Jack Shearer was playing at a family friend's automotive services shop Friday, became thirsty. His grandmother offered him a bottle she found on the floorboard of her husband's truck, thinking it contained water, Merced County Sheriff's Department spokesman Tom MacKenzie said.
The bottle contained a cleaning solution used on aluminum wheels, MacKenzie said.
The grandfather called 911, then drove the boy to a local hospital. He was later transferred to Children's Hospital in Madera and pronounced dead, the Merced Sun-Star reported.
Detectives said they consider the death an accident, and no charges had been filed.
The grandparents' names were not reported.