Gas smell in Oil

[whitlock87]

I have a 2004 Marine Power 5.7 335 hp
First oil change done by dealer (no Problems)
Second oil change done by me at time of winterizing (again no problems)
I just got back from Lake Mohave and the engine has 153 hours on it.
The oil in the drain pan has a slight gas smell to it, but the oil in the oil filter smells like straight gas.

Now I know there shouldn’t be gas in the oil, but why does the oil in the oil filter have a stronger gas smell then the oil in the pan?

On our last trip, we had no problems; the engine started very fast every time and ran very smooth and strong. After changing the oil and making sure that the block was well vented, I started the engine. Again no problems started right up and idled smooth.
Also I was watching to see if I would have any smoke coming out of the exhaust, and there was none.

If I had a bad ring, shouldn’t there be some smoking?
If an injector stuck open, I also should have black smoke at time of start up.

I am hoping that someone might be able to shed some light on this for me.
For now I am keeping a very close eye on the oil level and smell.

Thanks David

[whitlock87]

Just incase anybody is following this.
I talked we Lee over at Marine Power, He thinks that I might be washing out my rings. (The engine is running to rich) So he wants to have my ECM flashed (delete its program, and reprogram it)
Seeing as he and I both will be at the Tige reunion next week in Parker, he is going to bring some equipment with him and take care of it there
(Not bad, I wonder if you would get that kind of service from any other engine shop)

I will post what happens after they flash the ECM
David.

[whitlock87]

Ok I have now put anther 17 hours on the boat since the ECM got flashed.
I still have the gas smell in the oil.

I will be dropping the boat off in a few weeks; I will let you know what

[Jester]

Re: Gas smell in Oil

Thats an odd one. The pan and the filter should smell the same. Thats a new one to me.
The oil should, somewhat smell like gas because of the combustion cycle. Im no expert on this thats for sure. Lee would be the man to know.

I would imagine a bad ring would smoke because of the oil reaching the top of the piston and being ignited. Then again, the water from the engine being mixed with the exhaust could reduce the amout of smoke. Does the boat leave a heavy oily/gas residue while idling in the water?

If an injector was stuck, it should run like crap at idle.

Hows the engine run through the entire RPM range?

[whitlock87]

The engine runs fine!
It idles smooth and quit.
I do not notice any smoke or oil.
The oil level is not going down, if anything it moved up a hair.
The oil is not black; it’s a nice caramel color (17 hours on it)

The boat does not have any problem reaching 50 (it can do this in just a few seconds with 6 people on board.)
I am getting about 5 gallons per hour.

The smell is quit strong. And at last oil change the oil was very thin. (I run straight 30)

I have an appointment with Tige on the 12th next month.

David