| Not unusual tbh. Depends on the state of the oil that was dropped. The detergents in the new oil have got to work and started to clean the internals. Not going to harm the new oil really. Might be worth an intermediate change between services to clear it out. You could try a cleaning agents prior to dropping the oil to help next change.
Also, you'll never get all the old oil out completely at a drain. You can help things along by removing the strainer, or even taking the cooler off and giving that a drain down to. |