Flashing CEL with Blue Smoke Points to Failing PCV

Had the same symptoms with my 2015 Audi A4 2.0T. The blue smoke, power loss, and flashing check engine light pointed directly to a failed PCV valve system causing excessive crankcase pressure. The excess pressure forces oil through worn valve seals, creating that blue smoke during acceleration. A clogged or damaged PCV valve cannot properly regulate crankcase ventilation, leading to oil consumption and potential internal engine damage if left untreated. In my case, the entire PCV system needed replacement as the diaphragm was torn and the valve was stuck open. This allowed unmetered air into the intake, causing rough idle and emissions issues. The repair involved replacing the PCV valve, valve cover assembly, and cleaning the intake manifold due to oil contamination. This is a serious issue that should not be postponed. A failing PCV system can cause: Engine oil contamination, Vacuum leak leading to idle problems, Increased emissions, Potential internal engine damage The symptoms you describe match exactly what happens with PCV system failure on these engines. Getting it fixed properly the first time prevents more costly repairs later.

Thanks for sharing your experience with the PCV valve issue. Seems our symptoms were identical. My Audi Q5 is also running perfectly now after the fix, with no more smoke or power issues. The idle is smooth and ventilation system works as intended. Was wondering about your total repair costs? In my case, there was also a small oil leak they discovered during the maintenance that needed attention. Would be good to compare if the pricing was similar and if you had any other problems show up since the repair?

Thanks for asking about the repair costs. My PCV valve malfunction was completely resolved after the fix, paying 360 Euro for parts and labor. The crankcase ventilation system has worked flawlessly since the repair, with no smoke or emissions issues returning. The maintenance fixed all the original symptoms, the blue smoke disappeared, power was fully restored, and the engine runs smoothly at all speeds. No additional problems have emerged in the months following the repair. Unlike your case, I didnt have any oil leaks to deal with, so my total was likely lower than what you paid. The PCV system failure was caught early enough to prevent any secondary issues from developing. A properly functioning PCV system is crucial for preventing excess pressure buildup and maintaining proper engine operation. Regular inspection of these components during routine maintenance can help catch potential issues before they cause more extensive damage.

Thanks everyone for the helpful replies. I finally got the repairs done last week and wanted to share my experience. The mechanic confirmed the PCV valve malfunction and found a minor oil leak from the valve cover gasket. Total repair came to 580 Euro including parts and labor. The crankcase pressure issue was causing oil to seep through worn seals, creating that blue smoke during acceleration. They replaced the complete PCV system, valve cover gasket, and cleaned the intake to remove oil residue. After maintenance, the engine runs perfectly, no more smoke or power loss. The check engine light is gone and acceleration is smooth again. Regular maintenance checks could have caught this earlier, but at least the repair prevented any serious engine damage. Really glad I got this fixed properly instead of trying cheaper temporary solutions. The symptoms matched exactly what others described with PCV system failures. For anyone seeing similar issues, dont wait too long to get it checked out.