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I have replaced the front discs and pads on my 2003 HDI estate, since fitting the new parts i am getting an intermittent grinding noise which sounds like there is a rough patch on the disc or a crack but both discs are in good condition.

It doesnt happen all the time but when it does the the sound is definitely rotational as it changes with the speed also I can feel something through the pedal.

Any Ideas anyone

I expect someone with much more knowledge than I will be along soon,
but that sounds rather like the ABS kicking in.

2 weeks late.
Split ABS reluctor ring can cause spurious ABS operation which is a vibration that you can feel through the pedal.
Easy to check, get a torch put steering on full lock and roll car forward checking the toothed ring on the CV joint, they crack & split wide open.
Not sure if it happens on the rears as well.

Even later reply from me, I have been away most of October.

Thanks for your input piglet I have checked on you tube after reading your post and there is a how to for checking and cleaning the front ABS sensors.
I have taken your advice and visually checked the reluctor rings on the front and cannot see any cracks, next job will be to remove the sensors and clean them as shown on you tube, I will check the fronts first hopefully at the weekend and see if I can find anything.

I had the same experience once after replacing the brake pads of the rear wheels of my wife's car.

Turned out that in the hurry i had put one of the brake pads in the wrong way round (the painted side toward the disc).

I think I may have got to the bottom of it at last (brake pads all in correct way round frog)

After reading piglets reply I checked the reluctor rings on the front brakes both were good, found a how to on youtube for cleaning the front sensors so did that as they were both dirty but didnt solve the problem.
So moved to the back took the disc off nearside to find the hand brake shoe retaining springs and pins had broke free and were tangled up on the abs sensor bending it, removed all the debris and replaced the retaining pins with nuts and bolts (youtube fix again) and carefully bent the sensor pin back, big improvement but still not perfect so maybe the sensor pin needs more adjustment but I havent checked the offside yet there maybe a similar problem there

cliffk wrote:So moved to the back took the disc off nearside to find the hand brake shoe retaining springs and pins had broke free and were tangled up on the abs sensor bending it

Ah yes, i had exactly the same. The handbrake shoe retaining pins come out after so many years and start grinding themselves through the drum until they reach a point where the stick on to: the magnetic ABS sensor. First time it happened I was driving quite slowly over a speed bump. My car seemed to jump a few inches up, then the grinding noise started and the ABS warning light went on after a while.

I removed the caliper and disc/drum to find that the pin and spring had let go of the heat shield and had made its way to the ABS sensor. Fixed it by simply removing the pin (and spring) altogether, they seem completely unnecessary. Luckily the ABS sensor was undamaged and the ABS warning light went off.

A few months later the other side went exactly the same.

A terrible design flaw!