fuel in the oil

[paxmaster2000]

i am about to have my 97 318ti delievered. i bought it with this problem but it is really good shape.
the problem is that the oil stick shows gas mixing with the oil. when it starts it smells like gas. the ol is real runny. i was told that the oil should be drained and the cause is the cat. i then read that it could be one or more injectors leaking.
this car is so clean i couldnt pass it up. no check engine ever so it was either removed or dead.

[ti cali ed]

About the only way to get gas in the oil is if the rings are shot. In which case you need a complete rebuild. I'd do a compression test to start with. This is the simplist test and cheapest. You basicly remove the spark plugs hook the gauge in to the plug hole and turn the engine over. Chances are one is going to read much lowwer than the rest. Some people prefer to do what they call a leakdown test. this is where you pump air into the plug hole and see if it can hold the air. The advantage of this is you are also checking the valves. As far as injectors leaking goes, I've only ever seen this happen once and the car wouldn't run it flooded itself as soon as the key was turned on. If the car runs the check engine light should be on if the injectors leaked as it would throw off the o2 sensor readings. The cat has nothing to do with this problem however if the car is sending unburnt gas out the tail pipe it will quickly be ruined by the fuel. How's the car run? I'm assuming it's weak or has a miss.

[paxmaster2000]

Well i have found that i had blown head gasket and the thermostat
Was bad. This caused fuel to be dumped. Should have everything done soon

[ti cali ed]

Not to discourage you by any means. But I believe the thermostat on these are designed to stick open if they stick. This would cause the car to take forever to heat up. I like this better than on my vintage mustang that a bad thermostat means it overheats. This would have nothing to do with fuel being dumped. Most times if you lose a head gasket you either leak antifreeze into the cyclinder and steam comes out the tail pipe making your car look like a fog machine. Or you have a mixing of your oil in the antifreeze or antifreeze in the oil. Maybe this is what you were talking about with your oil. I describe it as looking like a chocolate milk shake. Would the smell not be gas but antifreeze? Antifreeze has a sweet smell to it.

[savannah996]

Originally Posted by ti cali ed

About the only way to get gas in the oil is if the rings are shot. In which case you need a complete rebuild. I'd do a compression test to start with. This is the simplist test and cheapest. You basicly remove the spark plugs hook the gauge in to the plug hole and turn the engine over. Chances are one is going to read much lowwer than the rest. Some people prefer to do what they call a leakdown test. this is where you pump air into the plug hole and see if it can hold the air. The advantage of this is you are also checking the valves. As far as injectors leaking goes, I've only ever seen this happen once and the car wouldn't run it flooded itself as soon as the key was turned on. If the car runs the check engine light should be on if the injectors leaked as it would throw off the o2 sensor readings. The cat has nothing to do with this problem however if the car is sending unburnt gas out the tail pipe it will quickly be ruined by the fuel. How's the car run? I'm assuming it's weak or has a miss.

not true, leaking injectors can get fuel in the oil.

[pdxmotorhead]

Thermostat stuck open will make engine run rich, and contaminate the oil...
2x worse if the injectors are bleeding (Not closing all the way) and you drive in city traffic.

Dave

[active20082009]

hi there, i was wondering if anyone can help me figure out whats the problem on my 1996 318 Ti with 180k on it it runs and drives perfect , no smoke or rough idle but lately i discovered a yellow/green small dotes on my oil dipstick on the end (bottom) of it you can barely see it , i do travel short distance to work every day (5 miles each way ) i did change the ccv (oil separator ,or pvc valve ) last week , but the yellow green crap is still there . please help

[spidertri]

Drive it for 30 - 60mins and see if the yellow stuff is still there. I used to get that when I had a 2.5 mile commute each day.

[JustinH]

ti cali ed has hit the nail on the head on this issue. Your rings are likely shot. Head gasket/thermostat is not why fuel is in your oil. That just makes no sense mechanically.

[paxmaster2000]

If the the thermostat is bad and the computer doesnt think
That the engine is getting hot from the readings of the
O2 sensor doesnt it tell the fuel to dump until
It is warm?
When i removed the valve cover there was a hint oof
Milk color . The head removed there was a crease between
The second and third piston. They were both clean and the others
Were still black.
Well hopefully i will have the car running this weekend.
I believe the fuel smell was from the car being started and injectors
Dumping fuel trying to keep it running

[ti cali ed]

There is a temp sensor that tells the computer if the engine is warm or not. If it is cold it will enrich the fuel mix, like puting on a choke on a carb, untill the engine warms up. On a bmw if the thermostat fails it fails open and it will take the car slightly longer to warm up, but it still will warm up without issue. The milky oil is yes a mix of oil and antifreeze. And is a sign of a bad head gasket or head or block. Run a staight edge over the head and block and check for warpage. If everything checks out ok put the head gasket in it and see how she runs. This however does not mean the rings are not bad or weak. Weather the injectors are 'dumping' the correct amount of fuel or fuel by the tanker load into the cylinder if the fuel is leaking past the pistons into the oil the rings are bad end of story. Now will a engine run with bad rings? Many times yes. Will it have the same power as a fresh engine, no. Will it smoke? Maybe, many engines with failing rings will blow blue smoke from the tail pipe when started. Some don't. Some let you know by creating large amounts of crank case blow by or pushing oil into the intake.