Had the same noise and was also the rear hub nut, posted it on here ages ago :)

dipster

hi, just a quick comment, i bought br series off the group buy and i,m well impressed with the ride and particullarly the composure over bumps under braking which was the downfall of my previous setup. i do get the odd spring twang or whatever but was expecting that with solid top mounts. totally exceded my expectations thanks Bren, Jason:thumb:

got my bc coilovers fitted by olly at roger clark motorsport but i almost didnt,because of reading all the members complaining about noises and knocking suspension i asumed it was shody workmanship as i have been running coilovers on my other cars for the last 13 years without a problem,just a firmer ride which is the trade off if you are looking to upgrade the performance of your suspension.but to my suprise they were perfect compliant and the ride quality had to be one of the most smoothest rides from coilovers that i have ever had and thats with pillow ball top mounts front and rear.credit is due thanks bren for setting up the group buy im glad that my wife got them for me now.

here is a fix for knocking guys

https://www.scoobynet.com/suspension...-1-newage.html

Bren - and the guys/gals at Apex. I am so so pleased that someone local to me seems able to fix my BC coilovers.

Car is a P1, so classic shape.
Mine are about 2 months old, and done about 2K. They have knocked on the N/S/R initially then the O/S/R too, exactly the same symptoms as some have described from reading this thread.

It seems that the solution is the top mounts - All I can say is that I am bloody pleased there is a fix for this, my local garage has just said there is nothing wrong with them.

I am again sooo pleased you are close. Will be in touch during the week.