Oil coming up through carb?

[MountainManMyke]

Hey guys, this never happened to me so it may be lacking detail. My friend told me that his crestliner with omc i/o had been sitting in his yard for some years uncovered. He took the carb off to get it cleaned by a mechanic. Took the boat out for a spin and it was running okay until he had no power, and oil coming through the carb. It wouldnt matter if he went full throttle, it would just bogg and not go anywhere so he had to go home with his kicker motor. You think this motor is toast? I would imagine if it was exposed to the elements that it must have gotten god knows what in those cylinder and motor but what would cause the oil to come through the carb? I didn't do a compression test on it or anything but I just wanna know what you guys figure. Thanks

 

[infideltarget]

Re: Oil coming up through carb?

There are only a couple of ways oil can get into the intake tract, to come back thru the carb. The most obvious is extreme blow-by from bad rings, or extreme crankcase pressurization from a bad PCV system. The other way is from a bad intake manifold or head gasket, or a broken head or intake manifold. There is oil in the lifter valley under the intake manifold, and if the manifold itself is broken or cracked underneath, it could theretically suck oil up into the carb. Broken heads or bad gaskets can let things leak into places they shouldnt be going. A compression test is a logical starting point, but may not reveal a bad oil scraper ring. The least expensive culprit is the clogged PCV system.

I think I have covered all the avenues here, but it is late where I am, and I may have missed something. This will at least get you started tho.

 

[Joshua Nichols]

Re: Oil coming up through carb?

Yuck.. Bet that was a mess.. I would say siting in the weather for a long time... My vote is blow by..
Why had it been a yard ornament for so long? Bet it's cause of a internal engine problem... Do some test... compression... leak down.. That might shed some light on problems... Was it just oil or water and oil?????? light brown color??? like starbucks mocha???

 

[infideltarget]

Re: Oil coming up through carb?

I too am Still leaning toward bad rings and bad valve sealing. Sounds more and more like a rebuild is in order. You will prolly find more issues with it once it comes apart.

 

[infideltarget]

Re: Oil coming up through carb?

Yuck.. ... Was it just oil or water and oil?????? light brown color??? like starbucks mocha???

"Like...I dont know what its problem is...okay? It has this...like...stuff coming out of the thingy on top and stuff. I don't know what it is...okay? It looks like...like...a Starbucks Mocha. Like...you know...when the little guy back there...like puts too much of that stuff in it...and it is like...creamy and stuff?"

 

[MountainManMyke]

Re: Oil coming up through carb?

The reason it was sitting so long was because the stern drive needed a rebuild and he didn't have time to work on it. He ended up getting a rebuilt unit and installed it. Now the motor is toast lol. I am going to pull the motor for him in the next few months and probably tear it down and do a close inspection. Either was I think some new parts will have to be ordered. lol

 

[Split Shot]

Re: Oil coming up through carb?

"Like...I dont know what its problem is...okay? It has this...like...stuff coming out of the thingy on top and stuff. I don't know what it is...okay? It looks like...like...a Starbucks Mocha. Like...you know...when the little guy back there...like puts too much of that stuff in it...and it is like...creamy and stuff?"

??????????

 

[infideltarget]

Re: Oil coming up through carb?

??????????

Poking fun @ Josh and his reference to the oil looking like a Starbucks Mocha. Not "milky oil", not "frothy oil", etc...but a very specific reference to a very specific beverage typically consumed by teenage girls, at a very specific place. Like, okay? You like...understand, and stuff, now?

 

[Joshua Nichols]

Re: Oil coming up through carb?

It kinda does look like it... How about a Wendy's frosty?.. Bet that would LIKE be good dessert in the desert....

 

[infideltarget]

Re: Oil coming up through carb?

It kinda does look like it... How about a Wendy's frosty?.. Bet that would LIKE be good dessert in the desert....

mmmmmmm......frosty.........

Hey...no kidding, you can put a tub of cool whip, 1/2 gallon of chocolate milk, and 1 can of eagle brand condensed milk together in your ice cream maker...and it will come out EXACTLY like a frosty! mmmmmm....frosty.......