Engine failure

Based on this info, I don't think you have a way to prove that the service facility did anything wrong. It has been months and thousands of miles since you had the work done and if they did something wrong, it more then likely would have failed quicker. However, that is just stating you will have a hard time proving it because of this, it doesn't mean for sure they didn't put too little oil in it.

However, the fact that there is low oil and it is dark in color may just mean that you have had excessive blow by or other piston ring issues. Oil will get dark in a couple thousand miles and that by itself is not an issue. It could have been burning oil and if it was then that would explain why it was low with no leaks.

The only thing that I am concerned with is when you say the oil was watery. Was it water in the oil or just thin? If there was water in the oil it would look more like chocolate milk and not black. If he drained it when it was hot then that is why it was thin and drained like water. When oil is cold it is thicker.

To answer your larger question, I think your engine just failed. Sometimes these things happen. The mechanic should be able to do a little more inspection and determine why it happened. He needs to run a compression check and look in the cylinders for scoring. That will give us more info but will not change the needed repair.

As for if your insurance will cover this, that is something you will need to call them for and have them review your policy. Some do and some do not.

Let me know if you have questions. Thanks

You are welcome. That is odd about the oil. I am not sure why that would appear watery but the only thing I would suggest is compare it to a new bottle of oil of the same weight. Maybe the didn't put synthetic in it like they said but a thinner oil instead. Clearly that is a guess but it would explain that portion of it.

Please let us know if you have more questions on this. Thanks