Astra H 1.6 Squealing Noise Off Throttle

Astra H 1.6 Squealing Noise Off Throttle



Original Poster:

5,514 posts

156 months

Monday 20th July 2020
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Morning everyone, I'm having an unusual noise coming from my Astra H, and am a bit baffled by it. Google isn't helping as it's coming up with about 20 different things.

Everything's good on start up, and short journeys don't bring the issue up, but after a while, usually when the car's warmed up properly after a run up the motorway, it makes this weird high pitched 'squeal', it's hard to describe but the most accurate way of describing it is like when you run a wet finger round the rim of a crystal glass.

It only does this when off throttle, either moving or stationary. As soon as my foot goes on the accelerator pedal, it shuts up. Then after a second or two off throttle, it starts again. I managed to capture a video of what's going on, link here

I've seen numerous suggestions as to what it could be. Alternator, cam cover diaphragm, could be that belt or a pulley, one suggestion even the water pump. I'm hoping that someone knows what this could be, as I'd rather not go through replacing every single component and spending more than the value of the car on it; this is meant to be a stop gap until I've got a bit more behind me to buy a better car (was made redundant earlier this year, had company car, now have job without company car). Any help greatly appreciated