easy

It does sound like the shimming is wrong. It sounds like sometimes when the start cylinder goes out, the teeth are not always catching and thus you get the screech/grind. And, if you park it with everything in the right place/ get lucky, those teeth catch, and it rolls the engine and starts. If you replaced the starter yourself, pull it back out and when you install it, make sure you adjust it so the teeth all match up. If you didn't do it, take it back to where you had it done and have them check and adjust it. From the sounds of things, it isn't a belt because it's not even rolling the motor when you get the sound, and, it's not a problem with getting power to the starter because it either goes up and starts it or grinds it every time, thus, there is power there. I would geuss it just needs to be adjusted so that the teeth on the starter cylinder it's self, and on the gear that turns the crank just need to match up better.

my 2 cents

Sandhonda

Try checking your timing belt tensioner pulley. Also, as previously mentioned, belts and pulleys can make strange sounds when they're wet.

Samantha Knight

Did you find out what the problem is? Having the same exact issue with my 95 accord(squeals like it's already started every time I crank it), replaced the starter twice, tightened all belts, and noise got a bit quieter but still there... I know it's a long shot since this was posted year's ago but not having luck elsewhere 😕