Congrats on your purchase. I have been tinkering with a 1.0 litre Micra for a couple of years now. Went to change the tires for winter and the tire guys pointed out an oil leak. It was the distributor O ring. I understand it is not unusual for this to happen on the resilient little engine. Later even the internal parts of the distributor leaked. But I just realized you must have a coil pack system. So, this does not apply to you.
There is another leak on this Micra and after eliminating the distributor, from what I can tell, it could be the main seal. And mine leaks very very slowly. Example: a day at the mall and coming back to the car and not seeing any leak. But a few days in the regular parking spot and there's a tiny bit. Many might say that if it is your main seal that you should just get by with it and not worry. Others may say that it can be addressed when you want to maintain your clutch-which is correct. The transaxle, or transmission as some call it, must be removed. The Haynes Manual (you can get a hard copy manual that was used, I guess you can say, in the old days) says that the level of difficulty for a clutch replacement is 4 out of 5 wrench symbols of difficulty { "Cluth Assemby - removal, inspection, and refitting." }. It is a tough job for me. Others may say it is not so hard on a Micra and I can see what they mean by that.
In the manual, it is called a 'crankshaft oil seal' and the one that i am refering to is the, 'Left - hand (flywheel/driveplate) oil seal'. Which is the one that you would want to replace when 'doing the clutch'. in the manual it says that the left- hand seal is 3 out of 5 wrench symbols of difficulty. Translation: it is a tough job too- at least for me and my bad back. It is listed separetely but you really should do the clutch too when doing it.
I'm just saying that I wonder if that is where your leak is coming from. It could be something as common as your oil pan drain plug not being tightened enough (but don't tighten too much) or the drain pan gasket seal.
But I'm pretty sure it is the main seal on mine that is dripping very slowly. Hope this gives some insight.
