Hi guys. long time since the last time I was arround here. Last night, the bonnie started making a noice in the engine, specially in idle. No shaking nor fisfireing. My dad and I removed the */C belt but the noise continued. It made a clank noise when the engine starts and then sounds like a loose piece of metal hitting something. Tonight, we put the belt back on, thinking the SC was OK, but the sound worsened. We removed it again and the sound almost went away, altough it was still there. And the sound comes from the top-front of the engine (right side of the car). Right now the car has the SC belt removed, because my mom needs the car to go to work tomorow, and my dad is going to call the technician to se what can he do. But I wanted to ask the experts first.

Any idea? The car have 76k or 78k miles (cant remember). Is it expensive to repair? Can be anithing else? It is the same of the Grand Prix? I thanks in advance for the help.

It makes sense that it would be the coupler, but that doesn't explain the noise it makes with the belt off. If it is the coupler, then it would actually be just fine to drive with the belt on, it will just be noisy. The coupler is fairly easy to replace and I think a new one costs like $79 or so from ZZP. (GM doesn't sell one IIRC)

Shawn

With the SC belt off, the SC will make absolutely no noise at all because it is not moving. I suspect a bad balancer pulley (mine sounded higher on the engine, just because the noise carries through the engine) or maybe the tensioner.

ZZP couplers are $36. FYI

With the belt off the */C take and turn the pulley by hand and see if it'* making the same noise......Otherwise if it still makes the noise with the belt off and the car running I am with Jwiloff....check your harmonic balancer (crank pulley)

We thought the same thing. Thats the reason we removed the SC belt. But the noise continued. It is really loud to be the tensioner. We thought maybe something loose inside the SC. Maybe a bad bearing, shaft or something. Our knowledge about these cars isn't very extense. But anyway, your opinions give me more hope than I thought

PD. What exactly is the coupler?

The coupler mates the drive shaft with the rotor shaft. It kinda looks like a hockey puck with 6 holes. The drive shaft has three prongs on the end, as does the aligning rotor shaft.

A broken balancer is not supposed to make vibrate the engine? At least that'* how I knew the one on my mustang was shot. The whole car was vibrating. .With the bonneville, the sound is kind of inconsistent. Some times if you turn on the A/C it stops for a moment, sometimes it doesn't. With the SC belt it was loud and continuous, but without it is less continous. I'ts really an enigma.
But anyway, I'll keep you posted about anything that happens. Thanks.

Hrmmmm Well seeing how having the A/C on or off or the */C belt on or off is imposing different loads on the engine, if it was the balancer I would definantly expect the symptoms to be different in each case.

But a balancer should make your car vibrate if it'* way bad....seeing how that'* what keep your crankshaft in balance. Your'* could just be in the begining stages?

Hey guys. UPDATE:

I arrived to my home today, so I haven't checked the car yet, but my dad tooked it to the shop and the guy told him that in fact it wasn't the supercharger. He inspected the balancer, the water pump and the tensioners and they all looked OK. He thinks that it could be the timing chain tensioner or something related, as the sound depends on the load on the engine. He told us to keep checking if we found the problem, but if not, he is going to take it on monday.

Does it sound like something reasonable? Any options?