Hello All,

S5 GXL

Idle is Unsteady when warmed up. It sits around 750ish but at times it will bounce, drop and blip itself between 800-600. During this, Loud clicking noise from rear of car, sounds like it's coming from the fuel pump and voltages drops with cluster lights and dash lights fading and dying out...never stalls though always catches itself. Keep in mind I never let the fuel gauge drop below half. I can also rev all the way to red-line with or without load.

Was just gonna change pump first , but I've been told to change the spark plugs and fuel filter first.
I would just write it off as a vacuum leak but that clicking in the rear is throwing me off.

Thanks for the read.

 

Hmm...I understand your challenge here. It's hard to tell if the clicking is the CAUSE or the EFFECT it would seem.

I'd agree on changing the pump first. If that doesn't work try the vacuum leak search. Plugs shouldn't have any relation to the clicking I'd think...unless the clicking is an EFFECT in which case that's a good third step.

Very interested to see what you find as I've never experienced this myself...good luck!