Lexus ES Temperature Gauge Issue

I also drive a Lexus ES, although a different year, and I experienced similar symptoms not too long ago. Are you certain that the cooling grille is the primary cause? Before jumping to conclusions about the grille, have you considered checking the coolant level or inspecting the thermostat?

Coolant level is fine, I checked that first thing. Thermostat seems okay too, though I haven't taken it apart. But seriously, a grille issue causing all these symptoms? How could that even work?

While a partially blocked grille may not be the sole culprit, it's plausible it could contribute to the issues you're encountering. Think of it like this: a blocked grille is like trying to breathe through a straw while running a marathon. The engine struggles to cool effectively, leading to temperature fluctuations and potentially triggering the check engine light. However, considering the severity of your symptoms, I would advise consulting a qualified mechanic for a comprehensive diagnosis. There may be other underlying factors at play that require professional attention.

Thanks, I appreciate the input. Turns out it was just a faulty fuse for the coolant temp sensor. Replaced it for 52€ and now everything is back to normal. Crazy how one little fuse can cause so much trouble!