What does it mean when the oil in an engine smells like gasoline?

Question

I have an older Chevy s-10 and it is running really rough and stalls out at every stoplight. It won't go over 25 MPH. I tried some carb cleaner in the gas with a full tank. It also just had a new fuel pump installed last summer. any help would be great. Thanks

Truck is a 1984 with a carb.

Answer 1

check the fuel pump, it could be leaking into the engine :(

Answer 2

Vacuum lines:
Check carburetor/choke or What year is it? Only really old vehicles have fuel pumps mounted on the engine block.

Sounds like the choke may be sticking due to a vacuum leak.


First thing is to carefully look at all of the vacuum hoses. If the choke is not proberly releasing, it will run rich. But loss of vacuum can cause all sorts of problems with controls, timing, spark advance, choke etc etc.
Do this first. If it is bad enough, you might be able to hear the sucking sound under the hood.
This is the most likely cause, so do a careful job checking all of the lines. If you pull one off, you can see the effect right away. the engine will run rough or just stall.

Verify that the carburator is bolted down securly. If it is loose, you will also have a loss of vacuum. Symptom, when you try to pull out of an intersection, it stalls or sputters, then picks up power. Loss of vacuum, until the increased engine vacuum can suck it down.


Another " likely suspect" to check is the distributor cap.
If you have an old vehicle with a distributor cap, not electronic spark, that would definately cause the rough running symptom. Remove the top of the cap, and observe the contact points. If they are burnt or eroded, change the cap, and rotor. Should cost < $20. The symptom would be lack of power. Revs ok, but no power, or rough starting if it is really bad. Modern vehicles are all electronic ignition, so no contacts to burn.

How old? S-10s, were introduced in 82, the fuel pump used to be mechanically pumped by a cam inside the motor, through a gasket 1986< ?. If the gasket broke, the oil and gas can mix. It causes the oil to become thin.
This cant happen in a modern fuel injected vehicle. You said it was recently replaced, where? fuel tank ( fuel injection), or on the front side of the engine?
The symptom would be mechanical pinging sounds from the engine due to lack of lubrication.
If you are sure you dont have a fuel pump inside the gas tank, then go to an oil change place, and ask them to observe the oil flow when it is changed, ( do it yourself if you can so you dont have to drive it).
If it pours out like water, it is a good bet that is the problem. The engine is probably damaged due to lack of lubrication. But if you can get the pump/gasket and oil fixed, add a lot of teflon lubricant, such as Tuff-Oil, or one of the more popular brands Slick 50 etc ( use a lot), it can save your engine from further damage, and you might be able to limp along for a few more years.
Unburned gasoline gets into the oil, it is unavoidable, and is one reason you need to change oil often. So oil smelling like gas, may be somewhat normal in an older rough running engine.
Check the oil on the stick, it should be thick like honey, if it is thin like water, you have a problem.


Another problem could be a leaking water pump, that is spraying inside the engine. This moisture will corrode your spark plug connections. Carefully remove each spark plug wire and check for corrosion.
Old spark plug wires can break easily at the connector. If you pull the wire, it will just break, and then you will be in trouble. Go the autoparts store, and get a net set of wires and spark plugs before you start. If your water pump is leaking, it is probably making a whrilling grinding sound like marbles in a tumbler when the engine is cold, and may fade away in a few minutes. Look for moisture on the inside hood near the water pump.

Answer 3

Might have water or gas in the oil. Try a higher octane of gas or try an octane booster every time you fill up. How old is your s-10 and does it in fact have a carb or is it fuel injected? Better check to see what additives you should be using.

Answer 4

You didn't say if there's black smoke coming out of the exhaust pipe. It could be running too rich.
Did you check that the air filter isn't clogged? The carburetor float could have a pinhole in it and be partially sunk (common in Rochester carburetors), or there could be dirt in the needle valve causing the carb to partially flood.
Too much gas in the engine getting in the oil will cause your rings to wear out prematurely. You need to fix this ASAP.

Answer 5

to harass shoot this type of question isn't undemanding gas in oil may well be brought about via many stuff leaking injector, undesirable rings undesirable sensors , leaking heads , undesirable intake gasket , needs to be appeared at via a rep. tec. or keep .do not force it it fairly is risky with the warmth that builds up in a crank case it would desire to reason it to explode I even have certainly seen the place the gas fumes have outfitted up in a crank case and thanks to the temp of the motor and all situations basically precise , there replaced into an explosion interior the crank case and it has blown the valve cover or covers clean off the motor do not force till the challenge with the gas interior the oil has been solved

Answer 6

Gasoline is leaking into the crankcase. It could be the carburetor. More likely, if it has an engine mounted fuel pump It could have a ruptured diaphragm allowing raw fuel to drain into crankcase. I have seen this several times. Good luck.

Answer 7

It sounds like you have a leak somewhere which is getting into your engine. That is going to be costly $$$$$. That means you will have to pull the engine apart to find the source of leak and fix it and clean it, before putting it back together to start it up again.

Answer 8

Fuel injected? you have groves or bad rings in cylinder(s) letting raw fuel blow past the rings into the crankcase when on the compresion stroke(before igniting) or the manifold gasket is leaking or cracked manifold.

Answer 9

your fuel pump has a worn diaphram replace the fuel pump and change your oil and filter.

Answer 10

the carb. is flooding and going down in the oil.