11/16/2025
Here we see a failed thermostat from a CJAA TDI. All too often these stick partially open and go unnoticed. While it may not seem to matter, on these TDIs it's quite crucial to have a properly working thermostat.
When these stick open, it impacts how the engine runs and how the emissions systems function. That combination tends to lead to a drop in fuel economy and shortening the DPF lifespan.
If your temperature gauge doesnt readily rise to the middle (190) and stay there in your TDI, chances are your thermostat is failed partially open.
Contact us and get your TDI back in tip top shape!