The whining is a tell-tale sign of electrical noise in the system. Typically from an alternator/charging system.
If the radio plays fine with the engine not running, the radio itself is not the trouble-maker.
If, when the engine is running, give it a couple good revs
Does the sound seem to correlate with the engine's rpms???
If so you have:
1)Charging problems (as described above)
2)Ground problems (see my earlier post)
A WHINE was stated, not any other noise. If it was spark plug related it would sound like a radio on AM with a hair-dryer close to it, crackling hissing popping noise.
I KNOW, I custom made tach for my '70 and got in a hurry and ran the coil input wire too close to the radio's antenna, now I hear the "sparkplug dance" on weaker AM stations.
Shawn (and to anyone else curious),
The hood ground is there to ensure the metal hood is in good contact with the rest of the body, "simulates" one whole piece of metal (the whole car body). This makes a consistant ground with optimizes radio reception, because the ground is the other element of a radio antenna system.
The radio is then "tuned" to the sheet metal of the car. How is this done?
The "trimmer" is adjusted. The tuning knob is removed and in the small hole is a trimmer capacitor that is turned until a weak station (near 1400 kHz on the AM band) is rec'd with the most output. This signals the antenna is "trimmed" to the vehicle for optimum performance.
You really don't need that hood ground, but reception and innerference may arrise. But the original question stated--a whining noise indicating a engine electrical source innerference problem.
I not going to totally rule out the fiberglass hood, but it really doesn't sound like it to me.
-auto radio repair tech
-creator of Team Chevelle's radio pages