BELT ROUTING FOR 2005 BUICK LACROSSE 3.8 MOTOR

It is along the belt route. It is a 3" diameter pulley about mid engine .It is on a lever about 4" long has a big bolt head and the lever has about 2" of clearance to move back and forth. You release it by turning the counterclockwise.
Mike

basically the grooves go on the grooved pulleys and the back of the belt runs on the idler pulleys
there are about 3 different configurations for belts as they run nor power steering / power steering, ac and no ac systems so to get a picture you will have to comment on what is running and the motor size

It may be a good primer to follow this YT video for a GM V6 motor. CHANGING SPARK PLUGS AND WIRES GM 3 1 3 4 V6

Here is a link that will show you how to
Tail Light Change 2005 2009 Buick LaCrosse 2006 Buick LaCrosse CX 3 8L V6

Replace the belt, never repair them or spray anything into them.

Please follow this link to find the 2006 Buick Lacrosse's belt diagram: https://galvinconanstuart.blogspot.com/2019/04/2005-buick-lacrosse-belt-diagram.html

It should be under the hood on a placard. If not someone has removed it. In that case here it is.

If there is no decal under your hood somewhere, you can usually get them by wrapping the belt, first, around the crank pulley, and then work your way around, putting flat sides to flat pulleys, and ribs to ribs. There may be a couple of different ways to go, but you'll figure it out.

if you buy your belt from auto zone the routing is on the back of package

For a v-6 3.6L follow this link...
http://www.gates.com/common/part_locator/view_diagram.cfm?id=S7031
For a v-6 3.8L follow this link...
http://www.gates.com/common/part_locator/view_diagram.cfm?id=S6024