Bmw Oil Loss

[top_driver]

Hi just trying to figure out what the causes of oil loss over a litre missing after 3 weeks of topping up. No leaking the engine hasn't a wet patch anywhere at all and no smoking from exhaust. It like it just vanishing but the only thought I have is maybe the ccv oil seperator valve

[bhg481]

How many miles?

[mxyzptlk]

I had an old banger once which lost oil through a hairline crack in the sump. It was fine while the engine was cold and no drips, but when the engine was warmed up and the oil thinned a little, it oozed out.
Don't know if modern oils are subject to similar occurrence.

[top_driver]

108k

[top_driver]

Ye I guess that could be possible. Was yourself in the seal or the metal itself

[mxyzptlk]

it was a crack in the sump wall, not the seal

[bhg481]

Sorry, what I meant was how many miles did you travel in the 3 weeks, not since new.

[top_driver]

Aprox 600 miles

[top_driver]

I don't think the sump is a problem on myne there no a stain under engine

[bhg481]

Could it be getting into the cooling system via a wonky cylinder head gasket? You might expect some foam inside the oil filler cap if so. Fuel consumption and performance normal?

[top_driver]

fuel consumption is very good. in town not so much. as to be expected. i will be looking at coolant later but i hope and don't think it the head gasket

[top_driver]

one thing i did notice was excess oil in intake manifold like the texture of dirt which also made me think oil separator valve

[MantaRay]

Well, if the engine isn't smoking or has a pool of oil underneath it, and the coolant system looks clean, I don't think I would worry about it.

[top_driver]

Well if you ignore something like that and you are half way accross the country with no money with you the light goes on you have a choice to make stay there or blow your engine going home. So anything to do with oil when it substantial losses should always be taken seriously the same as coolant levels

[tonyav]

See what Scotty has to say.

https://www.youtube.com/watch?v=vZe0BOhjWVk

[DTCwordfan]

what grade oil are you using? If it's a 5W30, it could well be a Mobil product originally and at 108k miles, it may well be too thin and is either vapourising out or 'seeping' (wrong word) by similar vaporisation out of your sump seal. Check how brittle that is...... Personally I would switch to a heavier oil such as 15W30, 20W30 as with our climate, the 5W is frankly wasted, not unless you are driving to northern Scandinavia or up Alpine mountains this winter.

[tonyav]

Agree with DT on that, the oil is most likely to thin ( due to mileage and general engine wear ). How many miles have you put on it since you've owned it ?.

[top_driver]

oh forgot to mention im from rep of ireland. yes im using 5w30 never had oil problem with any previous bmw. but i had on the ramp and not a sign of oil. the engine is in amazing shape

[tonyav]

You don't know what is going on inside your engine though, top_driver !.

[top_driver]

well not fully. but engine sounds tell you a lot, especially when a car is cold, in my opinion it is the ccv but my biggest problem is rare access to a ramp

[DTCwordfan]

Just move to a more viscous oil....Mobil uses poly-alpha olefins in its chemistry and this is a thin oil when compared to a HVI baseoil from Shell, Castrol and the others.