In recent days my 2004 s-type has developed a rather loud noise once I reach a speed of 80 km/hr. At the same time the outside temperature increases to about 29 degrees Celsius. The noise increases as the speed increases, as does the temperature. At a speed of 120 km/hr the car sounds like the exhaust has gone and there is a very tiny vibration in the steering wheel. The outside temperature rises to 47 degrees Celsius. At 140 km/hr the vibration is more noticeable but not excessive. The outside temperature rises to 51 degrees Celsius. If I return to a city speed of 60 km/hr, the noise dissipates and the outside temperature returns to 25ish. Currently, I'm on Pirelli snow tires that make a similar noise on drive pavement and the outside temperature is about 16 degrees Celsius. Snows are coming off this weekend.

Has anyone had a similar problem or know of a fix?

 

If by outside temp you mean as displayed on the climate panel then the sensor is at the front of the car - look up under the center front. At least is SHOULD be there but given the rise you see maybe it's loose and resting - being blown, really - on one of the radiators (there are several). Or something.

The noise... don't know... wheel bearing, maybe?

I would NOT drive it at that speed (and preferably not at any speed) until you are sure it's safe to do so.

 

I can't find any kind of sensor at the front. Can you describe what it looks like?

Thanks