New hissing noise f...
 

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New hissing noise from VW diesel

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Passat has developed a new noise recently which seems to be a rhythmic hissing or scraping sound.

Long shot, but before I either ignore it until something detonates itself, or give in and pay a garage a small fortune for an opinion, has anyone got any ideas of how I could narrow this down?

https://streamable.com/161dgq

It's a 2015 2.0 diesel with a 6 speed manual box.


 
Posted : 26/02/2024 6:01 pm
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That's a scraping of metal on metal, probably just a dead bearing or bushing. I don't know what it is but I'd not be ignoring that.


 
Posted : 26/02/2024 6:10 pm
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Can you locate the source with a hammer against your ear?


 
Posted : 26/02/2024 6:12 pm
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I am in the "ignore at your peril" group.


 
Posted : 26/02/2024 6:14 pm
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I was going to ask if it’s a Pssss-at but it is so that rather takes the wind out of the joke.


 
Posted : 26/02/2024 6:25 pm
 jca
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Checked for snakes?


 
Posted : 26/02/2024 6:44 pm
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That sounds like bearing or similar that's dry.
Don't ignore.


 
Posted : 26/02/2024 7:12 pm
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Sounds like it might be an auxiliary connected to the serpentine belt, access via wheelarch??


 
Posted : 26/02/2024 7:13 pm
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Do you think it might be the windscreen vipers? Or a fuel issue possibly, maybe he should try an addertive.


 
Posted : 26/02/2024 7:13 pm
hardtailonly, alanw2007, hardtailonly and 1 people reacted
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👏👏


 
Posted : 26/02/2024 7:14 pm
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Username checks out 👍


 
Posted : 26/02/2024 7:14 pm
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*groan*


 
Posted : 26/02/2024 7:15 pm
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Came for the advice, stayed for the puns.

It's due a full service soon so I'll bring that forward and ask them to check the noise out while they're on.

Since it's a VW I'll preemptively phone the bank manager to let them know they won't be needing to look after my cash anymore for a while.


 
Posted : 26/02/2024 7:17 pm
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The period of the sound suggests it's something to do with the auxiliary belt or the timing belt, to me. There's a cover on the timing belt you can pop off and watch it as it goes round. Look for frayed bits or something.


 
Posted : 26/02/2024 8:50 pm
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Frayed or delamination cambelt would be my guess


 
Posted : 26/02/2024 8:56 pm
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Timing belt and water pump were changed one year ago but doesn't mean they were installed properly I suppose.


 
Posted : 26/02/2024 9:12 pm
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Sounds like a belt to me.


 
Posted : 26/02/2024 9:24 pm
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Don't delay in checking it out if it is a timing belt, get it checked ASP


 
Posted : 26/02/2024 9:27 pm
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If you suspect a belt it can work to spray a bit of silicone spray on it to see if it changes the sound


 
Posted : 27/02/2024 1:13 am
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If you want to inspect the timing or auxiliary belt you could remove the cover, jack one wheel up, put it in top gear then turn the raised wheel which will turn the engine over slowly.


 
Posted : 27/02/2024 6:43 am
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Agree with the above - the timing of the noise suggests aux belt, or something connected to it. Probably not the timing belt if that was done recently.


 
Posted : 27/02/2024 1:26 pm
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"If you suspect a belt it can work to spray a bit of silicone spray on it to see if it changes the sound "

I agree, but don't use silicone! Try giving any visible belts a squirt with a water sprayer while the engine is running - if the sound changes it's a slipping / worn belt.

Was the cambelt tensioner changed at the same time as the belt?


 
Posted : 27/02/2024 1:54 pm
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Its the speed and frequency for an aux belt, belt pulley, tensioner, A/C pulley or suchlike.

Easily confirmed with a quicksquirt of GT85 etc onto the belt and pulleys - if it dissapears, thats your noise.

No, this is not a fix. but it confirms the source of the noise.


 
Posted : 27/02/2024 2:27 pm
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It looks a bit frustrating to get the cover off to inspect the belts as there's a lot of hoses and pipes going past it. Knowing my luck I'd break a connection trying to move them and cause a bigger problem!

No idea if the tensioner was done along with the belt - it seems to come as part of the timing belt kit so you'd assume so but you never know.


 
Posted : 27/02/2024 2:37 pm
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Bugger. Tried a few independent VW garages around here and all booked up for at least two weeks and suggested I probably shouldn't be driving it in the mean time.

Given it has some other annoyances and recent repairs I've already shelled out for I'm extremely tempted to just cut my losses and trade it in...


 
Posted : 28/02/2024 4:36 pm
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Is it an estate?


 
Posted : 28/02/2024 4:40 pm
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Yes, B8 estate.


 
Posted : 28/02/2024 5:03 pm

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