Car started to run rough(not missing) all of a sudden one day, makes it fairly undriveable. Car had an exhaust leak before and after roughness started.
Mechanic(VW specialist) checked everything he could think of, plugs, injectors, boost and vac leaks, coils, compression, maf, throttle body adaption, cam timing, fuel trims, no codes, couldn't find anything.
I've replaced PCV, (one near turbo), cleaned maf, air intake temp sensor, no change. Fixed exhaust today, replaced purge valve(it was broken and repaired with epoxy, I broke it some more checking it), tomorrow is fuel filter, coolant temp sensor, bleeder (pcv under intake manifold) valve.
Yet to start the car after todays work so I don't know if it is fixed yet.
I keep thinking cam timing but that should give a code, or fuel metering.
Something has decided not to work all of a sudden, causing the roughness.
Anyone had anything like this?