Could this be caused by a bad crank pulley?

[tay97gst]

Last night, I went to start my car and heard a terrible knocking noise. I immediately shut it off and opened the hood and saw that my alternator belt was completely off the alternator bearing. However, the belt was still tight. My instincts point to the crank pulley as the culprit because I have already replaced my alternator and belt because of squealing, and yet it still chirps, a common symptom of a bad crank pulley. I have visually inspected the crank pulley but it really doesn't look that bad. Could a bad crank pulley force the alternator belt off of the alternator bearing while still being tight?

 

[Cdc1221]

Can you move the crank pulley? As in any back and forth wobble?

 

[tay97gst]

Can you move the crank pulley? As in any back and forth wobble?

I can't check right now, it's too dark, but that's something i'll check and report back. I really only did a visual inspection when i was down there replacing the belts a few months ago.

 

[1Gina2G]

you sure your both your water pump pulleys are on right, do they wobble while moving? Do the belts pop off right away or randomly?

 

[tay97gst]

you sure your both your water pump pulleys are on right, do they wobble while moving? Do the belts pop off right away or randomly?

I havent felt any of them wobble, and it was just randomly. My new alternator/belt has been on since november, it just randomly came off last night when I first started my car.

 

[pauleyman]

You are likely guessing correctly.

 

[DSM1G90]

Have you removed the two belts and checked the HB pulley by grabbing the outer part and see if anything is loose ?

Only way you're really going to find out.

 

[tay97gst]

Have you removed the two belts and checked the HB pulley by grabbing the outer part and see if anything is loose ?

Only way you're really going to find out.

I will give the HB a better look this weekend. But honestly, is there anything else that could cause these symptoms?

 

[Cdc1221]

A bent alternator shaft could.

 

[tay97gst]

A bent alternator shaft could.

Is that part of the alternator itself?

 

[PoorMan'sDSM]

I think this happened to me a couple years ago. Sounds awful but the car still runs? I had to drive mine about a 1/4 mile back to my house. I had day light tho so when I looked it was very easy to see that it was jacked up. My harmonic balancer/ crank pulley was very easy to replace. Jack up the car, remove driver side front wheel, I seem to remember the pulley itself being held on by four bolts. Maybe 10mm, but not sure. I got my replacement at Autozone. It's a Dorman with a lifetime warranty. Has worked fine for a couple years now.

 

[tay97gst]

Quick questions regarding the crank pulley. I know it can cause the belt to squeal, but does it cause the belt to squeal literally AT the crank pulley's location?