Maxima Forums - Help please! can't work out why car is whistling/whining... :(

I've noticed over the past few days that my car's making a whistling/whining sound. It doesn’t happen when the car is idle, or when i rev the car in neutral, i can only hear it when i accelerate lightly with overdrive on, between 30-40mph. It sounds like it’s coming from the engine bay, and I'm not sure if the extra engine noise is the reason I cannot really hear a whistle/whining sound when the engine is not in overdrive.

It started to happened I think after cleaning my MAF, throttle body IAVC and air filter by pulling it all apart while replacing my KS, although all the hoses/lines seem to be all connected fine upon triple checking. One thing that concerns me though, is the upper intake tube at the point where it joins and feeds directly into the air box, hasn’t got any foam lining around the edges anymore. It got wet and came off while i cleaned it. The intake pipe it's quite loose, when i push it, it moves a few cm at the join on the air box. I'm not sure if this could be causing a whistle/whine from air escaping out of a gap? Or possibly the throttle opening, where it lets air into the upper manifold?

I’m also worried it may be my tranny, the reason being is cos the whistle/whine only happens around 30-40 miles, and doesn’t seem to happen at lower speeds, in lower gears. It increases with pitch though as I speed slowly from 30-40mph though.

Any help would be greatly appreciated thanks.