front end knock

[tonym911]

The '98 1.6 has been sitting quietly for the last four weeks or so, got in it this morning and noticed a speed-related knock which sounds like it's from the front end, at walking speed its knock knock knock, when you speed up so does the knocking till you reach 30 or so when the knock frequency makes it 'go away' . It also seems less pronounced on right-hand bends, ie when there's less weight on the front offside wheel, which makes me think it might be coming from there. Tried to replicate the noise in reverse but it doesn't seem to happen then.
Is it a wheel bearing? Can they just go when the car's been stood doing nothing?
Should perhaps also mention that it had new brake pads all round within the last six months but I suspect one of the discs is warped as there's that low-frequency on-off feeling when you're braking to a halt.

[MX-5 Lazza]

Is there a stone stuck in the tyre tread?

[tonym911]

Sadly not

[Munter]

Brake pad floating around a bit?

[tonym911]

Hmm… dunno. It did get a new caliper as part of its brake overhaul a few months back, the old one was peeing fluid.

[rovermorris999]

Very likely to be an anti-roll bar link.

[MX-5 Lazza]

rovermorris999 said:

Very likely to be an anti-roll bar link.

Not so sure about that. They don't rotate with the wheel.

Could just be some rust on the disc catching the pad. If so it would go away after a few miles.

[tonym911]

Hope so - though would that make a knocking noise?

[rovermorris999]

MX-5 Lazza said:

Not so sure about that. They don't rotate with the wheel.

Ah, didn't notice the speed related bit in the OP's post.

[MX-5 Lazza]

tonym911 said:

Hope so - though would that make a knocking noise?

Probably not but without being able to hear it myself it's hard to say.

[tonym911]

It's a bit like someone lightly tapping a table with a fairly small hammer wrapped in a sock.

[MX-5 Lazza]

Did you get anywhere with this?

[tonym911]

No. Our other car is in the garage having expensive work done so the Mazda wil have to wait a bit for diagnosis! Thanks for asking and help thus far though, it's good to know you're out there.

[MX-5 Lazza]

Something to try: Jack up each corner and turn the wheel to see if you can feel/hear the knock and possibly identift where it's coming from. To do rear try it with one wheel up first then with both wheels up as if the noise comes from the dif it will help us with the analysis.

[tonym911]

Thanks mon, I'll give that a go at the weekend.

[madmover]

Someone i know whos a local mx5 owner to me had a similar problem and his turned out to be a ball joint i believe...

[tonym911]

Hmm yes I was wondering about that.

[mycool]

Might be an obvious one but are the wheel nuts tight?

My dad was once doing some driving at Millbrook Proving Ground on a Vauxhall launch day and one of the press photographers had taken a wheel off to get a photo of the big brakes on the sporty model and only replaced the nuts finger tight. Dad did 2 laps of the highspeed bowl and noted knocking as he got up to speed and again as he slowed down - a check by the technician after revealed the loose wheel nuts - very lucky boy!

[tonym911]

mycool said:

Might be an obvious one but are the wheel nuts tight?

My dad was once doing some driving at Millbrook Proving Ground on a Vauxhall launch day and one of the press photographers had taken a wheel off to get a photo of the big brakes on the sporty model and only replaced the nuts finger tight. Dad did 2 laps of the highspeed bowl and noted knocking as he got up to speed and again as he slowed down - a check by the technician after revealed the loose wheel nuts - very lucky boy!

Good call, another point to check, been running around too much recently in the other car to sort this. Maybe I should be worrying a bit more about letting the missis drive the Mazda to school and back though...