gas in the oil

mackamitsu · #1 12-14-2005, 09:54 AM

Hi guys,

I'm stumped, I am getting gas in the oil, I replaced the intake gasket, and the head gaskets. I torqued them down, ran them and checked the torque after an hour of idling. It's a 307, any ideas????

silicon212 · #2 12-14-2005, 10:37 AM

Replace your fuel pump.

bobss396 · #3 12-14-2005, 11:43 AM

Sounds like too much fuel to me. Look for a stuck carb float or leaky float bowl plug.

mackamitsu · #4 12-14-2005, 12:16 PM

ok I'm checking those things tonight, thanks for helping me unfreeze the brain

1986Z28 · #5 12-14-2005, 01:58 PM

i was getting oil in my old caaprice with the 307, but it had really bad rings

PeteA216 · #6 12-14-2005, 05:42 PM

While we're on the subject of oil, and things that shouldn't be mixed in with it, what does it mean when you get a tan colored foam on the oil dipstick right after shutting off the engine?

mackamitsu · #7 12-14-2005, 05:55 PM

Quote:

Originally Posted by PeteA216

While we're on the subject of oil, and things that shouldn't be mixed in with it, what does it mean when you get a tan colored foam on the oil dipstick right after shutting off the engine?

what does it smell like?? mine was a light tannish colour and smelt of gas, and it was the fuel pump. I am going to pull the carb on Saturday though, seeing this beasty was sitting for a season.

silicon212 · #8 12-14-2005, 07:03 PM

light tannish oil is presence of coolant in the oil - not good - poss blown head gasket, warped heads or cracked head/block. Most likely head gasket and warped head - has it overheated lately?

1986Z28 · #9 12-14-2005, 08:45 PM

coolant in oil is bad, but he says he smelt gas

silicon212 · #10 12-14-2005, 10:02 PM

If the engine has high mileage on it, then blowby can cause the fuelish smell - tan oil is ALWAYS water and/or coolant. Gasoline in oil will thin the oil, but not discolor it. Oil with a lot of gasoline in it will have a solvent-like quality to it - hard to explain, you'd know it when you saw it. Aside from rust issues with water and the lack of lubricity it poses, coolant is acidic and will take out the bearings if you wait too long.

Aside from thinning the viscosity and possibly causing premature breakdown (which in itself is bad news), a little gasoline in the oil will not pose too much of a problem, and assuming the flow can be stemmed, will evaporate from the oil.

Regarding my original comment about the fuel pump above - the mechanical fuel pump presents the largest opportunity for raw gasoline to enter the crankcase - it's happened to me. The only other way that gas can enter the crankcase in fairly large quantities would be from seriously flooding a carburetor.

bobss396 · #11 12-15-2005, 06:38 AM

I hadn't thought of the fuel pump, a good place to start. Especially if the motor has been sitting for a while. They're pretty cheap and easy to change. Once you have it out you can tell if that's the source of your gas inlet.

Bob

mackamitsu · #12 12-15-2005, 07:04 AM

Quote:

Originally Posted by bobss396

I hadn't thought of the fuel pump, a good place to start. Especially if the motor has been sitting for a while. They're pretty cheap and easy to change. Once you have it out you can tell if that's the source of your gas inlet.

Bob

Yea it was the pump

, could see where the little gasket going to the arm should have been. Changed the oil, going to let it idle today for a while, and see if we get the other issue, the old intake and head gaskets were pretty dry, the new ones aren't, so we'll see how it goes. Hopefully I can score a set of 5A heads.

PeteA216 · #13 12-15-2005, 10:25 AM

Im glad that the fuel pump was ur problem, it made a lot of sense. As to answer the questions above, my engine has 72K on it. No it hasnt overheated at all in the 3 years I've owned it. The oil doesnt have much of a smell to it, but every once in a while while driving, or after i shut off the car and get out I can small burning antifreeze, but I can't find any leaks or steam coming from under the engine compartment.

My father suggested that since my PCV valve was replaced with abreather, air isnt properly being pumped through the crank case and condensation is building up inside causing the tan color in the oil. Is that even possible?

silicon212 · #14 12-15-2005, 10:37 AM

Not generally, but there is another possibility I didn't think of earlier - if that has the factory intake on it then it's made of aluminum. These often corroded and allowed coolant into the oil. Places to look are the back of the engine where the water ports on the heads would be, as well as any obvious sign of corrosion anywhere on the intake near a water passage.

bobss396 · #15 12-15-2005, 10:37 AM

Pete, I think you should still run a PCV valve. You could be getting a condensation build up, look at your oil fill cap too. You might see a light build up on it.

I used to get an antifreeze smell on my '84 once in a while. I believe it is the heater core. I dumped in a vial of those silver crystals which stopped my coolant loss, I do get a very slight whiff now and then still.

You could still have a head gasket leak, dump in a can of Solder Seal Block Saver. Older auto parts stores carry it, you usually have to ask for it. Also pressure check your system if you have a tester, or borrow one. It should show anything like a hose, thermostat housing, heater control valve leak, also maybe the heater core.

Bob

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