juliussilber47
RS4 PCV Issues Causing Power Loss and Smoke
Summary of the thread
A 2014 RS4 owner experienced power loss, smoke under acceleration, and a check engine light, suspecting the PCV valve system as the cause. Similar issues in an S5 were resolved by replacing the entire PCV system, which restored engine performance and eliminated smoke. The RS4 owner sought advice and, after confirming the diagnosis, had the PCV system replaced, which resolved the symptoms and restored normal engine function. Regular maintenance is now planned to prevent future issues.
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4 comment(s)
juliussilber47 (community.author)
Thanks for sharing your S5 experience. Facing almost identical problems with my Audi RS4 and the crankcase ventilation malfunction symptoms match exactly. After reading about your PCV valve issues and seeing how quickly it can spread to other components, I scheduled an appointment to get it checked right away. My emissions are getting worse by the day and that smoky acceleration is pretty concerning. Did you remember roughly how much the complete fix ended up costing? Also curious if youve had any lingering issues since the repair was done or if it completely solved the ventilation problems?
oliverfox4
Just got the repair bill settled, 360 Euro for the complete crankcase ventilation system fix on my S5. Zero issues since the repair was completed. The smoke under acceleration is completely gone, and emissions are back to normal levels with no more check engine warnings. The fix addressed all ventilation problems and the engine is running smoothly again. Regular maintenance checks show the new PCV valve is functioning exactly as it should, with no oil leak or pressure buildup issues. Definitely worth addressing it promptly before it could affect other engine components. The repair completely resolved the previous problems, no more power loss or rough running. If your RS4 symptoms match what I experienced, getting it fixed now will prevent more expensive repairs down the line.
juliussilber47 (community.author)
I finally got my RS4 fixed last week and wanted to close the loop here. Found a specialized workshop through another owner and the experience was much better than my usual place. The mechanic confirmed the crankcase ventilation diagnosis and found additional wear in connected components. Total repair came to 520 Euro including parts and labor. They replaced the complete PCV system, cleaned the intake, and checked related components. The car runs perfectly now, no more smoke, power is back to normal, and the malfunction indicator is finally off. The idle is smooth again and acceleration is clean with no smoke. Really glad I didnt wait longer as they found the intake was starting to get contaminated. Regular maintenance checks are now scheduled to monitor the ventilation system and prevent future issues. Thanks everyone who shared their experience. Getting a proper diagnosis and repair from a specialist made all the difference.
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AUDI
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RS4
oliverfox4
Running a 2011 S5 with similar symptoms helped identify the failing PCV system as a serious issue that required immediate attention. The check engine light, power loss and smoke indicate a classic case of crankcase pressure problems. The PCV valve failure causes oil to be pulled into the intake, leading to excessive emissions and that characteristic smoke under acceleration. The high crankcase pressure also explains the reduced engine performance, as it disrupts proper air-fuel mixture. In my case, the entire PCV system needed replacement, including the valve, hoses and separator. The rough idle and oil consumption got significantly worse before repair. Left untreated, it started contaminating the intake manifold and affected emissions control systems. The fix involved a complete PCV system overhaul. Post-repair, the engine regained full power, idle smoothed out, and oil consumption returned to normal. This is not a repair to postpone, as it can lead to more expensive damage to other engine components if ignored. Regular PCV maintenance is now part of the service routine to prevent future failures. Worth noting the repair requires specific expertise with these engines to properly diagnose and fix all affected components.