Motor oil and gasoline both have distinct smells, so it’s alarming when the two seem to have mixed together. When oil smells like gas, it could be a sign of something wrong.
In this guide, we look at what causes the oil to mix with gasoline and we show you what to do about it. Additionally, we answer a few of your top questions since we have the mechanical expertise to deal with these problems.
What Causes Engine Oil To Smell Like Gas?
In normal circumstances, the motor oil shouldn’t smell like gas. This normally happens because of short driving distances or a lack of oil changes. It can also occur because of a rich fuel mixture, bad piston rings, a faulty fuel injector, or a failing carburetor.
Here is a more detailed list of why your oil smells like gas.
1. Frequent Short Distance Driving
During normal drives, gas can drip down to the oil pan. This isn’t anything alarming, as the gas vaporizes once the oil pan starts to heat up.
However, if you are only traveling short distances, the oil won’t ever get hot enough to vaporize the fuel. What you are left with is a gasoline smell.
2. Too Rich Fuel Mixture
For combustion to occur, there must be a perfect balance between air and fuel. When there’s too much gas, it’s defined as a too rich fuel mixture. The opposite would be if there was too much air, which would be a too lean situation.
Problems with a sensor can be to blame. Your system relies on a multitude of sensors to balance the mixture. If the intake air temperature sensor, O2 sensor, coolant temperature sensor, mass airflow sensor or MAP sensor malfunctions, all of these can lead to a rich-running situation. As a result, the gas will build up on the oil pan as it seeps through the piston rings.
3. Bad Piston Rings
While we are on the subject of piston rings, you must consider what happens when these get damaged. If there’s even a small amount of damage to the rings, fuel can leak into the oil pan, leaving behind a fuel smell.
While the rings don’t become damaged too easily, this problem can be a bear to deal with. A compression test would be necessary, which we discuss in detail further down in the guide.
RELATED: 4 Symptoms Of Piston Rings
4. Faulty Fuel Injector
Today’s cars utilize fuel injectors that ensure the engine has the right amount of gas. A solenoid commands the injectors to regulate the flow and the computer calculates what’s needed.
Extra gas leaks into the oil when the solenoid gets broken. If it remains in an open position, gas will also leak and blend together with oil. The more it occurs, the stronger the gasoline smell is. Bad injectors can also lead to engine performance issues, even a possible misfire.
RELATED: 8 Symptoms Of A Bad Fuel Injector
5. Oil Change Not Done According To Schedule
Even under normal operating conditions, a small amount of gas can make it into the oil. There don’t need to be any major mechanical issues for this to occur. Because the fuel is minimal in the oil, you normally wouldn’t smell it.
However, if you aren’t performing regular service and changing the oil, the fuel smell can start to compound. What you are left with is a gasoline smell, along with dirty and contaminated oil. For this reason, it’s always best to follow the manufacturer’s recommended maintenance schedule outlined in the owner’s manual.
6. Faulty Carburetor (Older Vehicles)
Today’s modern cars don’t have a carburetor, but once upon a time, they all came with one. If you have an older vehicle, you must consider that the carburetor may be to blame. If the motor oil starts to smell like fuel, the carburetor may be damaged.
Inside the carburetor, the float is responsible for allowing fuel into the engine. If the float sticks, too much fuel mixes with air. As the fuel makes its way into the oil pan, you will start to smell that gas stench.
How To Fix Oil Smelling Like Gas
Once you smell gas in the oil, it’s time to take action. Hopefully, the problem is nothing serious, allowing you to perform a quick fix and get back on the road. However, if you don’t resolve the situation, it could turn into something larger.
Here are the steps we would take as professional mechanics.
1. Drive More Often And For Longer
It’s important to start off by evaluating how you drive. Driving short distances isn’t good for the car and it can lead to a gas smell. To change this, consider combining trips, so you are out for a longer period at once.
You need to drive long enough for the engine to reach a higher operating temperature. That’s when the gas will start to burn out of the oil pan, so you no longer have that smell anymore.
2. Check Trouble Codes
If there’s a Check Engine Light on, you want to read the codes to see what’s causing the problem. Plug in your OBDII scanner and see what codes show up. You may also use freeze frame data to determine what’s going on.
If you aren’t familiar with the DTCs, you can reference the information with our online code library. Perform whatever fix seems relevant and reset the codes to see if the problem resolves itself. If not, you should continue working through our steps.
3. Check Compression
An engine compression test checks the pistons’ and valves’ ability to compress the air and fuel mixture. You don’t need a lot of mechanical experience to perform the test, but you will need some specialized tools.
Here are some basic steps to follow.
- Gather your equipment: You don’t want to search for your tools after you get started. You can rent one locally if you don’t have a compression tester.
- Disable fuel/ignition: The engine cannot run during the testing. Older vehicles with a distributor can be disabled at the coil. Fuel-injected cars need to be disabled at the fuel system. Look in the owner’s manual to find the fuel pump fuse and remove it.
- Take out the spark plugs: During the testing, you don’t want compression strokes hindering the spinning.
- Start the test: Hook up the compression testing tool. Spin the engine at least six times for the gauge to read properly. Keep your hands clear of all pulleys and belts.
- Record your readings: Write down the readings as you go for reference. Most gas engines have a compression between 125 and 175 PSI.
- Evaluate the reading: If one reading is lower than the others, there might be a problem with a cylinder. If you have several lower numbers, other engine issues may be present.
Remember to hook everything back up after the compression test. If you’ve disabled the fuel or ignition system, it’s time to put it back together.
4. Change Engine Oil
If it’s time to change the oil, you may consider seeing if this fixes your problem. Most cars with conventional oil need to be changed every 3,000 miles. If you use synthetic motor oil, you may be able to go 7,500 miles or more. Check the service schedule for your particular car model to get accurate information.
