OT: Car making spurious noise

brakes pads down to the squeelers ?

I had a very similar sound with my Ford Fusion a few days ago. A sort of rubbing noise that came and went. I also suspected a sticking brake pad. Soon after it started, someone behind me started flashing their lights vigorously and I pulled into a convenient little garage forecourt and the 'flasher' said the car was pouring smoke from underneath with a strong smell of burnt rubber. Turned out that the front o/s suspension compression spring was broken, and the stub was rubbing against the tyre and gradually cutting its way into the side wall. Very much further and it would have cut right through with goodness knows what consequence; I was very lucky.

Clutch in use?

Coasting as in neutral cluch up? Or coasting as in in gear clutch down? Or coasting as in in gear clutch up no accelorator?

If you drove at 30 mph, and just stopped the car on the brakes the discs would be too hot to touch. Assume: car weights 1000 kg, discs weigh 2 kg, specific heat capacity of mild steel 0.5 J/g/deg C.

Kinetic energy = 1/2 * m * v^2 = 1/2 * 1000 * 13.4^2 = 90,000 joules

Could be that your are getting onto the squealers in the brake pads. Occurs when braking.

Or it might be the clutch release bearing, occurs when the clutch is depressed, may only occur at one position in the travel.

Or in might be a drive belt slipping, occurs when the load changes on that drive belt, could be from air con compressor, lights coming on, heated screen(s).

Interesting though no-one has flashed me yet!

I'll check the inside of my tyres tomorrow in the daylight.

Doesn't seem dependend on clutch or overrun.

Must say I've not tried knocking it into neutral.

Interesting, I'll try a stop with handbrake and gears only next time. How quickly do the disks cool back down to ambient?

I've tried that in the driveway - everything on but couldn't get it to perform and it doesn't sound like the screech of a drive belt slipping which is usually very distinctive.

I'd hope that brake pad issues would have been mentioned at the last service/MOT 6 months ago - I don't do a lot of miles, maybe 4,000 since.

However mechanic did point out that the disks were showing signs of corrosion caused by the car sitting outside for days on end in the rain and trapping water between the pads and the disk. He wasn't amused when I said I'd spray some WD40 on them!!

water pump on the way out alternator about to go bang the list is endless with fords. It seems almost everything is capable of groaning!

According to a friend of mine anyway. Brian

discs

Stationary quite a while, if you stop and hop out they won't have cooled much. Driving a lot faster assuming ventilated discs (I think most are these days). From hot enough to fade to becoming reliable again, ie not fading again as you use them, a best part of five minutes at 50 mph with no use...

I've had binding brakes a couple of times normaly rears, it has to be really bad for you to notice and the only noise I've had is a fairly quiet high pitched squeak, Had a front bind once, noticed that, it started to struggle on a hill, pulled over, got out and there was a nice cherry red glow from the disc (it was at night). Had to complete the journey in ten mile sections with 20 minute "rests"...

I noticed a binding front disc not far into a long journey - just slackening the bleed nipple and retightening made it go away.