Gas smell in engine oiil

[deanna5051]

I have a 1977 Glastron SSV177 that I have been restoring ,I changed oil and filter about two months ago when I started the project and haven`t had it in the water yet only started it three or four times to listen run and tune it a little, today I checked the engine oil and it smells like it has gasoline in it , can any one tell me what might causing this? Thanks for any replies.

 

[HT32BSX115]

Re: Gas smell in engine oiil

I have a 1977 Glastron SSV177 that I have been restoring ,I changed oil and filter about two months ago when I started the project and haven`t had it in the water yet only started it three or four times to listen run and tune it a little, today I checked the engine oil and it smells like it has gasoline in it , can any one tell me what might causing this? Thanks for any replies.

Howdy,


Well aside from someone dumping gas in your oil when you aren't looking, it's difficult to say without knowing what you have.

I am going to go out on a limb and assume that you have a stern drive with an automotive (type) engine. If you do, you probably have a mechanical fuel pump that has a hole in the diaphragm that is allowing fuel into the crankcase...

I can probably be a little more specific when you reveal what engine you have.


Regards,


Rick

 

[NHGuy]

Re: Gas smell in engine oiil

It's also possible you have fuel dumping from your carburetor. It then seeps by your rings into the crankcase oil.

 

[badkins50]

Re: Gas smell in engine oiil

we had this trouble with our previous boat when the mechanical fuel pump went bad. ours would crank over as if it was going to start but never would and when done cranking it would immediately just dump the gas down the carb. ours was so bad, when i took the fuel pump off and manually operate it, a puff of black stuff would come out. good luck and let us know what you are working with.

 

[NHGuy]

Re: Gas smell in engine oiil

To add a little to what badkins said. If you have a marine mechanical fuel pump with the transparent tube from the pump to the carb look at the tube. If it has fuel in there the normal diaphragm has failed and the fuel is being "saved" from pouring into the bilge by the safety system which routes the fuel to the carb through that tube. I don't know enough about carbs to comment but I believe it then vents within the carb. Possibly right into the intake.

 

[stackz]

Re: Gas smell in engine oiil

as said above...

fuel pump diaphram could be bad, carb could be dumping fuel past the rings.

other thing I've seen is a bad intake manifold gasket that allows fuel into the lifter valley and thus into the pan.

 

[John_S]

Re: Gas smell in engine oiil

I don't know enough about carbs to comment but I believe it then vents within the carb. Possibly right into the intake.

Yes, it drains down over the butterflies right into the intake.

Also could be a sunken float or stuck open inlet needle valve. It will overflow and go down the carb barrrels into the intake.

 

[deanna5051]

Re: Gas smell in engine oiil

Sorry about that guys ,the engine is a 140 Mercruiser, mechaniccal fuel pump and a Rochester carb.
Thanks