Strange "electrical/pressurised fluid noise" in car engine

Gammawolf

Gammawolf

Gammawolf

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Hi All, wondering if any car gurus can help identify a strange sound.. Background is that this is a new to me car (2019) so i don't know what is normal and what isn't and want to get back to them quickly if it isn't right.
I have this almost arcing/electrical sound coming from the engine but i can't really pin point it. The sound starts when the car "wakes" up. ie i open the door or put in the key in ignition without turning it. Or for a bit after i've turned it off the engine and removed the key. I do not know about when the engine is running as its hard to hear over the noise.
There is also another type of noise thats more like a hum which i'm not bother about as it sounds like normal operation. The electrical sound seems come and go with the hum but is offset by a few seconds when the both disappear.

"Electrical" sound

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Hum (you can still hear the other sound in the background, not bothered about this one, only really putting this here for completeness as these are the two noises its making)

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First one isn't unusual to hear after a longer run as the vehicle settles down - stuff doesn't just turn off immediately things will tick over a bit for cooling purposes, etc., less usual to hear when you first open the door/start up though.

First thing you'd want to do really is check the battery voltage with a multimeter - if it is low things can operate a little weirdly like lights flickering and other stuff almost failing to work but just about starting making strange noises as they do, etc.

Second one sounds like possibly the AC/environmental control on low duty cycle.
 
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Yeah, second sound to me is some sort of pump etc just pressurizing things, brake fuel, who knows but it sounds health :D

Just did some measurements, getting
14.1v with the engine on and alternator running
12.7v with the car "off" and no sounds
12.4v with the car "woken" up and the sound

Just as a sequence of events it seems that the crackling electrical sound turns off about 4 seconds before that low hum turns off after the engine has ran (for about a minute) and its settling down. They come from distinct locations each, the electrical sounds from the rear left side of the bay when looking in, and the hum is from around the front right side, fairly near the block. Again just provided this as reference, its the electrical sounding thing thats bothering me.

Going to try to see if i can locate exactly where its coming from, think i've got some tube i can use as a stethoscope of sorts to help with that
 
Fuel pump primes as soon as driver door is opened and after driving modern turbo cars have a pump to cool the turbo so that the sitting there with the engine idling after driving hard is a thing of the past.
 
Is it diesel, in so much that the cylinder fuel rail is running at a higher pressure ... plus the sender pump at the tank, as a potential noise source.

Not sure if the engine management units typically have a fan of some kind too - have often thought I hear such a noise in bm.
 
jpaul said:
Is it diesel, in so much that the cylinder fuel rail is running at a higher pressure ... plus the sender pump at the tank, as a potential noise source.

Not sure if the engine management units typically have a fan of some kind too - have often thought I hear such a noise in bm.
Click to expand...
Cylinder fuel rail pump is powered by the engine. You kinda need that running first…

Do bots have cars then?
 
Fuel pump.

Also my Volvo makes similar wierd ******* noises apparently it tests something in the brakes (can't remember) and some other servos it says it in the manual which I did actually (sort of) skim read once.

If it's made in 2019 the dash board would light up like a Christmas tree if there was anything actually wrong.
 
I'm still at a loss as to whats actually making the noise :( This won't set your pants on fire but for reference its a Vauxhall/Opel Combo Life with the 1.2 petrol (PSA group car so is effectively the same as Citroën Berlingo, Peugeot Rifter). Having trouble finding out a proper fuse box diag, owners manual is useless. The engine compartment box for the Corsa F is the same layout and matches with the few fuses listed in the owners manual so i tried pulling various fuses from here to see if the device would turn off https://fuse-box.info/opel-vauxhall/opel-vauxhall-corsa-f-2019-2020-fuses

No instance of fuse pulling affected the noise, i did both brake systems, both fuel pumps but can't be sure they are even right since this is for a corsa. The noise seems to be coming from behind the block/ or something attached on block on the back left side from using my tube and poking it around. I'm fairly sure its not the cooling pump for the turbo (the one making the hum noise), when the car wakes up i can feel it moving liquid through the turbo and several tubes (which are on the other side of the engine). The cooling pump turns off about 3 to 4 seconds after the crackling noise when the car settles down. Might have to try to look from under the car, top hasn't got great access to the back.
 
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