General Motors produces the Yukon. The Yukon comes with a variety of options, such as the XL package, Denali package, or four wheel drive. The 2002 Yukon has had recalls, such as structural, brake and lighting problems.
If the Yukon makes a tapping noise after being started, most likely the engine lifters and valves are "sticking." Worn oil running through an engine will cause deposits and engine "sludge." The deposits cause the lifter passages and valves to stick while moving up and down, which produce the tapping noise.
Add a quart of engine treatment to the Yukon's oil, regardless of the engine size. The engine treatment will help to break down the deposits and sludge. The deposits and sludge will be trapped in the oil filter or removed in the next oil change. The treatment will also lubricate the metal areas to reduce friction and wear.
The tapping noise could also indicate an oil pressure problem in the 2002 Yukon. If the engine has an oil leak it could cause severe damage or even ruin the engine. Consult an authorized GM mechanic if the Yukon has an oil pressure problem.
