more than likely a bad oil sending unit but you need to get it checked out to make sure.
A 1974 Chevy Impala frame would work
ON the 2006 impala that whining noise is actually the electronics when you accelerate. Its more or less electronic pulses/signals My 06 Impala is the same.
Thermostat.
It could be a weak battery or a bad ignition coil.
Check with your local Chevy dealer on that.
Low fuel pressure
no
It could be that you need coolant or it's low.
If someone installed a diesel fuel tank into a 1996 Chevy Impala SS, it could cause the spark plugs to catch on fire and further damage would occur. However, it's rare that anything serious could happen.
it may be your fuel pressure regulator leaking. On my 2002 3.4l impala, it is located just below the throttle body. follow the fuel line up, it should be just before the injection manifold. if you seee gas leaking, get it replace soon as it could cause a fire. thre may be a safety recall on it.
I would suspect low fuel pressure would cause both conditions.
I would guess about six quarts...