2011 Chevy Silverado Duramax 4X4 w/Allison auto, "LIKELY CRACKED HEAD OR HEAD GASKET!" Cylinder compression is pushing water out the coolant tank overflow under a load. This is my personal pickup and it starts and drives very well. You'd never know there was a problem except for the water leaking out the overflow. Tires are 12.50 X 33 General Grabbers w/about 80% tread. The only things that don't work is the backup camera and rear bumper parking sensors. It has a Pioneer Touch screen, blue tooth stereo that works well. Vehicle is very tight and drives straight, quiet and smooth at 75 MPH pulling a 10,000 lb goose-neck trailer. Come look or call with any questions. Service was done every 5,000 miles with synthetic oil. ALL ITEMS ARE SOLD AS IS, WHERE IS without warranty or guarantee. We recommend that you personally inspect each item before bidding. ALL SALES ARE FINAL.