VW Taigo Overheating Traced to Bypass Valve Issues

As someone with some experience working on VWs, I had a very similar issue with my 2020 VW T-Cross. The engine overheating symptoms matched exactly what you are describing. In my case, the root cause was actually connected to a previous repair where coolant had been changed. The technician had not properly bled the cooling system, which created air pockets leading to inconsistent coolant flow and false temperature readings. The bypass valve was initially suspected, but it turned out to be functioning correctly. The fix required no parts and therefore no cost, just a proper bleeding of the cooling system. The workshop acknowledged their oversight from the previous service and corrected it under warranty. To better assist with your specific case, could you share: When was your last coolant service performed? Are you noticing any coolant leaks under the vehicle? Does the temperature fluctuate or remain consistently high? Which specific error codes are you getting? The correlation between power loss and engine overheating can point to various underlying issues in modern VW engines. Proper diagnosis is crucial to avoid unnecessary parts replacement. Consider getting a cooling system pressure test done, this can reveal if there are any leaks in the system that might be contributing to the problem.

Last service was done 2 weeks ago at 29000km. After reviewing the responses, I had the cooling system pressure tested as suggested. The test revealed no leaks in the system, and all hoses appear intact. However, I noticed the temperature fluctuates rather than staying consistently high, which seems different from the air pocket issue mentioned. The error code is P0217. The coolant leak check was particularly helpful to rule out immediate issues. Currently monitoring if the engine stalling occurs in conjunction with the temperature spikes, as this could indicate a connection to the air intake or vacuum system.

Thanks for providing those additional details, especially about the P0217 code and temperature fluctuation pattern. This differs from my T-Cross case where temperatures remained consistently elevated. The fluctuating temperatures combined with P0217 could indicate an issue with the thermostat or cooling fan control module. On my VW, I initially experienced similar erratic temperature behavior before the full overheating problem developed. Since your recent service predates these issues, it would be worth checking if any work was done near the air intake or vacuum system components. In VW engines, a compromised vacuum system can actually contribute to irregular cooling performance and power loss. A few things to monitor: Does power loss occur simultaneously with temperature spikes, Is the cooling fan running at appropriate speeds, Are there any changes in engine sound during temperature fluctuations Given these symptoms differ from my previous air pocket experience, having a diagnostic scan focused specifically on the cooling system sensors might reveal more. The bypass valve may still be involved, but these signs suggest investigating the thermostat and fan control first.

Thanks for all the input. Going to have the shop focus on checking the thermostat and fan control module first, since the symptoms align more with those potential issues. The temperature spikes do seem to match with occasional power loss, especially during acceleration. The cooling fan appears to run constantly rather than cycling normally, which could point to a control module problem. Will monitor the vacuum system for any unusual sounds during the temperature changes, as mentioned. Really helped avoid going straight to a bypass valve replacement without proper diagnosis. Will update once the shop completes their inspection of the thermostat and cooling system sensors. The error code P0217 combined with the fluctuating temperatures rather than constant overheating seems to be the key difference in diagnosing this specific problem.