EGR Valve Failure Causing Major Power Loss in VW Up

Had the exact same symptoms on my 2018 Polo TSI. The rough idle and power loss were major red flags. The EGR valve was completely stuck open, causing excessive exhaust gas recirculation into the intake manifold. The diagnostic showed the valve was jammed with carbon buildup, preventing proper operation. This created a vacuum leak, leading to that distinct hissing sound and uneven engine performance. The smoke was from unburned fuel, and the rough running caused the increased fuel consumption. The repair involved removing and cleaning the EGR valve assembly and passages. This was a serious issue since a faulty EGR can damage the catalytic converter if left unchecked. The check engine light was triggered by the system detecting improper exhaust flow rates. For your Up, these symptoms strongly point to EGR problems. The valve likely needs cleaning or replacement. This isnt a job for basic DIY since it requires proper diagnostic equipment to reset the system and verify proper operation after repair. Worth noting that preventive maintenance like regular oil changes with the correct grade can help prevent EGR issues. Get it checked soon to avoid potential catalytic converter damage.

Thanks for sharing your experience. I had almost identical issues with my Up last year. Your detailed explanation matches what my mechanic found, a clogged EGR valve that was causing a major vacuum leak and rough idle. Your warning about potential catalytic converter damage definitely got my attention since I waited longer than I should have to get it fixed. Could you share what the repair ended up costing you? Also wondering if youve had any related problems since the fix? My car runs fine now but Im keeping a close eye on engine performance and emissions just to be safe.

Thanks for asking about the follow-up. Got the EGR valve fixed last month and it cost 355€ total. The vehicle emissions are now back to normal and the rough idle completely disappeared. Since replacing the defective exhaust gas recirculation valve, the engine runs smoothly with no check engine light warnings. The repair was definitely worth it, fuel consumption dropped back to normal levels and the engine response is much crisper. No related issues have popped up since the fix. The mechanic did a thorough job cleaning out all the carbon deposits in the system while replacing the EGR valve. Just make sure to use quality fuel and stick to regular maintenance schedules to prevent future EGR problems. A proper working recirculation system is crucial for passing emissions tests and maintaining optimal engine performance.

After getting multiple recommendations, I took my Up to an automotive repair specialist. The total repair bill came to 420€, which included replacing the EGR valve and cleaning the entire system. They found extensive carbon buildup causing the vacuum leak and rough idle issues. The repair process took about 4 hours. They thoroughly cleaned the intake manifold and checked the catalytic converter for any damage. Thankfully, catching it early prevented more expensive repairs. Its been three months since the fix, and the difference is remarkable. No more hissing sounds, power loss, or check engine lights. The rough idle is completely gone, and fuel consumption has returned to normal. The smoke issue disappeared immediately after the repair. Just passed the emissions test last week with no problems. Really glad I got it sorted before any permanent damage occurred. Now I stick to a strict maintenance schedule to prevent similar issues from developing.