If you’ve done as the dealer suggested and rubbed the excess oil away, try stitching something on a scrap of fabric that you would throw away anyway, Do a good size embroidery with inexpensive thread and see what happens. If no more oil is dripping, you should be good to go. I’ve never had this happen, but I think it could be something that might, especially if the technician got interrupted while he was working and didn’t perhaps run his cloth over the area when he was finishing. However, if there is still oil dripping after you test it again, take it back and have them look at it.
I know that we sometimes get worried and rightfully so as these are expensive machines. We do need to give things a test first though before we go into panic mode. For example, yesterday I changed the thread on my Continental M7 and it made a horrible noise when I started stitching. I checked and sure enough, I’d missed the take-up lever and she wasn’t a happy machine at all. Now checking the take-up on that machine is a chore as there is NO door that opens, for my eyes that is a “probably just re-thread the machine”. I think the 15000 does a similar thing when the take-up lever is missed or pops out. My previous machines would sew on, not happily, but usually ending up in a bobbin replacement and nesting disaster and a drip to the repair man for a checkup of the bobbin race and a timing adjustment - it wasn’t fun.
Let us know how you make out.
Cheryl - Saskatoon