulletin for this problem yet, I would recommend replacing the engine oil often and make sure to not only drive for short distances.

  4. Dear Magnus,
    I have a same issue with my car, even fuel consumption is too high as comparing with normal car.
    i have 1jz-gte non vvti, and while driving i smell strong odor of fuel moreover when i stop the engine at idle position the white smoke came out from tailpipe. compression test has been done and it result fine to me on all cylinders. please suggest me on it.

    appreciated well in advance.

    1. Author

      Do you have OBD2 in your car? If so, read the trouble code memory with an OBD2 scanner and check for any misfires or fuel adjustment problems like a bad sensor. A car that is running rich will cause a lot of gas in the oil pretty fast.

      1. Hi, no OBD2 available. actually running with stock ecu and 1jz has been swapped in my mark 2.

  5. My 16 year old son has a 1977 Ford f150. Gas is getting into the oil. One person said it was probably the fuel pump and someone else said it was probably the carburetor. It even shot fire out from somewhere under the hood this afternoon and my son had to put it out. Would your information be different since we are talking about a old vehicle. It has a 400 big block. Help please. This truck has been a hand full.

    1. Author

      It sounds like your car is getting too much fuel and it could absolutely be caused by a bad/bad adjusted carburetor for your car. If the engine is backfiring through the carburetor there might also be a faulty adjusted timing or leaky intake valve.

    2. The oil smells like gasoline and there is a slight leak I am 3,000 miles over on my all change would this be fixed with just a new filter and oil change or do you think there is something else going on? Thank you

  6. I have a 2019 BMWK1600 motorcycle. It has an inline 6 cylinder motor and I have discovered a thick white emulsion at the dipstick in only 2000 miles from new. In that time period I have taken long rides, day trips and commute to work on it about 5 miles each way on a combination of surface streets and freeway. The dealer has looked at it and is saying that it is condensation due to the short trips. I had them change the oil and and have since been riding at higher than normal rpm for 20 miles at a time minimum. It has come back in under 100 miles, I will be sending the oil out for testing soon. What is your opinion of the issue I am having? What should I be concerned about? Engine longevity, failure etc.

    1. I have a simplicity riding mower it has Kohler engine the gas is getting into oil and shooting it out through the breather is this mean the ring are bad?

  7. This is more of a question than a comment…so i have a 11 Hyundai Santa Fe and it has a shake to it kinda like a broke belt in a tire or a bubble on the tire but when i let off the gas it smoothes out so its not my tires and it also whines really loud accelerating and it don’t stop when i let of the gas it just whines down what could that be? Also i checked my oil this morning and it was bubbley on my dip stick and smelt like gas really strong and when i wiped the oil off my dip stick my dip stick was kinda tarnished like you could see how far up my dip stick it went any ideas at what could be causing these problems? I have no clue about an engine and i can’t get it checked at advanced autos because it is not throwing any codes and my check engine light is not on…please help me thank u

  8. Hello,

    I have a 2008 BMW X5 and all the sudden when I turned on white smoke started to come out from tail pipe with a very strong smell could feel it on my eyes, nose and difficult to breath almost like a burning feeling something I’ve never experienced very strange, then after that it seemed like my car didnt have the same power and haven’t really noticed the white smoke after that. We did oil change right away and can smell gasoline in the the engine oil. No check engine lights on or anything my car was fine prior. What could this be? I know its difficult to diagnose but where do I start? 😔 please help.

  9. Hi,

    I drive a 1999 Jeep Grand Cherokee. 205,000. Miles. I was checking my oil and I noticed that it smelled like gas. The last two times I bought gas I put the highest octane gas in to kind of clean things out. My car ran better, but my oil smelled. Not sure if this was the cause, higher octane, or it’s been happening and I didn’t notice. I’m not omitting any smoke from the car but the oils seemed thin on the stick. I only drive about eight minutes to work. Dumb girl question, should I put a fuel injectors cleaner in? Thanks.

    1. Hi im michael, im encountering this problem to my 2000 B3 gasoline engine. Where excessive amount of gasoline mix with oil in my oil pan. And the cause of the problem was mis fire of my spark plugs and rich fuel mixture setting of my carburator which already have it replaced. My question now is should i required have my piston rings also to be replaced?

  10. Hi, I’m having an issue with my 1987 Buick park Avenue. I changed my fuel filter, spark plugs, thermostat, and did a oil change and a rack and pinion. After the rack was put in, we test drove it and it started leaking out honestly I’m not sure but eventually did stop. My dad thought water pump but he’s getting old so I’m not sure he’s right. At the same time I’m smelling gas in my oil and Ive never had it smell like that. It’s so strong. Someone told me to change fuel injectors and I’m pretty sure he said ti change the fuel modulator regulator? Something like that I can’t remember the exact name he said. What would you suggest? Please help, I live in mn and it’s about to get really cold outside. Thank you very much!!!😊🤙

  11. What you mentioned above it what I have experienced and now am loosing hope about the I have redone the engen 2 times checked and changed multiple of sensors still the same problem my car oil smells gas a lot and it running like water if I take off the deep stick realeses different types of smokes in my pipe if you touch a pipe is black black some other days it realeses white smoke sometimes it dark and now even my hydraulic lifter are always making noise even if I changed the oil recent the oil changes into black dark black in a space of two days then it diluted by gas re-done the engen check engen light is still there with the electric power sign inside⚡ please help man even the smoke in the pipe smell gas mixed with oil my car is astra 1.6 astra G 16valve

