Raj Morar

I filled half litre automatic transmission oil into the engine oil filler on my W211 E90. Must I do a new oil and filter change or will it just burn out. Thanks

pinebaron

Drain complete engine oil, replace filter, then refill with fresh engine oil; I would not do it any other way.

2.7Tallroader

I agree with the reply above. The two oils have very different characteristics. Engine oil lubricates and reduces friction, while transmission oil lubricates and aids the friction materials.

If you haven't started the car after you've accidentally put in ATF, then drain, it, replace the filter before you start the car. Conservatively, I would have a short oil change interval, after which you can resume the normal intervals you use.

Raj Morar

Thank you for your assistance. I did start and run the vehicle and only realised my mistake by chance while reading other posts on the forum.

Glyn M Ruck

From the oil industry. Chaps above are correct. You must change oil & filter.

homeofstone

Do the oil filter change before driving any more miles. do it ASAP