A8 3.0TDI uneven idle hot and cold.
Discussion
Car is a 2009 A8 3.0TDI with 68k miles.
It started occasionally having a lumpy or uneven idle from cold , but would clear in a few seconds, I assumed glow-plugs or dirty injector, tried new Beru glow-plugs and a fuel treatment, but the problem has now developed into a constant uneven idle and up to about 1200rpm.
Car drives fine on the move, feels as though it has full performance, is no worse on fuel, and is not smoky, (smoke may be masked by DPF).
No warnings on dash.
Initial scan with VCDS showed nothing in fault that looked like a culprit, the injectors all measure same resistance and no fault to ground. Need to check the flow rates per stroke with VCDS.
Swirl flaps control rods appear to be behaving as normal.
Its a pain, trying to decide who to trust to diagnose.
Anyone want to offer an opinion on likely causes?
It started occasionally having a lumpy or uneven idle from cold , but would clear in a few seconds, I assumed glow-plugs or dirty injector, tried new Beru glow-plugs and a fuel treatment, but the problem has now developed into a constant uneven idle and up to about 1200rpm.
Car drives fine on the move, feels as though it has full performance, is no worse on fuel, and is not smoky, (smoke may be masked by DPF).
No warnings on dash.
Initial scan with VCDS showed nothing in fault that looked like a culprit, the injectors all measure same resistance and no fault to ground. Need to check the flow rates per stroke with VCDS.
Swirl flaps control rods appear to be behaving as normal.
Its a pain, trying to decide who to trust to diagnose.
Anyone want to offer an opinion on likely causes?
Gassing Station | Audi, Seat, Skoda & VW | Top of Page | What's New | My Stuff