The snow has finally arrived and so I have started playing with the 4WD options.
There is a very noticeable hum under load in Auto, similar to tire noise. It is first detectable around 20kph (~10mph) and rises in pitch with vehicle speed. It rises in volume up to about 60kph (~40mph) and decreases in volume beyond 80kph (~50mph). It virtually disappears completely when coasting under very light throttle, but returns just as loud when engine-braking.
There is a similar hum in 4WD high, but slightly deeper in pitch and much quieter at lower speeds, ie 40 or 50 kph. The pitch of this noise also rises with vehicle speed. The volume is similar to the noise in Auto at 80kph and continues to increase to freeway speed -- 100 kph (65mph) and beyond.
Is this normal or should I be concerned? I've never had one of these automatic 4WD systems before. Some preliminary research on the internet suggests that this may be normal for a chain in the transfer case, but it is somewhat disconcerting.
There is a very noticeable hum under load in Auto, similar to tire noise. It is first detectable around 20kph (~10mph) and rises in pitch with vehicle speed. It rises in volume up to about 60kph (~40mph) and decreases in volume beyond 80kph (~50mph). It virtually disappears completely when coasting under very light throttle, but returns just as loud when engine-braking.
There is a similar hum in 4WD high, but slightly deeper in pitch and much quieter at lower speeds, ie 40 or 50 kph. The pitch of this noise also rises with vehicle speed. The volume is similar to the noise in Auto at 80kph and continues to increase to freeway speed -- 100 kph (65mph) and beyond.
Is this normal or should I be concerned? I've never had one of these automatic 4WD systems before. Some preliminary research on the internet suggests that this may be normal for a chain in the transfer case, but it is somewhat disconcerting.