For the last 3-4 weeks I've had very poor FM reception.
The audio is fine when the engine is off, and at its worst when the engine is at idle. Raising the revs gives a cleaner sound out of the radio.
The interference is all cracks / hiss / pops, and seems to bear no relation to either engine or road speed.
The car is a 2001 Skodas Octavia and the engine is the 1.9 TDI 110, which uses a Bosch VP37 injector pump - not one of the more recent PD or even later CR diesels.
Headunit is an aftermarket Sony XAV-601BT - but it has been in the car for well over a year without these issues.
Any clues as to where to look first?
Thanks!