VW Polo Diesel Cold Start Issues, PTC Heater Fix Guide

Had nearly the same issue with my 2016 VW Golf diesel. As someone with moderate car repair experience, I can confirm PTC heater problems are quite common in these engines. The symptoms matched exactly, rough cold starts, higher fuel consumption, and engine warning light. The HVAC system was also affected, with the temperature control acting up and inconsistent cabin heating. Took it to a workshop where they diagnosed a faulty electric auxiliary heater. The repair involved replacing the complete PTC heater unit and checking the blower motor connections. Total cost was 350€ including parts and labor. The whole job took about 3 hours. Since the fix, cold starts are smooth again and fuel consumption returned to normal. The cabin heats up properly now too. To help further with your case, could you share: Have you checked if cold air is coming through the vents when it should be warm? What error code is stored exactly? Has your fuel consumption increased by a specific percentage? Did you notice any changes in cabin heating performance?

Thanks for sharing those details about the Golf repair. Just had my 71730km service done last week and noticed similar issues with cold starts right after. The check engine light shows P0668 code in my case. Definitely seeing issues with the heating element, as the cabin takes much longer to warm up than before. The cold air problem is most noticeable during the first 10 minutes of driving. Fuel consumption has jumped about 15% over the past month. Had someone check the temperature control system and they confirmed the HVAC system is affected. That 350€ repair cost sounds reasonable if it solves both the engine and heater repair issues. Did your workshop mention if this is a common wear item at this mileage?

Thanks for those additional details. Yes, my Golf had similar timing, issues started showing up right around the 70,000km mark. The P0668 code is exactly what my car displayed too, relating to the PCM monitoring circuit for the PTC heater system. The 15% fuel consumption increase matches what I experienced. The extra fuel burn happens because the engine management system compensates for the faulty heating element by adjusting the fuel mixture during cold starts. When the workshop did my heater repair, they mentioned these PTC heater units typically need attention between 65,000-80,000km on our engine type. The heating system deteriorates gradually, which explains why you noticed the cabin heating performance decline over time. Our repair bills were similar because both cars use nearly identical heating system components. One tip, while they have the heating element out, have them check the connector pins and wiring harness. Mine had some corrosion that could have caused issues later. The fix completely resolved both the cold start roughness and the cabin heating problems. Been running smoothly for 25,000km since the repair with no heating-related issues.

Thanks, really helpful details. Looks like I'll need to book it in soon, especially since my mileage matches when these issues typically show up. Just called a local workshop specializing in VW repairs. They quoted 380€ for the complete job including the heating element replacement and electrical checks. Going to schedule it for next week since the cold air problem is getting worse and I want to avoid any potential damage from the rough cold starts. Good tip about checking the connectors and wiring, I'll make sure to mention that when I take it in. The extra fuel consumption is definitely noticeable in my monthly costs, so fixing the heater repair should pay for itself through better efficiency. Will update once the work is done, but sounds like this is a straightforward fix that should sort both the engine performance and cabin heating issues.