I am noob, so if there is a thread that allready discuss this issue, please provide a link.
I have an 03 Passat. I am hearing a clicking noise to the lower left of the stearing column (fuse/relay box area). I have noticed the clicking at several times. When I start the car, I can hear it in correlation with the Supplemental Air Pump. Once the car warms up, I don't hear the noise when at an idle. But I will hear the noise while I am driving. It is not consistent and I do not always hear it while driving.
I have a theory that it may be related to the Fuel Pump Relay (as I have read that the relay is located in this area). I am going to test if it happens when I have a ¼ tank of gas as opposed to a full tank.
Maybe someone here can tell me what controls are the SAP relay and the Fuel Pump relay are connected to. Any ideas would be greatly apprciated.