VW Up Engine Stalls: Bad Intake Valve Warning Signs

Having experienced similar symptoms on a 2017 VW Polo TSI, the issue was traced to a damaged vacuum hose connection between the brake booster and intake manifold. The air supply problem caused engine stalling and inconsistent idle, matching your symptoms. The throttle body was thoroughly inspected, revealing carbon buildup disrupting proper air valve operation. A complete system diagnosis found multiple vacuum hoses had deteriorated, affecting the overall air intake performance. This turned out to be a serious issue requiring immediate attention, as continued operation risked damaging other engine components. The repair involved: Cleaning the throttle body, Replacing damaged vacuum hoses, Recalibrating the air valve, Testing the entire air intake system The symptoms disappeared completely after fixing these components. For your VW Up, recommend getting the vacuum system tested and inspecting all air intake components. Given the mileage, its likely time for a thorough throttle body service as well. This is a common issue in VW engines around 100k miles, often mistaken for more severe engine problems.

Thanks for sharing that detailed fix. Similar vacuum leak issues showed up on my Up last winter. The check engine light came on out of nowhere and the engine would run really rough especially when cold. Ended up needing the throttle body cleaned plus two cracked vacuum lines replaced near the air intake manifold. Did the repairs fully solve your stalling problems? Would be helpful to know what you paid for the full service, as Im wondering if my mechanic overcharged. Also curious if youve had any other air supply issues pop up since getting it fixed?

Had the Up in the shop last week actually. The stalling completely stopped after they fixed the faulty air valve connection. Turns out there was a damaged hose running from the pump to the valve causing the vacuum leak. Total bill came to 175€ for parts and labor, which included a thorough inspection of the entire air intake system. No air supply problems since the repair. The engine runs smooth now, even during cold starts. The vacuum hoses are all holding up well and the check engine light hasnt returned. Getting it fixed early probably prevented more extensive damage to the intake system. Quick tip: regular inspection of vacuum hoses can catch these issues before they cause serious problems. The mechanic showed me how deteriorated hoses often start failing around the 100k mark on these engines.

Thanks for the advice. Finally got my Up back from the shop yesterday! They found exactly what you described, vacuum leaks and a dirty throttle body causing the idle problems. Total repair came to 190€, which seems fair based on what others paid. The mechanic showed me the old vacuum hoses, they were cracked and causing major air intake issues. They cleaned the throttle body, replaced all the damaged hoses, and reset the check engine light. Car runs perfectly smooth now, especially at idle. Much better experience with this new shop. They took time explaining the air supply system and showed me the worn parts. Really glad I caught these issues before they caused bigger problems. Thanks again for pointing me in the right direction with the vacuum system check.