On an old American car, that could be the sign of your starter going bad. Does this happen when the car is hot only? Then most likely it is the starter, but I am not guru on diagnosis.

What a shame one 1 yr old and already cannot start. Just go to a Tech and use the warranty.

------------------
'89 420 SEL
'90 300 SEL
'68 Olds 88 Convertible
'84 300 SD (sold it)