2001 Ford Expedition • V8 AWD Automatic •

What makes my 2001 expedition make bumps and grinding sounds when driving at low speed and quits at higher speed and some times it doesn't do it at all
Jean lee
July 18, 2011.

I see that the vehicle that your vehicle is an all-wheel-drive. This is a system that will engage the 4x4 automatically. The most critical issue facing this system is that all tires MUST be the exact same diameter. Tire combinations that have different diameters feed the computer tiny variations in speed. The computer detects it as slippage, so it needlessly engages the 4x4.

The Ford man
Jul 18, 2011.