another vague 'vague noise' thread?

magicbastarder

got the front driver's side main suspension spring replaced in my 11 year old octavia last week; didn't use it really till fri evening and noticed a high pitched creak and occasional 'loose' knocking noise when going over bumpy roads/speed ramps. so i'll be ringing the mechanic about that on monday morning anyway.

however - i also noticed a noise, not a whistle, almost like a noise you'd make halfway between exhaling and a low pitched whistle; but only when taking my foot off the accelerator, typically at speeds of maybe 50km/h or more. hopefully a simple question - could that be explained by the suspension needing a tweak, or could that be something new, unrelated to the work that was done last week?

if i leave the car in gear or knock it into neutral, it doesn't change the noise.

Leatra

This comment will be no use, I'm sure, but I've actually noticed exactly the same sound as in your second paragraph in my 2017 Ibiza, albeit mostly at lower speeds rather than higher. It first registered the other night, when I was driving with the windows down and trying to localise a squeak in my suspension (also driver's side) that I had picked up after accidentally flying over a road made of potholes in West Cork, so I suspect the two noises might be connected. Google searches suggest that both could be due to a wheel bearing. I'm hoping to get it looked at by my mechanic whenever I make up my mind whether the squeak is front or back.

magicbastarder

2017 is reasonably new for a wheel bearing to be gone, is it?

BlakeS94

That little whistle sound sounds like the Turbo spooling down or the wastegate venting excess exhaust gas, both are completely normal If you have to try to hear it and it's only when letting off the accelerator.

You might notice it a bit more If you're driving with higher revs and suddenly let off the accelerator.

magicbastarder

it wasn't happening before the car went in for the work on the spring though.

how long would the noise last if it was the wastegate? this is more 'constant' than i would have expected from a venting noise.