Help! Knocking noise at 70/80mph

[MisterCal]

So I've been doing a few motorway drives and my car has got a horrendous knocking/drumming noise at around 80mph.

It sounds like its coming from the rear of the car!

I first thought it was the tension on the rear wiper blade being loose causing the noise so replaced that but the noise is still occurring.

Any advise/help would be appreciated!!

 

[RUM4MO]

Maybe it is the speed warning??

Seriously though, maybe check the tyres as some might have structural damage, this might require lifting the rear up and checking the tyres by rotating them.

 

[MisterCal]

Yeah I thought tyres but they are nearly new with no cuts or damage from what I can see... Thanks for the advice though!


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[andycupra]

undertray?

 

[RichyH]

I had a similar (maybe not the same) but sounded more like a vibration at 90mph, one of my rear alloys had buckled causing the noise


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[MisterCal]

I wondered if it might have been the wheel balance weights? But surely that would make a noise at low speed too?


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[RichyH]

No not necessarily, it'd cause uneven tyre wear and handling issues for sure, which you'd notice more and would be a bigger concern im sufe! I'd get the wheels/alloys taken off and looked at for damage, and get them balanced while your there and the wheels are off? Even more so if your due a new set. I only found the buckle when i got my alloys painted, as nothing obvious was causing it


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[MisterCal]

Cheers for the advise Richy, haven't had any handling issues but might be worth getting a second opinion on it... definitely gunna have a full check over at the weekend, just hoping it's nothing too $$$!


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[RichyH]

If you ask about checking that they are balanced properly because of the issue, rather than can you balance them after checking my alloys, they may even give you a bit of leway pricing wise? Worth a shot. Check the garage has a balancing machine though!! Should be on the website, save showing your hand too early


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[RichyH]

Balancing isnt too bad for price mate, neither is a alloy repair, simple solutions, fingers crossed!


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[MisterCal]

Yeah I've got a garage I go to and get 50% off labour, it's just a motorway drive away!! Worth the risk? I think so!


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[RichyH]

Yeah too right


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