'96 Buick Century - Ghost In The Machine

[ShaunMac]

Hey, Y'all ...

I purchased this '96 Buick Century w/46,565 miles back in October of last year. I am pleased with the engine, which runs like a top.

But in the middle of January, there started an intermittent problem that is starting to drive me insane.

When I am driving, there is sometimes a sudden, loud sound coming from the center of the firewall, or possibly inbetween the firewall and the dashboard. The sound is like an "impact" sound, like a pneumatic tool would make, or possibly a grinding sound, something rotary, as if a gear were loose, or maybe a bad bearing were grinding in some part inside this area. It is a difficult sound to describe, but when it occurs, it's very audible, and it sounds like an impact sound, like a lifter, or loose rod, but also rotary, like a loose gear or a bad bearing. There is no change in engine performance when this occurs. And the locvation of the sound is back, away from the engine, either at or behind the firewall.

If I let off the gas, and let the speed come down, the sound dissipates. But then it - sometimes - starts back up if I come back to speed, sometimes right away, other times at higher speeds than when it started.

This is interesting - sometimes if I continue when the sound starts, or even add power, whatever the problem is will get louder, but then seems to snap into place after awhile with a loud whack, and I can continue for awhile. Sometimes it comes back, other times I can continue without further incident.

This sound has -NEVER - performed for anyone else as of yet! My brother, who is a truck driver, often having to deal with mechanical things, tested the car without incident the day after I thought that whatever it is was going to completely fail! I had it at the dealer just now (the ORIGINAL battery from '96 finally died; can you believe that? The original '96 battery!). They never heard "the sound". It's real hard to daignose something if they never hear what I'm talking about.

Please see the enclosed pictures. One pict is of the entire engine compartment from the front. I have a 3.1L V6. The other pict is a closeup of the center of the engine. The red circle indicates the approximate area where the sound seems to be coming from, either at the firewall, possibly from that octagon-looking box attached to the firewall, or that same location behind the firewall.

--- PROBLEM POSTING IMAGES; PLEASE TRY THESE URLs ---

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"http://img156.echo.cx/img156/5457/040305enginefrontviewmod1small.jpg"

Note: this "mystery box" (that octagon-looking thing) is above the heating/air conditioning unit. Can anyone tell me what this is? The Cust Service guy at the dealer thought it might be the cruise control, but I do not have cruise control in this car. Another guy at the dealer, the former service manager (now retired), had one of his mechanics come out and have a look, but he couldn't say for certain what it was, either.

I am afraid that if I keep driving the car, then eventually whatever is happening here will completely fail. The retired Service Manager rode with me awhile, during which the car was completely quiet, of course. He says that the problem I've described doesn't sound like anything that will strand me, or that will cause a safety problem. He recommends that if whatever it is becomes more consistent, and the sound can be heard by somebody else, then maybe they might know what to look at to determine a diagnosis. The only problem with that is that I fear the problem will completely fail and cause serious damage that is both uncovered by the powertrain warranty and more expensive to repair than I can handle.

Any suggestions???

By the way ...

Can you recommend a decent, user-friendly repair manual?

I have Chilton's manual, but it is for multiple vehicles (Celebrity, Century, Ciera, 6000) from 1982 to 1986. It doesn't tell me anything about this problem.

Thanks in advance for any help you can give.

--ShaunMac

[Wheel7]

Originally Posted by ShaunMac

Hey, Y'all ...



Note: this "mystery box" (that octagon-looking thing) is above the heating/air conditioning unit. Can anyone tell me what this is? The Cust Service guy at the dealer thought it might be the cruise control, but I do not have cruise control in this car. Another guy at the dealer, the former service manager (now retired), had one of his mechanics come out and have a look, but he couldn't say for certain what it was, either.

Any suggestions???

By the way ...

Can you recommend a decent, user-friendly repair manual?

I have Chilton's manual, but it is for multiple vehicles (Celebrity, Century, Ciera, 6000) from 1982 to 1986. It doesn't tell me anything about this problem.

Thanks in advance for any help you can give.

--ShaunMac

I don't know about the noise, but I was looking at the octagon shaped box on my 96 Century wagon with cruise today. I found that if you grab it on the drivers side, the cover will snap right off. There are 2 catches on the passenger side of the cover- make sure to use the right one when replacing the cover.
All it has in there is a cable from the gas pedal and a cable to the engine. they are linked inside the box with a sort of semi-pulley like mechanism. it looks like it is all mechanical from what I can see.

I have a Haynes 1982-1996 book and it is also for multiple models. I did not see anything about the noise problem.

[ShaunMac]

Originally Posted by Wheel7

I don't know about the noise, but I was looking at the octagon shaped box on my 96 Century wagon with cruise today. I found that if you grab it on the drivers side, the cover will snap right off. There are 2 catches on the passenger side of the cover- make sure to use the right one when replacing the cover.
All it has in there is a cable from the gas pedal and a cable to the engine. they are linked inside the box with a sort of semi-pulley like mechanism. it looks like it is all mechanical from what I can see.

I have a Haynes 1982-1996 book and it is also for multiple models. I did not see anything about the noise problem.

Hi,

Thanks for responding to this post.

However, I have since resolved this problem. I traded it in on another vehicle.

Wouldn't you know, it started complaining grievously on the way to the dealer; I'm lucky I made it there in one piece! It was as if it knew what I was up to. A little Christine in this vehicle, maybe? Well, sorry, Christine ol' girl, I don't have the time, and I sure don't have the money for your tantrums!

Would I buy a Buick again? Possibly. But as with every car, I have since learned to give it a complete inspection before closing the deal, and even then to have reserve funding available in case of anything.

"'Bye Buick," I said, as I waved to it from my brand new car and drove away. No more rattle-rattles for me .... for NOW, that is!

--ShaunMac