Slightly High Pitched Noise When Stopped/idle

[R33Sky'N1aGf101]

Hi everyone, Just curious if anyone has experienced this before or could give me some ideas as to what to look for?

I rarely drive my R33 4 door, Automatic Skyline, but as it sits under a car cover I have been hoping it would stay in the similar condition.

The other day I took my car out for a drive and noticed very quickly that it had developed a hollow high pitched noise when slowly driving and when stopped with the brake fully engaged. The high pitched sound seemed most frequent while idling or moving through the automatic gears, and didn't seem totally go away even when the engine was fully warm. May have lessened, possible after a long drive, but am still worried about it.

Could be something to do with it not having been driven in 2 weeks, I was slow with the first 10km of the drive to allow the oils to circulate, but its still a weird noise. I did look in the engine bay but the noise seemed to be coming from inside the car, either that or it stopped by the time I had got to the engine to check.

Any ideas for areas to check first and i'll give them a look.

[GTR-N1]

When you alter the throttle position from the engine bay, is the squeal coming from a belt?

Any different when you engage air cond?

[sonicz]

Fuel pump? Electrical interference coming from your speakers? I have had both of these in a r33.