Boeing's problems do not end with its grounded 737 Max jet, U.S. Rep. John Garamendi told CNBC on Tuesday.

"Going forward, this is not the only issue," the California Democrat said on "The Exchange." "We have a serious problem with Boeing in the military side of it."

Specifically, Garamendi pointed to the KC-46, aerial refueling tankers made by Boeing. The KC-46 experienced two years of delays and ran overbudget by $3 billion before the first one was delivered to the U.S. Air Force in January, but problems persist.

In September, the Air Force determined KC-46s could no longer carry passengers or cargo until issues with floor cargo restraints are resolved.

The KC-46 "doesn't yet work. There are ongoing problems," Garamendi said, before incorrectly saying the plane has been delayed four years. "So we've got a lot of problems with Boeing."

Garamendi, who is member of the House Committee on Transportation and Infrastructure, made his remarks as Boeing CEO Dennis Muilenburg testified on Capitol Hill before the Senate Commerce Committee.

Muilenburg will appear before Garamendi's committee Wednesday as the airplane manufacturer continues to address the fallout from two fatal crashes involving its 737 Max jet.