Computer noises?

A couple of days ago, while driving only about a quarter mile, my car started making very strange noises about half way through my drive & also after I stopped. The noises occurred no more after I turned the engine off or after I re-started the car. I’ve never heard a car make such noises. Sounded like it was probably coming from the dashboard (but not sure). It wasn’t music, but sounded almost like music… although my sound system was turned off! I’m wondering whether it was the car’s computer system making the strange noises. There was no type of warning lights showing. Any ideas?

I have a 2004 Buick Century; 4-door Sedan; Automatic Transm. (4speed) w/overdrive; V-6 engine 3.1 L

Sometimes the fuel pump can start making noises.

Have someone ride in the back seat when this noise occurs. If the noise is louder in the back seat it could be the fuel pump making the sound.

Tester

Can you describe the noises better? The car’s computer has no speakers or other audio outputs and is completely silent. No moving parts either. Some cars use the audio system though for chimes and alerts, such as if you leave your headlights on. There could also be an amplifier for your audio system that is staying on and picking up electrical noise from somewhere, even if you have the stereo off. Without knowing what the noise sounds like we’re all just guessing though.

If the noises are really coming from inside the dashboard, then I think the most likely cause is malfunctioning of one or more “blend doors” inside the HVAC system. When the servos are trying–but not succeeding–in closing a blend door, there can be some strange noises.

If the 2004 Buick still uses vacuum controls for the HVAC it could be a vacuum leak.

All good advice here but I think @oblivion may be on to something. My wife keeps a headset for the radio in the vehicle and we found it was picking up AM signals even when the radio was off. She now unplugs it and stashes it in the glove compartment when she’s not using it. The only other time that I’ve seen this is with B-52G headsets for the ground crew. AM radio would play on them if the main headset cable (aircraft to technicians) was shorter due to repairs.

Thanks for all the comments! I can’t describe the noise any better. It’s only occurred the one time so far. If I find out more, I’ll let you know.

Here’s some additional info that may be relevant:
A couple of times recently my “Anti-Lock Brake” light (and my “TRAC OFF” light) have come on, but then do not re-appear after re-starting the engine. There are NO brake symptoms (pulsing of the brake or moaning noises). This occurred also some months ago, and then ceased.
Also, for a couple of weeks my car has begun leaking a drop or two per day of some type of fluid from under the front of the car (doesn’t seem to be oil).
I don’t know if these things are all related. Any ideas prior to my taking it to the shop?

Your ABS and TRAC warning lights are due to a fault in the antilock braking system. Often this is a failing wheel speed sensor–if the computer can’t accurately tell how fast each wheel is turning, it can’t tell if you’re skidding and the system will be disabled. Since the traction control uses components of the ABS to apply the brakes to the wheel that’s spinning (and tell if it’s spinning), it is disabled too if there’s a fault.

Leaking fluid could be anything. Without a better description, who knows? It’s like saying I live on Main Street, come visit me, without knowing the street address or even what town.

I don’t see how these problems could be related.

It might help if you can describe the noises.

I agree that a description of the noises would be helpful, but I think that it is more important at this point for the OP to focus on the leak of unknown origin and the ABS problem.

The OP needs to have the car examined by a competent mechanic, in order to determine the source of the leak, but I would suggest checking both the brake master cylinder and the radiator before driving it again, just to make sure that the car is not low on either brake fluid or coolant. If all is well in those two areas, then a visit to a mechanic is in order, with an emphasis on finding out the source of the leak as well as the cause of the ABS problem.

While it is in the shop, perhaps the OP can demonstrate the noise problem, and have that addressed also.
I suspect that this 10 year old car–with unknown odometer mileage and an unknown maintenance history–has multiple problems, some of which are likely trivial, and some of which could be…important.