Diagnostic guidance. Suggested checks and possible repairs are separate from the owner's reported results.
Have the key and lock operation inspected before authorizing replacement parts. Tell the repairer whether a spare key behaves differently, if that information is available.
Source: Original question and visible replies. Owner reports and other participants' experiences are distinguished. Next steps are editorial guidance for obtaining diagnosis or clarifying the reported findings; they are not a verified repair procedure or an independently confirmed component diagnosis.
Key wont turn 1997 Malibu
The owner of a 1997 Malibu reported that the ignition key would no longer turn in either direction.
Reported outcome: No diagnosis or successful repair was reported by the original owner.
A participant with a 2000 Malibu described manipulating their key. That account does not establish the condition of this vehicle's key or lock.
