Alfa Romeo Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1 (Edited)
Hello all

Well actually I'm getting like a buzzing noise when the car is started(Spider S3 1989). It sound like electric, it's coming somewhere close to the fuse box , and If I press the brake pedal and it disappears. After you release the brake pedal it takes like 2 seconds to come back. I'm afraid it could be related to a shortcut on the system or something like that. It's not loud but after 40 minutes of driving it starts to make me crazy.

Regards
Miguel
 

·
But Mad North-Northwest
Joined
·
10,535 Posts
I'd guess a leaking brake booster. Try plugging or clamping off the vacuum line to the booster: if the sound goes away you've found your problem.

If it were just something electric it would probably be doing it with the key on but the engine not running.
 

·
Super Moderator
Joined
·
10,634 Posts
I'd guess a leaking brake booster.
Good diagnosis! I can't imagine anything electrical that would go away after braking.

Try plugging or clamping off the vacuum line to the booster
Note that the hose should be detached at the booster and plugged there. That is, you don't want the engine to be sucking air in through the hose. Just stick a bolt into the hose and secure it with a hose clamp.

If your brake booster is still functioning, your pedal will feel different (harder) with the vacuum hose disconnected. As long as you are prepared to push the pedal harder, there isn't anything dangerous about driving this way until you can get a new or rebuilt booster.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #4 (Edited)
Thanks for your reply, I will check but actually the noise is not coming from the booster, it comes somewhere close to the fuse box. The sound is more or less like this one


I don't know if the fact that I have replaced the original alternator, with one for a 164 has something to do with this issue.
 

·
Premium Member
Joined
·
1,103 Posts
Either a phaser on overload or the dilithium crystals are failing :).

Try pulling and re-inserting all the relays in that area. Check their contacts. Put a piece of tubing to your ear and try to isolate the sound by moving from component to component.

Also, may be related to the fact you have not filled in your signature line :).

All the best.
 

·
Super Moderator
Joined
·
10,634 Posts
Thanks for your reply, I will check but actually the noise is not coming from the booster, it comes somewhere close to the fuse box. The sound is more or less like this one.
Well, as I wrote in post #2, I'm having trouble imagining what electrical source would produce a buzzing noise that stops when braking. Two wild ideas:

- There is nothing inherent about a 164 alternator that would cause buzzing. You generally need AC current to get an electrical component to buzz. If your alternator had a bad diode, it might put out something like AC. Question: Does the frequency of the buzzing vary with rpm?

- Alfas of certain model years had seatbelt buzzers; is it possible that's what you are hearing? They are located behind the dash, near the fusebox.
 

·
Registered
Joined
·
2,045 Posts
There is a buzzer located on the inner fender wall - inside the passengers compartment close to the fuse box. It is a warning buzzer for something which I can't remember - maybe seat belt warning or something like that. It is a white square thing with wires attached on the bottom. It looks like the black relays on the fuse box but is white, if I am remembering correctly. Look up under the dash near the fues box and if you see it, disconnect it. If this stops the noise, then you can try to figure out what the thing is, or ignore it and leave it unplugged.

Robert
 

·
Registered
Joined
·
17 Posts
Discussion Starter #8
Either a phaser on overload or the dilithium crystals are failing :).

Try pulling and re-inserting all the relays in that area. Check their contacts. Put a piece of tubing to your ear and try to isolate the sound by moving from component to component.

Also, may be related to the fact you have not filled in your signature line :).

All the best.
:laugh: That's for sure, the other night my girlfriend got a headache because of that sound, but I don't mind about her she will be fine, I'm worried about my car :)

Yes I´ve done that, actually do you know if it's normal that the turn signal relay is always hot?(I don't know if that's the correct name) that's a different issue, because I have removed it and the problem persist, but that's the only one that is hot even if I'm not using the turn signal or the emergency lights.

Well, as I wrote in post #2, I'm having trouble imagining what electrical source would produce a buzzing noise that stops when braking. Two wild ideas:

- There is nothing inherent about a 164 alternator that would cause buzzing. You generally need AC current to get an electrical component to buzz. If your alternator had a bad diode, it might put out something like AC. Question: Does the frequency of the buzzing vary with rpm?

- Alfas of certain model years had seatbelt buzzers; is it possible that's what you are hearing? They are located behind the dash, near the fusebox.
Thanks again, well the frequency doesn't change when I rev the car, but it happen just when the car is hot(that makes it even more strange for me), I was trying to take a video of my buzzing noise yesterday, but it never came. Actually I remember that last week I was checking on this issue, and there is like a white piece that is pressed by the brake pedal, and I was wondering if that switch could be causing the buzzing noise. I will check if I have seatbelt buzzers.


There is a buzzer located on the inner fender wall - inside the passengers compartment close to the fuse box. It is a warning buzzer for something which I can't remember - maybe seat belt warning or something like that. It is a white square thing with wires attached on the bottom. It looks like the black relays on the fuse box but is white, if I am remembering correctly. Look up under the dach near the fues box and if you see it, disconnect it. If this stops the noise, then you can try to figure out what the thing is, or ignore it and leave it unplugged.

Robert
Thanks. My fuse box is on the drivers side, but I would check that if they are located in the same location that you are telling me. I will make a research on that because it sound like something that could be happening to me.
 

·
Premium Member
Joined
·
1,939 Posts
Earlier when you mentioned the sound going away when you pressed the brake, the only thing I could think off was the brake light switch, but too wouldn't think that could buzz, so I never mentioned it, but who know's. Can you not chase the buzz by sound and feel, being careful not to zap yourself.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #11
Earlier when you mentioned the sound going away when you pressed the brake, the only thing I could think off was the brake light switch, but too wouldn't think that could buzz, so I never mentioned it, but who know's. Can you not chase the buzz by sound and feel, being careful not to zap yourself.
I will check that switch, because I was hearing the sound coming from this part, who knows maybe I got a transformer and I'm not aware.

Miguel, the other end of the brake booster is inside the car where the pedal box mounts to the firewall directly behind the fuse box. Try the test as suggested.
That makes a lot of sense, so I will hear the buzzing sound inside the car, not from the engine side. As soon as I get home I will test, thanks.
 
1 - 11 of 11 Posts
Top