does this sound like a waterpump problem or crank pulley?

[bmwisthekey]

my friend has a 97 gst, today there was a knocking , rattling sound coming from the driver side timing belt- accesory belt area., timing belt is fairly new was intact and operating normally, car runs fine, we thought bad water pump, bearings etc.. (car isnt leaking any coolant), so we took the the water pump belt off the water pump pulley and crank pulley to see if the noise went away. When we started the engine again, yes tje noise was indeed gone.

my question is could this noise of been from the crank pulley separating or being loose and since we removed the load of the water pump belt and power steering belt (waterpump is driven via the crankpulley which also spins the powersteering belt since its hooked up to the water pump pulley) from the crankshaft pulley it caused the noise to go away since the crank pulley didnt have much of a load on it, im trying to rule out that the noise is a bad water pump ### thats gonna be a crappy job to replace ( timing belt removal etc...) im gonna inspect the crank pulley tommorow i just wanted to ask if the waterpump is going bad , can it make a pretty loud knocking- rattling noise.

the water pump spins with alittle resistance -its not loose, and its not hard to spin , the lateral play in the pump pulley end is minimal. lemme know what you guys think, seems like the crankpulley separating or being wobbly would cause this weird knocking noise not the waterpump. thanx in advance, john

 

[brodiedehass]

When I bought my 1995 Talon it was making a bad knocking noise. It only ended up being the crankpulley. It was so bad I could separate the inner and outer ring. If your outer ring is really sloppy it is probably that. I don't know how a water pump could have a loud knocking noise, but anything is possible.

 

[FastYZFR6]

I am thinking crank pully as well

Later,
James

 

[bmwisthekey]

thats the weird thing, we took the belts off of the pulleys on the waterpump and the noise went away, but it could of been the crank pulley making the noise in the 1st place but now there wasnt much load on the crank pulley with the belt removed, theres only one way to find out , look at it i was just curious if anyone has ever associated a water pump going bad, by a knocking -rattling noise.

 

[Old Mitsu Tech]

Yes they can. If you grab ahold of each pulley and turn it it should turn freely with no side to side play or wobbling of any kind. If the crank pulley is for sure good, I'd look at the water pump myself as it's the second most likely culprit. Not to mention so much fun to change.

Good Luck