Would this radiator cap be useful or is it simply worthless??? I am wanting to keep an eye on the temp to make sure my engine is not overheating and simply relying on the dummy light is frustrating. I had some issues a while back with a faulty thermostat +a faulty wire, so no dummy light=very bad. I do believe it is all fixed but would like another way to keep an eye on things without installing gauges. I thought this might be at least a little helpful but just stumbled across it and have never seen one like it before. Thinking there might be a reason for that and have no idea if this would be a reliable way to keep an eye on the temp.