RS5 Crankcase Valve Failure Causing Power Loss & Smoke

Had the same malfunction on my 2018 Audi S5 3.0T. The PCV valve failure caused blue-gray smoke during acceleration and significant power loss. The check engine light came on due to increased emissions and irregular pressure readings. The repair involved replacing the complete PCV assembly since the valve was integrated into the valve cover. The smoke issue worsened over time because the failing PCV allowed oil to enter the intake system. This created carbon buildup on intake valves and reduced engine performance. This is a serious issue that requires immediate attention. Continued driving risks damaging other engine components and can lead to increased oil consumption. The repair took about 6 hours at the shop. They also cleaned the intake manifold to remove oil residue. The symptoms match perfectly with PCV system failure. Getting it fixed quickly prevents further engine damage and restores proper crankcase ventilation. Would suggest having it diagnosed and repaired at a shop that specializes in Audi engines, as proper diagnostic equipment is needed to verify the issue.

Thanks for sharing your experience. My car started having almost identical issues with smoke and idle problems. Had it diagnosed and fixed last month, definitely was the PCV system causing the malfunction. Would you mind sharing what the total repair cost was? My ventilation valve replacement plus labor came to 890 Euro, but wondering if thats in line with what others paid. Also curious if youve had any other related issues pop up since the repair?

Thanks for asking about the costs. I got my crankcase ventilation system fixed about 3 months ago and paid 360 Euro total, including parts and labor. This was significantly less than your repair cost, but prices can vary based on parts availability and labor rates. The good news is that since fixing the malfunction, my S5 has been running perfectly. No more smoke issues during acceleration, power is back to normal, and emissions are where they should be. The idle is smooth again too, its like having a new car. The initial diagnosis was spot on, and replacing the valve completely resolved the problem. No related issues have appeared since the repair. Make sure to keep an eye on oil levels during the first few thousand kilometers after the fix, but otherwise you should be good to go.

Wanted to update everyone on how this turned out. Took the car to an Audi specialist last week who confirmed the PCV system malfunction. The ventilation valve was completely worn, causing oil to leak into places it shouldnt. The repair process took about 5 hours. They replaced the entire PCV assembly and cleaned out the accumulated oil residue. Total cost came to 890 Euro, which seems a bit high compared to others, but the smoke issue is completely gone now. Engine power is back to normal and no more check engine light. The mechanic showed me the old valve, it was pretty badly deteriorated. Guess its better to pay more for a proper fix than risk bigger engine problems down the line. Running perfectly now with no ventilation issues or smoke during acceleration. Definitely worth getting it sorted quickly when these symptoms show up.