Audi A2 VANOS Fault Causing High Fuel Consumption

Had the same symptoms with my 2008 Audi A3 2.0T. The check engine light came on along with engine misfire during acceleration. The problem turned out to be a VANOS failure caused by a defective inlet camshaft solenoid. The variable timing system was not functioning properly, causing poor fuel economy and rough idle. The diagnostic showed incorrect timing values and low voltage to the VANOS solenoid. After replacing both the solenoid and its wiring harness, the system regained proper functionality. This is a serious issue that needs immediate attention, as continued driving can lead to further engine damage and even more costly repairs. The repair requires specialized diagnostic equipment to properly test the variable timing system and verify the fix. Signs that confirmed it was VANOS related: Increased fuel consumption, Rough idle, Power loss during acceleration, Error codes related to camshaft timing After repair, fuel economy returned to normal and the engine ran smoothly again. Regular oil changes with the correct oil specification help prevent future VANOS issues.

Thanks for sharing your experience with the VANOS failure. Those symptoms match exactly what I am seeing with my A2, especially the low power issues during acceleration. I got it looked at yesterday and the mechanic also mentioned the solenoid might be the culprit. Do you remember roughly how much you ended up paying for the complete repair? Also curious if you had any related issues pop up since getting it fixed? The check engine light in mine started flickering before staying on permanently, which seems similar to what you described. Just want to make sure I am prepared for the repair costs.

Thanks for asking about the repair costs. Since fixing the inlet VANOS mechanics in my A3, all issues have completely cleared up. The repair bill came to 250 Euro for replacing the faulty camshaft solenoid valve and resolving the power supply problem. The flickering check engine light you mentioned is exactly what I experienced before getting it fixed. The repair completely resolved the low power problems and restored normal acceleration. No related problems have occurred in the time since. Regular maintenance has kept everything running smoothly, just make sure to prevent oil sludge buildup with consistent oil changes, as this can affect the timing chain and VANOS system over time. The fix was definitely worth it considering how much better the car runs now and the fuel savings from restored efficiency.

Thanks everyone for the helpful feedback. Wanted to give a quick update on how my repair went. Took the car to a different shop this time that specializes in Audi engines. The mechanic confirmed it was indeed a VANOS issue caused by a faulty inlet camshaft solenoid. The timing chain also showed some wear, so I had them replace both components while they were in there to prevent future problems. Total came to 580 Euro including parts and labor. The engine runs perfectly now, no more low power during acceleration and fuel consumption is back to normal. No oil sludge buildup was found, which was a relief. They did recommend staying on top of oil changes every 10000 km to keep the VANOS system healthy. Really glad I got this sorted before any engine misfire damage could occur. The car feels like new again and the check engine light has stayed off. Definitely worth the investment compared to risking more extensive repairs later.