  Let $G$ be a reductive group defined over an algebraically closed field of
characteristic $0$ such that the Dynkin diagram of $G$ is the disjoint union of
diagrams of types $G_{2}, F_{4}, E_{6}, E_{7}, E_{8}$. We show that the degree
$3$ unramified cohomology of the classifying space of $G$ is trivial. In
particular, combined with articles by Merkurjev \cite{Mer17} and the author
\cite{Baek}, this completes the computations of degree $3$ unramified
cohomology and reductive invariants for all split semisimple groups of a
homogeneous Dynkin type.
