fuel found in oil.

Topic: fuel found in oil. (Read 2125 times) previous topic - next topic

fuel found in oil.

April 24, 2005, 04:06:31 PM

What could cause gas to get into my oil? I checked my oil dipstick the other day, and it smelled like gas. Im thinking that is why it's backfiring because there is gas in the oil.

Re: fuel found in oil.

Reply #1 – April 24, 2005, 04:44:57 PM

How much gas are we talkin and when was the last time you did an oil change?

Re: fuel found in oil.

Reply #2 – April 24, 2005, 05:11:08 PM

well im not sure how much gas there is in it, but you can deffinately smell the gas in the oil. Last time I did an oil change was not to long ago maybe about 3 months ago, but the car has been sitting in the garage for a while. I just changed the oil because I put new valve covers on.

Re: fuel found in oil.

Reply #3 – April 24, 2005, 05:40:46 PM

Your running way rich man,happened to me in my old cougar when my carb was screwed up.
Sounds like your ect or o2 sensor could be screwed up.

Re: fuel found in oil.

Reply #4 – April 25, 2005, 03:14:50 PM

Whats the ect. Thanks for the info.

Re: fuel found in oil.

Reply #5 – April 25, 2005, 05:24:20 PM

is it gas or smells like gas, meaning is it real thing also? Probably just running rich, but oculd be bad rings (worst case) do a compression check to be sure

Re: fuel found in oil.

Reply #6 – April 25, 2005, 06:32:57 PM

well first off change the oil.
The pull the plugs and see how they are.
If your running rich then they will be as black as can be,
If there all carboned up then u might have a few that are not firing and that could be how fuel is getting in the oil.

If car has sat then maybe u have a ring that is gummed up and not sealing.
There are alot things that can come into play.

So start looking at the easy free things.

Re: fuel found in oil.

Reply #7 – April 25, 2005, 08:02:21 PM

I would take this opportunity to run a can of SeaFoam through the PCV system. suck it in through th PCV, let it sit overnight, then creep out EARLY in the morning (Don't want the neighbors to see the smoke show!) beat the piss out of it, then take it home, change the oil and plugs then see what's up. Change the O2 while you're at it!

Re: fuel found in oil.

Reply #8 – April 25, 2005, 08:53:06 PM

ECT= engine coolant temp sensor.

Re: fuel found in oil.

Reply #9 – April 26, 2005, 12:34:01 PM

ECT,, or ACT or what ever,, its the other coolant temp sensor with two wires. The single wire temp switch reports actual fluid temp to the dash.

typical resistance would be approx 55k ohms with the engine cold and the weather provides about 65degs outside.

the resistance decreases as your engine warms up and from that point, the eec regulates fuel/air info using the TPS ref voltage as the boss.

your gonna be looking for a ****drastic**** decrease in the sensors resistance well after the t-stat has opened. expect to read about 1.5k -2k ohms with a fully warm engine.

check to make sure your pvc sucks your finger right up and if it does,, its probably ok. If your engine rpm responds by your finger blocking off air,, expect to hear the engine r's drop a little. This also helps to determine any major vac leaks.

Id hate to think rings but is an option so nevermind what the book calls out on compression. Just make sure all the pistons measure within 5 to 10 pounds of eachother. In my opinion,, anything lower that 120psi is or is on the way to being .

Re: fuel found in oil.

Reply #10 – April 26, 2005, 12:38:50 PM

Quote from: jcassity

In my opinion,, anything lower that 120psi is or is on the way to being .

If i made fun of your car, I would have been alittle more nice.

Re: fuel found in oil.

Reply #11 – April 26, 2005, 12:44:00 PM

How is he making fun of the car?

I have a bad set of rings on the #2 cylinder of my '88's 5.0.. I would have no problem describing the situation as "".

In fact, my actual description might often be a little too colorful for this forum, depending on my mood at the time.

Re: fuel found in oil.

Reply #12 – April 26, 2005, 12:57:01 PM

he's just joking bird351,, aint no way someone could be serious like that for a "nothing meant" warning type comment.

Re: fuel found in oil.

Reply #13 – April 27, 2005, 01:42:02 PM

Oh yea, sorry for asking so many questions, but I don't know much about this stuff thats why im here asking off, Also I really appreicate all the help everyones posted. I was wondering also, if the car was off, and if I was pressing on the gas pedal, would that by any chance get fuel into the oil maybe? Im just wondering because im trying to problem solve from what i remember I did. Thanks guys.

Re: fuel found in oil.

Reply #14 – April 29, 2005, 10:37:40 AM

no,, with the car off,,,,,,,,,,, there is no electricity to the injectors or to the throttle position sensor. You will not flood the car like you might think would happen on a carb type engine. There is no pump up in the CFI or injection system so that theory is out.

when you turn the key forward you still cant flood the car out because the car is not running so the computer is not going to let this happen.

things to check

pvc vac suction
O2 sensors carbon build up
Coolant temp unit (not the single wire one which has two or three names depending on year and model car/engine)
compression is really low
compression ring end gap is too large and rings are not staggered properly
fuel presure reg problem(do you have good vac presure to this hose? you have an 87 302 right?)
injector o-ring (s) leaking
(on a cfi, this will cause fuel to dribble directly to the intake, on the multiport, the fuel will dribble on the outside of the engine and might cause a cylinder to run lean which will tell the eec to richen up the fuel)
Bad spark plug gap like not gaped wide enough
overall tune up needed
air filter dirty
coolant temp unit (not the single wire one)

you could install a 1500 - 2000 ohm resistor in place of the coolant temp sensor and run it like that for a few weeks to simulate a fully warm engine. Id probably unhook the temp sensor because the total resistance might end up being too low for the eec.