motor oil

[top_driver]

hi, i was just curious to know, i put some 5w40 into my car, it is the recommended for it, but, i am not sure if the owners before put in the same or put in the cheaper 10w40, what would it do having about a ltr of the 5w4 out of 6.5 of other, would it do any harm, or?

[AlBags]

Not on a BMW E36 323 you won't, no.
Many, incl GSF parts would probably supply you with 10w40 for that engine anyway.

[top_driver]

its an e46 323, or would it be the same as an e36

[AlBags]

Oops .. sorry .. yes .. similar engine.

BMW are 'keen' that 5w40 is used .. although on higher mileages (ie over 100K miles, one would use a 10w40)
You certainly will not do any harm topping up with some 10w40, but if you are below 100K miles, I would stick to 5w40 and get it from GSF Parts or the like.

[top_driver]

im just worried because i might have the two grades mixed, but i am looking to get an oil change, yes the car is over the 100k mark

[AlBags]

Then I would personally stick to 10w40 from GSF or BMW.

[top_driver]

ok, i dont know who gsf are, but i will be getting an oil change anyway, and using engine flush to clear any sludge

[AlBags]

If I were you .. and the engine is otherwise fine .. I would skip the flush!
It can do more harm than good with stuff migrating around the engine.

Just change oil and filter every 10K miles max.

[top_driver]

ok, it just i already have flush from the last car i didn't get to use it on, what could it do