I have a 2010 Seat Ibiza 1.6 diesel. It will run fine then occasionally engine starts to 'shake' and performance drops off slightly. Numerous mechanics have had a look but to no avail. No warning lights on dash. Just happened again and noticed that the fan wasn't on. Coolant is fine, not using water. Is there maybe a temperature switch failing intermittently to cause this? Temp gauge sits at normal when it happens and no other sign of overheating. Is there maybe another sensor somewhere? It points to being electrical as completely random when it happens. Any suggestions really appreciated. (Code reader does not show any faults)
