The 3.5 was nicknamed "shortstar". It was NEVER officially called it nor a badge designated for it. Also it was NEVER used in any Cadillac during it's time period let alone a sigma body STS.framedforlife said:unless he bought an olds with the shortstar.
I second the use of Techron and/or the use of "top tier" gasoline; a good throttle body cleaning now and again (along with tight plenum bolts) is super easy to do and keeps the N* smooth and responsive.Every oil change I'll run a bottle of chevron techron fuel additive in my gas. Seemed to smooth out the idle in my 03 STS so I figure it's doing something so I use it in all my cars.