I've finished sketching what will be the design for an engine block and I am encountering an error when trying to extrude the sketch. I really dont want to have to re-draw this sketch from the beginning. What could be my problem?
The problem is the sketch pattern of open loops, they do not constrain end points even if they mathmatically exact.
Create the extrusion from a base closed loop and pattern as a feature.
Edit your sketch.
Right Mouse button and select Show All Constraints.
What do you see?
This is actually a simple sketch to do if you start over, about 5 minutes work.
Keep sketches simple and pattern (and mirror) features rather than pattern sketches as suggested.
You are doing wayyyyyy too much work.
In fact, this one is soooo simple I would do it over for you if you find it too hard to do over, if you attach your file here.
I recommend you start here
That sketch is way too complicated. Keep sketches as simple as possible. Great rule, start from the outside in. The outside profile would be your first sketch, but keep fillets, chamfers and patterns (arrays) out of all sketches. Those are best managed as a feature.
When i hit show all constraints, i got what looked like an electron cloud ....
Inventor has to solve all of those sketch constraints. Making complicated sketches like this will bring your computer to it's knees.
That is why everyone is suggesting to pattern features rather than sketches.