Hello fellow Škoda owners,

I need some help with diagnosing a strange sound that can be heard on startup of my Škoda Fabia MK1 Combi, 1.9 SDi. It's left hand drive vehicle and the sound can be heard from the right side of the hood, behind the passenger's side dashboard. 

 

The sound can be heard mostly on startup of the car, especially in the morning in the cold weather. It's like an electrical hum, it's not squealing or brushing, it's like that low noise which you hear when you blood pressure is high. It stops after some time and then it doesn't start again till the next morning, no matter how many times I start my car that day. Car needs to to be parked for some time for the sound to be heard.

I suspect that maybe it's the alternator's bearings/brushes, but I'm not sure. My logic is that the cold weather depletes more of the battery power so the alternator works more on startup till it fills the battery.
Problem is that it's random so I would like to narrow it down before going to a mechanic because it's very hard to replicate.

 

Any advice is appreciated.
Many thanks.

 

 

Edited 24 October, 20241 yr by Boslo

Try a length of garden hose. One end to your ear and move the other around the engine compartment. You should be able to isolate where the noise is coming from or at least the general area. It could be power steering pump? If the fluid is old it and has too much moisture in it it can sound like a groan or hum till it warms up. Its normally worse when cold weather or start up.