Belt came off, engine overheated, water in 3 cylinders

[SONIC]

The belt could use replacing but I doubt that's why it's coming off.
Turn all the pulleys by hand, they should all spin fairly freely other than the raw water pump.
In my experience it's usually either bad alignment or a pulley seizing up that causes them to jump.
Alternator is a likely suspect

[dpickett]

Thanks for all the advice. I checked all the pulleys. By an eyeball test, they all seem to be in line. I don't have a laser tool to check with. Here's a quick assessment of them all:

Two idler pulleys: spin freely with a tiny amount of wiggle
Alternator pulley: spins the best (it looks newish) and no wiggle at all
Circulation pump pulley: spins freely and has some wiggle, but not a lot
Crankshaft pulley: does not spin by hand. I'm assuming this is because it will spin when the motor is running and that's what moves the belt. No wiggle at all
Raw water pump pulley: spins with some force becacuse of the impeller. No wiggle. I took this off to check the impeller and waiting for a new one from Amazon before re-installing.

I made some videos just in case someone on here can pick up something I'm missing. Here's all but the raw water pullley. Here is the raw water pulley.

I also ordered a new belt.

Anyone see something that I'm missing that would cause the belt to jump off?

[freeheel4life]

Your video isn't showing up for me....but once you get it back together and get the belt on Id just run and put eyes on the situation and look for the wobbling pulley.

[dpickett]

Yeah, you have to hover over the words for the link to show up. I'll do that. Does the belt tend to come off where the bad pulley is?

[Aspidaso]

Thanks for all the advice. I checked all the pulleys. By an eyeball test, they all seem to be in line. I don't have a laser tool to check with. Here's a quick assessment of them all:

Two idler pulleys: spin freely with a tiny amount of wiggle
Alternator pulley: spins the best (it looks newish) and no wiggle at all
Circulation pump pulley: spins freely and has some wiggle, but not a lot
Crankshaft pulley: does not spin by hand. I'm assuming this is because it will spin when the motor is running and that's what moves the belt. No wiggle at all
Raw water pump pulley: spins with some force becacuse of the impeller. No wiggle. I took this off to check the impeller and waiting for a new one from Amazon before re-installing.

I made some videos just in case someone on here can pick up something I'm missing. Here's all but the raw water pullley. Here is the raw water pulley.

I also ordered a new belt.

Anyone see something that I'm missing that would cause the belt to jump off?

You are being to gentle pump in your video, if you still have it out put it in a vice (snug not to tight) pull on the pulley, if it comes out that is your issue. Just happened to me on labor day weekend. Do not by a new pump they make a repair kit and is pretty simple and tools are availible for free at auto parts store.

[dpickett]

I forgot to follow up. I put the new belt on (along with new plugs and impeller, although those were just needed maintenance). The engine ran fine and the belt stayed on. It ran fine all last weekend. I guess it was the belt, but I'm not really sure. Thanks for all the help.

[boatwakes]

Hey DPickett, good to hear?!!! I'm not ever convinced it was just the belt unless the belt in question was aftermarket. Keep an eye on temps and listen for changes in exhaust note and keep us posted.

[UNSTUCK]

And keep an eye on that circulation pump. There's enough wobble in the pulley that the seal will fail soon and it will start to leak. Also, looked like you had some dirt or something stuck in some of the grooves of the crank pully. That could cause the belt to jump.