Hey, TDB; welcome!
Oil was probably a contributing factor. What ever compacted dust was in there has likely turned to gundge.
You need to flush it through/out. My first choice, before the oil was added, would have been Mineral spirits (paint thinner) but now I'd switch to Isopropyl alcohol (Rubbing Alcohol) and a lot of it!
Taking it apart is really the most certain way of doing it properly...call Bosch Customer Service. They're very helpful.
https://www.manualslib.com/manual/476013/Bosch-1613evs.html?page=8#manual
Oil was probably a contributing factor. What ever compacted dust was in there has likely turned to gundge.
You need to flush it through/out. My first choice, before the oil was added, would have been Mineral spirits (paint thinner) but now I'd switch to Isopropyl alcohol (Rubbing Alcohol) and a lot of it!
Taking it apart is really the most certain way of doing it properly...call Bosch Customer Service. They're very helpful.
https://www.manualslib.com/manual/476013/Bosch-1613evs.html?page=8#manual