  12. Toyota Camry I’ve had a problem with him like maybe 6 months ago 7/8 months ago and why I hadn’t replace the motor okay we put another motor I went out of town but before we not chili check the oil the everything I check everything that needed to be checked so for a trip cuz I had a drive for like almost an hour so I was worried you’re coming home out of the blue the car got hot and now I can’t get it to start for you at the old doesn’t look like it has its milky it just it smells little bit of gas but it didn’t like overheat majorly it just overheated and I in the car shut off and I couldn’t get one start after that why

  13. I have a supercharged f150 46,000 miles and noticed I’m into the boost a lot more often when going uphill or under the slightest load. Transmission also shifts way to soon and lugs the motor causing boost to go up at low rpms. Changed the oil at 5K and real strong odor of gas. Can smell raw fuel on cold starts as well. There is no misfire, new coil packs and plugs. Motor is still very strong with good oil pressure.
    Going to try new injectors and go from there.

  14. My Ford F=150 had a recall, 19S07. We took it to the dealership and also got an oil change. The following day but the truck wouldn’t start. They said, fuel pump, fuel injector. They don’t know for sure. They want over 3,000 to fix it. The truck never gave us a “check engine” light or any other issues that would make us suspect there was anything wrong. We put 1000 miles in the week we took the truck in.
    The truck cannot be driven. Could the dealership have done something to cause the issue with my truck? Thanks.

  15. I bought a 1994dodge ram 1500 recently with less than 10,000 miles on the new engine. It sat for 2 years. I changed the gas, added seafoam, changed the oil change and noticed it was real thin with strong gas smell. The throttle body was caked with black deposits. So I cleaned it. I haven’t tried starting the truck yet since all this work was done. Before, it would start, black smoke and rough idle and then it would stall. I couldn’t turn it over until the next day. Do I need to do anymore work to it? Maybe clean fuel injectors or was the bad oil the reason for rough idle?

  16. So I have a 2001 Jaguar with the V8 in it and my engine oil smells like gasoline I’ve changed the fuel pump and the fuel sending unit I have not changed the oil yet this occurred to me and my car actually blew white smoke at the back end of it but now it will not start after I changed both of those parts out should I change the engine oil and then see what happens what is your suggestion the car cranks over but won’t start very frustrated

  17. I drive an Audi A3 2011 model, In the morning when i start my car the car Idle is not stable it goes up and down and also the car sound like it has a misfire when its cold and also when I change oil on my car the oil smells petrol,
    I did a scan and i got the following error codes, can you help explain this codes for me.

    1. Oxygen (Lambda) Sensor, B1 S2
    P1114 – Internal Resistance

    2. Bank 1 System To Rich off idle
    P2178 – 000 Intirmittent

  18. how long and how far before the engine is hot i have a smell of gas in oil and the level is past the full mark in the stick the oil is new still viscous but im worried about it

  19. I own a 2016 Chevy Silverado 4×4 with a 5.3litre engine. When the temperature gets below 20 degrees Celsius My engine fills with gasoline an I’m not talking about a few ounces but litres of gas. Once it was 1.5 inches above the full mark. I figure 2 litres at least. On the way to dealership the oil gauge needle was bouncing. I’m fighting with GM with this but they blame me instead of fixing it. Last oil change there was a guy with a 2019 with the same 5.3 he changed his oil 600km’s before. I heard this is a problem with these engines but GM won’t acknowledge this. Any sugestions

    1. Same problem on my 14 I found a recall for high pressure fuel pumps leaking under the intake for 14&15 but ofocurse they say my vin # isn’t included . The Chevy techs know what it is they’re playing dumb . I’m not sure if this is my problem but it’s the only thing I can find .

  20. I have a 2012 Ford Escape that is making ticking noises and the dip stick smells like oil. The tick gets louder when Iightly push the gas and then let off. I’ve had it checked by two different places who both said at first nothing wrong and then the first place said a cracked block but they didn’t actually take it apart and diagnose it. They just guessed from the noise.

    1. Try a thicker oil it might work and watch if your oil level goes up if it does than you might have gas going into oil. Ticking noise is most likely a lifter not getting its oil or oil to thin.

  21. I have a 1999 Honda prelude SH and getting a some what strong smell of gas in my oil, I drive short distances so maybe that’s why, about 3 mile street distance round trip in and out of work 5 days a week. I do have a code that pops up P0441 maybe that has something to do with it. Maybe someone can shine a spot light on what might happening with my car??

  22. I have a 2014 Silverado . I have codes 172&175 running rich on banks 1&2 . Threw CEL. For 3 days went away . Seems fine now but the inside of my oil cap smells like a old lawnmower (gas) . I found a couple of videos showing that the Highpressure fuel pumps have a tendency to leak in these engines (5.3s) do you have any experience with this situation?

  23. I have a Suzuki ATV, and I was changing the oil and there seemed to be a fair amount of gasoline in the oil, and the spark plug was black, and it would not start. I am going to change the plug, oil and filter, do you think I have a problem. Could it be the fuel mixture being to rich?

  24. Due to a very high demand and high ammount of comments, you have to wait for some time for your car questions to get answered. If you want to get fast answers from a certified master technician you can ask your questions here:
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