Knock Knock on the GTA

Having an issue with a knocking noise coming from the off-side front wheel, and its only happening after travelling at speeds above 60mph for about 10 minutes or longer
When I come to slow down i.e.: slip-roads or turning, there’s a rotational knocking noise, and it continues for a while (about 10 minutes) and then disappears, until I start travelling at speed again and reappears when I come to slow down.
Its not brake related because the noise continues with or without the brakes applied, I’ve had the wheel off myself and carried a visual check for all the obvious problems like wheel weights or callipers catching, loose pipe work……….., nothing, it all looks perfect.
So I have had her checked out with two Alfa dealers, both reported, they couldn’t find any problems or any noise coming from any of the wheels, both dealers have checked all the suspension and links, along with drive shafts, again, both said everything was in order.
To be honest I really didn’t think that they believed me, so I took one of the mechanics for a drive, blasted her down the 42, and sure enough the knocking started. So we took her back to the garage and onto the ramps, 4 mechanics checked and worked on her for about 45 mins, and still they couldn’t find anything untoward.
She’s back in on Monday for a complete inspection, so just wondered if any other members have had the same or similar symptoms.

Its only after travelling at speed, nothing is apparent for normal town driving, and it only appears when I take the foot of the gas to slow down, and can be heard during braking, and non-braking movements. Turning the wheel doesn’t change anything, its still happens on both locks.

Any idea’s anyone ?

I'm wondering if it's gearbox/diff related..

How about swapping wheels, at least to rule out as the cause, could the tyre above a certain speed and temperature be deforming and causing the noise somehow?

Reminds me of the time... thought a CV joint/boot had gone as I was getting a clicking only on full lock, got someone to listen from the outside to try and discover the whereabouts, turned out to be a screw in the tyre, just the head of one in the end so no damage fortunately.

Or maybe a wheel balance weight is catching a brake? Unlikely though.

Could it be related to bodywork in that region - maybe speedbump damage? Something worked a bit loose from the the wheel arch area that starts knocking when forced to shift at speed and under breaking?

There's nothing more frustrating than taking a car to a garage for a problem that either disappears when they try to track it down, or they can't hear...

OA Thanks for that !
Hope not ! ......its Q2 and its not 4 months old yet, plus I think you would here it all the time, even when slow driving around town.
Anyway should find out Monday, I will keep you posted.

Caldo
Thanks for the reply, when I did my first visual I swapped the wheels around, and it still continued,even tried adjusting pressure in the tyres to no avail.
I'll keep you posted

Could be driveshaft..

I had a noise in my car everytime i would be on a slight bend i would hear a rotational loud rubbing noise. People on here suggested driveshafts and other very expensive stuff. after carefull eamination i found out that the discs were very worn and they had formed a lip which was rubbing against the shields every time i was in a bend. Changed the discs and the noise went away and never came back.

Newalfist thanks!
Brake discs are new-ish less than 5000 miles along with pads, and there are no signs of any rubbing anywhere, discs look brand new, callipers look like they came out the box yesterday, not a scratch or mark anywhere, same for the heat shields.
Trailbraker suggested Driveshaft, this was my train of thought to start with, unfortunately both garages report driveshaft’s to be OK so that knocked that idea on the head. Plus with a driveshaft you may hear a lot more at lower spends and on full locks, she runs fine on both locks without any problems.
Anyway wish to thank all for their posts, should or hoping to have a definitive answer by Tuesday.

the driveshaft on that side is in 2 parts. mine went recently and a well known alfa 'specialist' close to cambridge failed to diagnose it so I changed it myself. If the inner one that goes, jack up the car, remoe the wheel and inspection panel from the wheel arch, then grab the shaft (ooer) near the inner mount and move it about. you will probably feel it 'clicking'

Well got her back today, cost me over £500 new cam belt and tensioners fitted yet again,that's two Cam belt changes in less than 20k.
Cause: Crankshaft woodruff key broken and crankshaft gear worn,
Good old Alfa Customer Care payed up for half the bill, took a bit of fighting ! anyway "thanks Sam"
Dealer advised changing the water pump, which would have been stupid not to do so at the time, quoted me approx £100 for the new pump. Thinking that was a bit OTT called EB spares, they quoted £75 all in, and thats the upgraded pump.
Before picking the car up, the dealer called, to inform me she ( the car ) was ready, plus what all this was going to cost, he then comes up with a price of £180 for the replacment waterpump. What ! said I could have 2 and half from EB spares for that money, "best sort something out before I arrive " . Got it down to £80 and the engine coolant was free " cheers Paul your not so bad, its a pity your a Villa man ".
So.............
A lesson to all, after a Cam Belt failure, or a rebuild, if you hear any Knocking sounds from the drivers front wheel, more so after the engine has been loaded ( traveling a speed ) get it back to the dealer ASAP, I was lucky it could have been a total rebuild at cost to me

Originally Posted by karlo17

Cause: Crankshaft woodruff key broken and crankshaft gear worn...

Please tell me the part numbers for the crankshaft woodruff key and the crankshaft gear.. they're probably on the receipt.. i think i need to do this on my GTA, quickly..before valves get bent.....

Thanks for the post..

Stephen Manjai
Looking at the repair invoice, the only reference to a key that is listed is Part No A0010554220 costing £1.06p. I will check this out with the dealer tomorrow, before I can confirm the correct part.

Originally Posted by ukoldschool

the driveshaft on that side is in 2 parts. mine went recently and a well known alfa 'specialist' close to cambridge failed to diagnose it so I changed it myself. If the inner one that goes, jack up the car, remoe the wheel and inspection panel from the wheel arch, then grab the shaft (ooer) near the inner mount and move it about. you will probably feel it 'clicking'

Ukoldschool thanks for you post
Problem has been sorted now, basically down to bad workmanship performed by an Alfa Franchise garage in Bournemouth ending with Milano. They had carried out the engine rebuild, after the Cam belt had failed, obviously the work hadn’t been completed correctly.
Apparently there is no reason for this Woodruff key to fail, if the Cam pulley and key are both fitted correctly.
It would have been hard to prove liability back to Bournemouth, “ unfortunately “, saying that, the car had been checked by two Alfa dealers, during the period I had this knocking, and I had supplied the symptoms to both, and neither could do a proper diagnostic, whilst the car was still within warranty period.
Anyway she fixed and flying again, now my wallet will require some TLC for a couple of weeks.
May speak to Fair Trading Standards about this one.
Thanks to all