We have classified the 4 complaints from 2002 GMC Yukon about ENGINE AND ENGINE COOLING into the following categories.
While driving 45 mph vehicle lost power. without warning. dealer could not duplicate the problem. *ak
While driving a loud knocking noise was heard from the front. consumer was able to drive the vehicle to dealer for inspection, and mechanic determined that a carbon build up on the piston caused the knocking. *ak
Defective engine (pistons knocking in cylinders, as documented by dealer) on 2002 yukon slt; 19,500 miles
2002 yukon - brief engine knock when vehilce is started. also, has an exhaust noise/rattle at approximately 40-42 mph, 1000=1300 rpms. noises started at approximately 2000 miles.
When starting the vehicle, there is a very audible engine knock. it seems to go away after about 30 seconds or so. doesn't get beter nor does it get worse but it is very noticeable.*ak