Gas Smell in Oil?

Just changed my oil at 6k mi/6 mo. -- 2018 OR at 92k mi. -- and the oil had a very noticeable gas smell - oil smelled like gas at the last change too. I've looked over a few other threads and don't see any definitive answers. I commute 25 minutes each way crosstown (avg 40 - 50 mph) 5 times/week to work. 45 minutes to Dallas hwy (70 - 80 mph) there and back on Saturdays. Most other trips are short around town, so I'm hoping it's just that. Engine runs smooth, no idling issues.

Anyone have any thoughts?

(waiting for the inevitable "Normal" from Whippersnapper - hopefully)

 

Sometimes a small amount of gas can get passed the piston rings and end up in the oil when the rings get worn down but it will evaporate when at operating temp. If it's a strong smell then it could indicate a rich fuel mixture which could be a bunch of things faulty injector, dirty MAF sensor, faulty O2 sensor, coolant temp sensor not working properly, damaged piston rings which is rare. Have you seen a drop in your fuel mpg recently. Pull the codes via obd and see if you have any pending codes and look at air fuel ratio also if the coolant level is good.

It could also occur when you drive on I-635 and I-35 in Dallas. I'm not sure HOW it would happen, but those roads are notorious for causing a myriad of issues with cars. Usually they just cause road-rage, but they've been known to cause mechanical issues too!

 

LOL -- yeah, but 75 is worse -- I've got an OBD reader, so I'll have a look. Can't say I've noticed a drastic change in mpg, but I'll see about the codes -- appreciate it.

 

just checked my codes -- doesn't look like I have any. Is this a big enough of a problem where I need to take it in to have a look?

 

My thinking is if you have several short trips before oil change, then that might explain the fuel smell. Especially if the engine doesn't have a chance to warm up completely.

 

Most of my trips are about 20 - 30 minutes, crosstown. But two days ago I had an hour-long trip both ways and haven't driven my car since.

 

All of those seem like they should be long enough to get the oil temperature high enough to boil off fuel vapors.

 

I’m not being a particularly good diagnostician but what I would do is shorten the oil change interval to 5000 next time and get a sample analyzed by a lab like Blackstone. They’ll come back with a fuel percentage among other metrics which I think would be cool info to have.

 

went ahead and changed the air filter (dirty) and cleaned the MAF sensor, so we'll see if that helps anything -- thanks for the feedback guys

 

I would change the oil right away.. number one killer of oil is fuel....
Any combustion engine small amount of fuel will leak into the oil, thus changing the oil frequently is the solution and not every 10K....

 

I just saw a Youtube video by Car Care Nut on cylinder wash-down (Don't Do This To Your Car!), I recommend it. Gas smell in oil is one of the symptoms.

 

If it were me, I would change oil more often....oil is cheaper than parts.

 

Those are not short trips. Short trips that could cause cylinder wash down are 10 seconds to 5 minutes.

 

also maybe check the secondary air pump?

 

why ?

 

have you changed your PCV valve?

 

Quit putting gas in tank or oil in engine?

 

I would check again in a few hundred miles after you change it to see what is what. Shouldn't be seeing issues this soon on a 2018, One would think

 

I think the thin regular motor oil is more volatile. Probably traps more contamination from combustion. I have smelled same thing from mine. Just means it's working. I would recommend a good synthetic everything ar service and oil changes.

 

Sounds like a leaky/stuck injector.

When you turn the truck off, pressure will remain in the fuel line but if an injector is leaking, it will drip that into the cylinder, past the rings, then into the crankcase. Best method is a leakdown test to verify you're dropping pressure, check long term fuel trim for a hint at which side (one bank will normally be negative), then pull fuel rail with injectors attached and see if one has a drip with the key on.

Highly recommend at least the leakdown test soon because aside from being bad for oil, raw fuel is the fastest way to murder your very expensive catalytic converter.

 

Well I have battled a PO430 and I was wondering. It was one of 4 possible causes and I have never replaced a Toyota converter. I thought I felt a little surging a few times and I thought that running low of gas. I priced injectors and they were priced like they are never replaced. I cleaned throttle body last week and it's smooth and light now. My code seems to show up during cooler weather and low dew point. I wasn't pitching parts, so I bought a $26 Bluetooth scan tool and I can reset while I'm driving. It was cool and I started just to turn the wheel. It only did it that once. If I have to replace cats I will use straight pipe or spring for some headers. I think removing cats will help enough. My cousin got an O2 sensor delete kit from California or somewhere and he doesn't use O2s or secondary air pump now. I don't like changing to much as long as it's dependable. I changed something for tires and it led to another which created another change. Now I'm bored and doing what I recommended not too. I'm hot rod guy who likes to tinker and experiment. I just don't have a rod anymore. Trying to makey refrigerator freezer a little more efficient and powerful.

 

May have an issue with one of the piston rings or an issue with spark.

 

I changed plugs at 200k service. I broke a corner latch off air box and keep it zip tied shut. I just recently thought it might have a small leak. I guess I will replace it soon and see. One thing leads to another. I could write a song.