Name that Squeak/Grind!

[tony_ack 0]

Corrado VR6 with 288mm brakes, Koni T/A shocks, -30mm HR springs and 15" Speedlines.

It's developed a squeaking/grinding noise on the NSF lately.

• It's rotational, proportional to vehicle speed rather than engine speed
• It's intermittent. It's nearly always present when cold, sometimes it goes away when warm, sometimes it comes back again.
• Happens when the wheels are under engine load, nearly always goes away when coasting in neutral or with the clutch down (but very rarely doesn't)
• Happens more often when slowing down (either engine braking or with the brakes)
• Happens slightly more often when steering slightly to the right
• Braking makes no difference to the noise (if it's squeaking, it'll carry on squeaking the same under braking, if it's not squeaking, braking doesn't make it squeak)
• Sounds either like thin metal or rubber (my first thought was something fouling on the CV boot, or disc guards)
• Quite loud when it does it (can be heard inside the car with the windows closed).

I've had the wheel off, stripped down the brakes and rebuilt.

• No evidence of rubbing on inner or outer boots
• Brake guard (fairly new) had one bolt broken off and was causing an annoying rattle, so reattached - rattle gone, squeak still there. No evidence of rubbing against the disc (guard still coated in black, no scratches)
• Looks like there has been something catching the caliper at some point, right on the tip. Checked the inside wheel for weights - one was in a position where it may have caught the caliper and had bubbled up with a bit of rust. That said, there was no evidence on the wheel or weight that it had ever been catching, but I still filed down and smoothed the rust on the weights (took a good 1mm off). No different at all to squeak/grind.
• No evidence of tyre rubbing, or anything that could catch it
• Everything else looks fine and secure.

Any ideas what it could be?

 

 

 

 

[fendervg 33]

Wheel bearing?

Also check the bearings on  all the pulleys and the main tensioner for the aux belt.

[_Matt_ 32]

Inner CV joint or even outer?

Inner sounds like this -> https://www.youtube.com/watch?v=AgcMJPURYMA

Outer like this -> https://www.youtube.com/watch?v=qjljUMi-Tc8

 

 

[tonedef 9]

ABS sensor ring slightly bent and catching a sensor, I had this.

[tony_ack 0]

Thanks for the input - ABS ring *is* slightly distorted - it seems to have enough clearance with the wheel off the ground, but it definitely sounds like this might be it.

There's also a little play in the wheel, so the wheel bearing may need replacing too.

[Dox 23]

When I did my nsf wheelbearing the cv was stuck solid inside it, it took a 20t press to budge it. I had to slide the cv off the shaft and press it out, the bearing took Less effort 

[tony_ack 0]

Just an update on this - I investigated the play in the wheel and the hub nut was a little loose! Squeak and grind have now gone.

[Dox 23]

2 hours ago, tony_ack said:

Just an update on this - I investigated the play in the wheel and the hub nut was a little loose! Squeak and grind have now gone.

Keep an eye on it, there’s been several reports in the past of this followed by the end tread shearing off whilst driving  after retightening.

[tony_ack 0]

27 minutes ago, Dox said:

Keep an eye on it, there’s been several reports in the past of this followed by the end tread shearing off whilst driving  after retightening.

Thanks for the heads up  - I think I'm after a new bearing and outer CV joint ultimately