VW Caddy TSI: Boost Leak Symptoms Point to Intake Issue

Had almost the exact same issue with my 2016 VW Golf 1.4 TSI. The symptoms you describe match perfectly, excessive fuel consumption, check engine light, and that characteristic hissing noise during acceleration. After some basic troubleshooting, took it to a workshop where they found a torn vacuum hose connecting to the air intake system. The split was causing an air leak, making the engine run rich to compensate. This explains both the poor fuel economy and the check engine light. The repair was straightforward, they replaced the damaged hose and performed a quick inspection of nearby components. Total cost was 100€ including parts and labor. Engine performance returned to normal immediately, and fuel consumption went back to expected levels. To properly diagnose your specific case, could you share: Any engine error codes youve gotten, Whether the air filter has been recently changed, If you notice any engine misfire symptoms, When the symptoms first appeared, If the sound changes with engine temperature The TSI engines are known for these kinds of intake issues, but the fix is usually simple once the exact location is identified. A proper diagnosis can prevent damage to other components like the turbocharger.

Just had my 132510km service done last month. After checking with a mechanic, my vacuum hose near the intake manifold was indeed torn, matching your diagnosis exactly. Fixed it last week and the engine misfire symptoms disappeared completely. The hissing noise stopped right after the repair and fuel economy returned to normal levels. Most importantly, no more check engine light. Good call on checking the turbocharger connection points too, the mechanic found some minor wear there that could have caused issues later. The error code was P0171 if that helps others with similar symptoms. Total repair cost was 120€.

Really glad to hear you got it sorted out, it matches exactly what happened with my Golf. Those vacuum hoses near the intake manifold are a common weak point on these TSI engines, and leak detection often points right to that area. The P0171 code is definitely a telltale sign. When I had my repair done, they also did a thorough check of the throttle body and surrounding components since everything is connected in the intake system. Making sure all connection points to the turbocharger are tight is crucial for preventing future leaks. Like you, my fuel consumption went back to normal right after the fix. These engines are quite sensitive to air intake issues, and even a small vacuum hose leak can throw everything off. At 132000km, its actually pretty common to see this type of wear. Smart move getting it fixed promptly, leaving intake system leaks unaddressed can lead to more serious issues down the line, especially with turbocharged engines. 120€ is about right for the repair, pretty much what I paid when factoring in the additional inspection work.

Thanks for confirming the vacuum hose issue. The symptoms matched up perfectly with what others suggested, and the P0171 code was definitely the smoking gun. Really appreciate everyone sharing their experiences, saved me a lot of diagnostic time. After getting it fixed last week, the difference is night and day. No more hissing noise from the air intake system, engine misfire completely gone, and fuel economy back to where it should be. The mechanic did a thorough check of all the turbocharger connection points while they were in there, which helped catch some early wear issues before they became problems. Definitely worth the 120€ repair cost considering how much extra fuel I was burning. Posting the error code here should help others track down similar issues. These TSI engines seem pretty sensitive to intake system problems, but at least the fix was straightforward once we pinpointed the location of that torn vacuum hose.