A couple of weeks ago I was checking the oil on my truck when I noticed it was way to high. I rechecked it just to make sure and it smelled like gas. I drained the whole thing and the oil reeked like gas and it was the consistency of water it was so thin. The only two ways that I can think of for gas to get into the oil pan is through the fuel pump lifter rod and the carb, so I tore apart the fuel pump and everything seems fine. The engine still runs fine so I dont think it could be through the carb, but I did just rebuild it and I could have missed something. I put fresh oil in it but it seems to be coming up again. What else could possible be causing this? It runs fine but the oil is rising pretty fast. Any ideas would be greatly appreciated.

 

What kind of engine is it ?

If the Fuel Pump checks out the only other way gas could get into the crankcase is if the intake is leaking into the valley. But that's a heck of leak if it raises your oil level. I've seen gas explosions in crankcases. Blows every oil sealing gasket right out of the block.

 

Floats sticking - check valve sticking

If it wasn't doing it before you rebuilt the carb, then your problem has a 99% chance of being the carb.

 

is it a flatty ??? mine ran way rich ? to much pressure and i had to obviously do some adjusting on the carb { it's been my experience now / learning curve these flatty's run rich no matter what } and had to put a fuel pressure regulator on it and got it down to 2.5 pounds and no more problems like you're having . if she happens to flood out well time for an oil chang . and i dont have any leaking gaskets i can detect . cheked the intake as suggested by spraying starting fluid along it . my flatty has a LOT of miles on her so she's a lil' loose to explaining how it might be getting by some times when its flooded out .

 

I personally would check the fuel pump again.

 

Agree; It wouldn't run worth a darn if that much fuel was dumping from the carb.

 

I agree also. Look for a hole or tear in the pump diaphragm.

 

I have to vote for the fuel pump diaphram...... IMHO pretty much the only place to introduce that much fuel to the oil system and still have the engine run.
Hopefully the gas-thinned oil didn't damage the bearings...they do not really take well to a lot of gas......................

 

Another possibility just for grins.... If you have an electric pump or a friend that has one laying around, some wire, alligator clips and some spare hose. Stick it in there and do a "leak-down test". Maybe you'll be able to hear/see it. (Stethoscope ? Screwdriver ?)

 

Don't discount the carb float seal. My holley dual line had a float valve stick open and it filled one of my cylinders completely. The starter would not turn it over. If your rings are loose I could see how it could fill the crankcase with gas.

Good luck
ditz

 

It is a dead stock 239 flathead by the way. The reason i am so baffled is becuase i went through the fuel pump and checked for tears in the diaphram but didn't find any. Just to make sure i actually put in a different diaphram that also looked good but it continued to leak. I also thought that the fuel might be leaking past the rings but it never acts flooded and it turns over fine. It starts right up and never stumbles of hesitates while its running. So is it possible for it to be leaking past the rings while its sitting and still start fine? The other thing i did is i opened up the top of the carb after it had sat for a while to see if the fuel reservoir was empty, but there was just the right amount of fuel. This means it cant be leaking out of the carb while it is sitting right?

 

Get a new fuel pump. It's dumping gas with every stroke. Flatheads are known for it.

The power valve in the carb can dump some gas in the crankcase, but only when the engine stops running.