Here are some basic steps to consider.
- Jack up the car and secure it on jack stands.
- Place an oil drain pan under the oil plug and open it.
- Allow the oil to drain out completely.
- Remove the old oil filter.
- Put the drain plug back in.
- Install the new oil filter.
- Fill the system back up with oil.
- Check the levels and top off as needed.
It’s also important to check for leaks. If you notice any leaks, you want to fix them before the problem gets worse.
5. Contact A Professional
If you need to find a mechanic, talk to your family and friends to see who’s recommended. The Federal Trade Commission also recommends asking to see current licenses from the mechanic.
You may have to pay for the diagnostics, but the shop should give you a detailed estimate before performing a bunch of repair work. Sometimes, it’s just better to pay this bill versus banging your head against the wall trying to figure out what’s wrong.
Does gas in the oil damage the engine?
In small amounts, gas in the oil won’t hurt the engine. However, if there’s an excessive amount of fuel in the oil, it can reduce the viscosity. With thinner oil running through the motor, the internal parts don’t get the lubrication needed and there’s minimal protection, leading to a higher chance of damage.
How do you know if gas is in your oil?
The most obvious symptom is the smell of fuel in the oil. You may also see white smoke coming from the exhaust and the oil pressure gauge may read slightly lower. Finally, if the oil level is rising without you adding more, it could be due to fuel leaking into the system.
How do you test for gas in the engine oil?
The sniff test may be all that’s needed. If you smell gas in the oil, it’s probably present. You can also put a few drops of the oil from the dipstick on a piece of cardboard. If there’s any gas in the oil, two rings will appear on the cardboard within minutes. The outer ring is the fuel with the oil in the middle.
What happens if gas mixes with oil in the engine?
Nothing will happen from a small amount of gas in the oil. However, when there’s lots of fuel in the oil, viscosity is reduced. With thinner oil, the internal parts receive less lubrication, so there’s minimal protection, leading to a higher chance of engine damage.
How do you remove gas from oil?
First, you have to figure out what’s causing the problem and fix it. There’s no sense in doing anything else until you stop the flow of fuel into the oil. Once that’s done, you can change the oil and filter. With fresh oil in the motor and the problem resolved, you shouldn’t notice any more fuel infiltration.
Conclusion
As professional mechanics, we are constantly dealing with strange smells coming from vehicles. One that always catches our attention is the smell of fuel in the oil. These two substances aren’t made to be mixed together, so quick action is required.
If you can repair the problem on your own, go for it. We always encourage saving money by avoiding a visit to a repair shop. However, if you aren’t familiar with these systems or you are unsure how to fix them, you should visit a local mechanic. A lot can go wrong when you work with the engine, so don’t take any chances.
47 thoughts on "6 Reasons Your Engine Oil Smells Like Gas & How To Fix it"
JustSumDad
A common problem with older engines with mechanical fuel pumps is that when the diaphragm cracks they can dump fuel into the crank case.
Magnus Sellén
True, thank you for your input!
Venus Young
Hi, I have a 2005 Ford Explorer, I have a problem with it cranking, it will idle but it won't crank, I've had someone tell me it was the fuel pump to the fuel filter to now it's gas pumping into my cylinders and into the oil, that's the main reason it's not starting. What are the reasons why gas is pumping into the oil?
joey dick
i have 2004 explorer 4.6 l i have same problem just happen gas in oil, it went to shut down mode, so did you get yours fix ? if so what was the fix?
raghib barat
I have a 2003 Civic with 172500 miles. After I replaced the head gasket, lot of exhaust gas is now mixing with oil, and also almost a quarter of oil is lost in 1000 miles of driving. There is no oil leaks. I also noticed a lot of oil sitting in a couple of cylinders. I only drive it once a week or less now for short distances. If this is could be worn piston rings or cylinders then why am I seeing only after the head gasket change? Previously I used regular 5w20 oil and now after the head gasket change, I have been using high mileage synthetic blend oil. Will it make a difference if I switch back to regular oil?
Kim Thomas Adams
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? Thanks!
Michael
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?
Joshua torres
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??
Beverly Hodge
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.
Ron
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.
Renald Ouellette
I own a 2016 Chevy Silverado 4x4 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
Michael
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 .
gary
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
Vusi
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
Ora coates
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
Liviu
I am experiencing the same thing with my BMW 318i, did you fix your issue in the end?
J Brown
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?
Nancy
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.
Steve
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.
Jose Benavente
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
Bandile kubheka
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
Jeanette
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!!!😊🤙
Missy
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.
Michael
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?
Sophia
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.
Ashley
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
Tom H
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.
Fank Chavez
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?
Freida Worley
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. Freida
Magnus Sellén
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.
Christopher N Baker
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
Fahad Hussain
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.
Magnus Sellén
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.
Fahad
Hi, no OBD2 available. actually running with stock ecu and 1jz has been swapped in my mark 2.
Cindy
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. TIA!
Magnus Sellén
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.
stefania
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..
Magnus Sellén
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.
scott
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
Magnus Sellén
Thanks a lot for your report scott. It's edited now, thanks! :)
Gene
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
Marla Rasmussen
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.
Jennifer Arp
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.
Jillian Holiday
Thank you for your wonderful knowledge and help !
Given
I have a 2006 vw passat 2.0 fsi little of blak smoke from my tailpipe
Al Prejean
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
yolanda
My name is Yolanda I checked my oil and it smell like gas and its like a yellow brownish color it runs good its not making no noise there's not white smoke coming out I not having no problem with it its the oil dip stick that xmells like gas thats the only problem I have