Went through mud puddle and car died 100 yards
tried to crank, starter would spin but wouldn't
Thought solenoid was up,not sure
If you can hear the starter working, but it does not engage into the flywheel ring gear, then it could be the starter drive, or the solenoid plunger not pulling back to engage the starter drive. Never the less there is a problem with the starter.
So how would I fix without changing starter
You could try and take a hammer to it, and tap on the starter to see if it is just hung up. More than likely down the road you will need to replace the starter.
I agree with Rowefast. It's more than likely the starter Bendix. Some you can just replace the Bendix, and others you can't simply because they don't sell the part. They want you to purchase the complete starter unfortunately.
Looking for a Used Grand Prix in your area?
CarGurus has 73 nationwide Grand Prix listings starting at $2,495.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts
Related Models For Sale
Used Cars For Sale