Technical Chirp noise from engine

[benoliver999]

We just went over a speed bump and now there's this noise coming from the engine:

https://www.bfoliver.com/files/2025-01-16-panda-noise.m4a

I've not had a chance to properly inspect yet but I thought I'd seek out opinions on what it could be.

1.2 petrol engine. With air con (but switched off I think, will double check).

Car was out of gear on this recording.

Judging by other threads it seems like maaybe around the alternator. I'll try and get a better look in the daylight.

 

[koalar]

Does the noise alter if the clutch is up or down

Assuming it doesn't

Try flipping the auxiliary belt off

 

[benoliver999]

https://www.bfoliver.com/files/2025-01-17-panda-noise.m4a

that's the sound when I press the clutch

I'll see if I can get the belt off, but space is limited here

 

[DaveMcT]

A noise that happens when you press the clutch is the release bearing
A noise that stops when you press the clutch is the gearbox input bearing
Both noises come from the battery end of the engine.

Noises from the back of the engine (diagonally opposite to battery) especially on cold start could be alternator bearings or rusted up stator fouling the rotor. That often cracks the alternator case.

Squeals from belt end of the engine is likely the accessory belt slipping. Remove belt and check the alternator and AC for free running. Check alternator case for cracks.

 

[benoliver999]

It's definitely on the other side to the battery. Quite loud so hard to place exactly. The noise happens regardless of the clutch. It's gonna have to be a garage job I fear because where I am at the minute I cannot get the wheel off to check the belt

 

[koalar]

It's definitely on the other side to the battery. Quite loud so hard to place exactly. The noise happens regardless of the clutch. It's gonna have to be a garage job I fear because where I am at the minute I cannot get the wheel off to check the belt

Other side from the battery

Alternator
Idler
Compressor

Sounds like a bearing to me

Flick the belt off and make sure the sounds gone

And then spin each individually should narrow it down to the faulty component

If it is a bearing it's probably fine to drive a few miles, there's no guarantee

 

[benoliver999]

Took it to my local garage. Noise stopped of course just as I pulled away. Anwyay the belt looked iffy so we put a new one on ¯\_(ツ)_/¯

 

[DaveMcT]

Mine made a screech noise on engine start. It turned out the alternator was corroded. The casing was cracking and rotor binding. New alternator no more noise. Within days, the old alternator was locked up solid. Same thing happened on a BMW bike which uses a car style alternator.