What's the buzz?

[Nosevi]

When I turn my ignition on prior to engaging the starter motor there's always been a buzz from forward of the dash, some form of relay I think? Have heard it on other 348s and it's been there every time I've started my car for 12 years. Never really questioned it.

Got in the car to start her up and load her onto the trailer to go for her service, turned the key........... no buzz, total silence. Thought here goes, going to have the embarrassment of my car not starting for the first time ever just when the transport is here Only she started as normal and everything seemed to work. Switched her off, tried again and again no buzz, complete silence but all systems functioning and she ran perfectly. Bit baffled.

Anyway, what's that buzz that's always been there pre starter, where's it gone, and given it has why does everything still appear to work?

[A348W]

Had the same buzz on the 348 i had. Thought it was the brake system doing something as the brake and abs light would be on until it stopped. not sure what it was doing; never looked.

[Nosevi]

Had the same buzz on the 348 i had. Thought it was the brake system doing something as the brake and abs light would be on until it stopped. not sure what it was doing; never looked.

I asked the dealer to look at it when she went for her service but she's come back still without the buzz, from what they said I'm pretty sure they forgot to look into it. She sailed through her MOT while there so I'd doubt it's brakes but I guess it might be ABS - is that checked during an MOT as in if it's fitted that it's functioning?

[A348W]

I asked the dealer to look at it when she went for her service but she's come back still without the buzz, from what they said I'm pretty sure they forgot to look into it. She sailed through her MOT while there so I'd doubt it's brakes but I guess it might be ABS - is that checked during an MOT as in if it's fitted that it's functioning?

abs pump rings a bell but cant remember; but only runs if needed. mire than likely a few threads on fchat about it.

[Nosevi]

abs pump rings a bell but cant remember; but only runs if needed. mire than likely a few threads on fchat about it.

Cheers Adrian.

Just went out, turned the key and got the buzz together with ABS light which then went out when the buzz stopped. Tried again a few mins later and no buzz, ABS light did come on but went out quickly. Think you're spot on and once pressurised the system just does a quick check. Possibly when I started the car to load it up the other day I had already turned the key earlier to put a window up and the system pressurised then so didn't need to later. Perhaps the system keeps pressure for quite a long time once it's been charged if the brakes aren't used. So to be fair on the dealer perhaps there wasn't anything to look into

[cgt]

I remember that on all my 348's, cant remember what it was and never bothered me

[irarref]

Deffo the ABS

If you've not used your car for a bit it may take some time before the pump/light/buzz stops.

You can hear it here (and if you open your bonnet and lift the access panel and unscrew the lid on the resevoir you can see the brake fluid level drop as the system is being pressurised.

https://youtu.be/CQ9qbjuqwR0

[Nosevi]

I remember that on all my 348's, cant remember what it was and never bothered me

didn't bother me either......... until it wasn't there

Deffo the ABS

If you've not used your car for a bit it may take some time before the pump/light/buzz stops.

You can hear it here (and if you open your bonnet and lift the access panel and unscrew the lid on the resevoir you can see the brake fluid level drop as the system is being pressurised.

https://youtu.be/CQ9qbjuqwR0

Cheers Jeff. It's back now, as I say must have charged it earlier and I guess it holds the pressure for some time so doesn't need to do it if you turn the key again just a few minutes later.

[irarref]

If you look at pages G41/42 in the workshop manual it explains what is going on.

[Qavion]

"MARCIA" = ACCessory in case you didn't realise.