Quote Originally Posted by beforethevision View Post
The caps corrode, id take it of and give it a go over with a points file.
I took the cap off yesterday and there were no cracks (looks like new on the inside). However on the inside of some of the lead connections (on the cap) it was filthy. So I cleaned out all of the connections and the car now runs fine without the ignition noise through the radio.

Also since there have been threads on here about how you should only use a genuine cap I thought I would add that the one on the car is an aftermarket looking blue one. While the spare cap looks to be a genuine black one (has Lucas on it). It looks like it has been fitted (locking tab marks) but is perfectly clean and looks new. So I'm guessing it was bought to fix a problem but it wasn't it so it was removed.
Anyway having said all that the aftermarket cap is going fine (13 months at least as was on it when I bought it).