Water pump/Fan pulley
 

SO i have a slightly serious problem that i have no idea how to diagnose... My pulley the connects to the water pump and the clutch fan is wobbly. When the car is off i can wobble it about a 1/4 inch and i know it cant be a loose bolt because when i replaced my water pump about 5-6 months ago i followed an FSM and did everything to exact spec.

I just need to know what it could be and what i would need to fix it. I'm thinking it might be the idler pulley bearing but i dont even know what that is (embarassingly, i know i should)

Thanks to anyone that could help

The pulley is a direct mechanical fit to the waterpump hub (four bolts for the pulley and four more for the fan)...properly installed there really can't be any play.

Remove the belt tension and see what's loose.

Is it the belt or the water pump pulley? The belts that drive the water pump are tensioned by the accessory it drives (either air pump or alternator). Both have a slotted mounting bracket. Loosen the bolt, move the accessory until belt is tight, hold it there while tightening bolt. It is common to have to re-tighten belts after installing new belts.
If it actually is your water pump pulley, you need a water pump.

The water pump bearing may be toast. Remove the clutch fan, and see if it still wobbles. You can turn it by hand to see if there is any play that should not be there. I once had a vibration at 4-5000 RPM that turned out to be a bad bearing in my new water pump.

@RotaryRocket: Sucks to hear that man. I think i just had a human mistake and did something wrong/out of spec. It's a Bosch pump so i doubt it was the engineering behind it.

+1 for a roasted bearing

you can't really screw up when it comes to replacing a water pump, sounds like you got a bad unit. unless you didn't tighten the bolts AND the clutch fan nuts on the pulley there's not much else it could be. double check the warranty info on the pump you bought, most come with a 1-year warranty so you might be able to replace it for free.