Fox VANOS Failure Causing Power Loss and Fuel Waste

Had the same problem with a 2005 Rabbit. The check engine light came on along with low power symptoms, especially during acceleration. Started with an engine misfire that got worse over time. Turned out the VANOS solenoid was failing, which caused irregular fuel consumption and timing issues. The timing chain noise during cold starts was a clear indicator something was wrong with the variable valve timing system. The repair involved replacing both VANOS solenoids and cleaning the oil passages. It was a serious issue that needed immediate attention since a failing VANOS system can lead to complete engine failure if left untreated. The diagnostic process showed: Failed electrical tests on VANOS solenoids, Contaminated oil in the VANOS system, Irregular camshaft timing, Increased engine load readings Important to have this checked soon, as waiting too long can cause the timing chain to skip teeth or break. Recommend getting the solenoids tested first before replacing any major components.

Had similar VANOS solenoid problems on my VW last year. The check engine light kept coming on and the engine felt sluggish. The inlet camshaft timing was completely off, causing poor performance and that rattling noise you mentioned. Fixed mine by replacing both solenoids and doing a thorough oil system cleaning to remove oil sludge buildup. Car runs perfectly now with proper power and normal fuel consumption. How much did you end up paying for the repair? Did you notice any other issues pop up afterward? Just want to compare if the costs were similar and make sure nothing else needs attention.

After taking it to the mechanic, they diagnosed the inlet VANOS mechanics as faulty. The issue was specifically traced to a defective camshaft solenoid valve which was causing the low power symptoms. Total repair cost came to 250€, which covered both parts and labor. Since fixing it, the engine performance has returned to normal with no other issues appearing. The timing chain noise disappeared completely and fuel consumption is back to standard levels. The repair also eliminated the engine misfire problems I was experiencing before. Worth noting that during the repair they found some oil sludge buildup in the VANOS system, but cleaning that was included in the total cost. The mechanic confirmed that catching this early prevented more extensive damage to the engine timing components. No additional problems have surfaced in the months since the repair, and the engine is running smoothly with proper power delivery during acceleration. The check engine light hasn't returned either.

Thanks for the insights. Finally took my Fox to the mechanic last week. The inlet camshaft position sensor was reading incorrectly due to a failing VANOS solenoid. Total repair ended up costing 380€, bit more than yours but they also replaced some worn gaskets they found during inspection. The timing chain noise is gone now and the engine runs much smoother. Fuel economy is back to normal too. No more check engine light or power loss during acceleration. Glad I got it fixed before any serious damage occurred. The mechanic showed me the old solenoid, it was completely gunked up with oil deposits. They cleaned out the whole VANOS system while doing the repair. Good preventive maintenance to avoid future engine misfire issues. Overall satisfied with the fix even though it cost more than expected. Better than risking major engine damage by waiting too long.