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GP 3.1 crank balancer

I took my 99 Grad Prix in to get it serviced yesterday and was told that the pulley on the crankshaft is coming off. Waiting to hear back from a mechanic that was suppose to look at it. In my initial call to him, he said this is not uncommon. Is that the case?

Any ideas what causes this? When looking down from the top, I can see the pulley and then what looks like (bad description here) a brake rotor. I say that because it has two plates of metal that appear to be separated by equally spaced pieces of metal all the way around. One mechanic I talked with on the phone said that is part of the haloffect crankshaft position sensor.

He asked me if the bolt had come out of the pulley. I went out, but am not certain what I'm feeling for. It is the 3.1 engine so I think there is suppose to be one bolt through the center. I think it is the 3.4 that has three bolts holding the pulley in place. I feel the three holes, but no bolts there and so I'm not certain if I'm correct. I can't tell that there is anything in the center of the pulley or not.

He seemed to think that it could be the crankshaft coming apart. Does this happen frequently?

Reply to
RAS
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I'm not aware of the crank pulleys walking off on those. There is ONE big bolt that goes on the front dead center of the pulley, it either broke off or walked itself out. The other 3 holes are used for a puller. The thing that looks like a brake rotor to you are shutters. They pass through the Hall Effect Sensor which is a magnet. As they pass through and leave the magnet the magnetic feild collapses and sends a voltage to the ignition modual telling it when to fire a coil.

Reply to
Bon·ne·ville

Turned out that the bolt holding the pulley in place was sheared off. In addition the balancer sleeve(?) had gone bad and the pulley was walking off which was then eating away at the belt. The mechanic showed me the rubber sleeve and how the pulley was coming off. So, $400 later, I have a new balancer, belt, and crankshaft seal in place. Would have been less expensive but for the fact the bolt was broke off.

Reply to
RAS

Yup a hardened bolt is hell to get out and I thought it would of been=20 strange for it to have walked out when its got a torque of about=20

110pounds > Turned out that the bolt holding the pulley in place was sheared off. In
Reply to
Bon·ne·ville

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