oil smells like gas.

[Rukus]

i dirve an 84 318i. i took my oil filler cap off while the car was running and noticed that it smelt like gas.

i understand this can be caused by bad rings, or valve seals (your main cause of blowby). OR a stuck open injector (or injectors that stay open too long) allowing fuel to go forced where its not suppsoed to go.

does anyone else have any suiggestions for me?


thanks.

 

[wood_e]

Try some injector cleaner to see if that fixes the asupposed sticking. Also try a decarbon procedure... I dunno man it sounds like you need new rings... How many miles on it?

 

[Rukus]

there is over 300,000kms on it.

i decarbonized th engine with water injection, and i threw in some injector cleaning.

i sohuld have mentioned that my valve seals are worn and need replacing.

 

[wood_e]

Ah well if all that was done then I would replace those valve seals first to see what that does. That may be the source of your problem.

 

[jnyost]

Do you have blowby?

 

[KC Ron Carter]

Hmm,

You live in a cold climate.

Unless the car is driven on a 30 minute high speed trip the smell of fuel in the crankcase would be normal.

Do not fix what is not broken.

Later,

 

[Kirby]

With that many miles on the engine, you will get gas in the oil, as KC Ron Carter said, it will be worse if you do primarily cold driving.

In this case it's VERY important to change the oil regularly 2000 - 3000 miles. The gasoline thins the oil out, reducing the viscosity, and also neutralizes the detergents and other additives more quickly - all bad things. If you really want to know what's up, you need to do cold and warm compression tests on each cylinder.

 

[bignate]

Use a higher viscoty oil (I use 20W-50) so the gas won't affect performance as much

 

[Rukus]

Yeah, me and my friend wre jsut talking about the compresson tests. He said too bad i didn't have access to one, because thats the only way to check/know stuff.

right now i Run 5w30. so next oil change what kind of oil should i try? My area of Canada isn't typically a cold as other parts of Canada, right now its been sitting at 15° C. REALLY warm for this time of year. in the winter, we only had a few days where it was REALLY cold.. most were just barely below freezing. it will get REAL warm in the summer time (this is desert area of canada) it gets upwards of 40°C some days.....



maybe a 10w40?

 

[ldzpstnr]

I am using 10w-40 right now. How cold does it get during the nights?

My bmw owners manual states that 20w-50 will work all the way down to negative 10 Celsiuos and up to 50 C. 5w-30 according to BMW will protect from negative 40 C and up to negative 5 C. Dont use 5w-30, especially in that engine with that many kilometers on it. Its not thick enough. Thicker oil I think will help cut down on your blow-by.

Later
Aaron

 

[Kirby]

Like the above post says, go with 20-50 unless the temps get too low. You should still stay on top of the oil changes.

You can pick up a cheap, shade tree quality compression gauge kit for $30 - $40 tops. That should let you know what you need to focus on. If the piston/cylinder tolerances are bad, the valve seal job is not well spent money.

 

[german-speed-demon]

One other thing to check is lok for fuel leaks. I just spent the weekend replacing my water pump, visous fan, and tore the rest of the engine apart to replace seals, onmly to find i had a small fuel leak under the intake. as the fuel evap'ed, my oil smelled like fuel as well. And it only took me 1900 bucks to realize it.