Firstly have you
. It will tell you how to check the coolant level, although if it was low the OBC would tell you?
I never checked the coolant level on my 335d but if after ascertaining what is the correct level and you do need to top it up, again you'll have to read the manual as some manufacturers would only top up with neat coolant (as Porsches are), others if bought from BMW may be pre-mixed. Bottom line is the coolant has to be mixed, or not as applicable and the coolant itself has to meet the specification stated in the manual. Sure someone on here will know off the top of their head 'cos I can't remember tbh.
The 'oil reservoir' thing is your power steering fluid reservoir.
The dipstick should be pressed 'fully home' into the tube to obtain the correct reading. The engine should be at normal running temp. and have been switched off for about 5 minutes before checking the level. Again the manual will confirm.
I asked you some time ago which part of Hull you were from but you ignored me, so sod ya.
