Whistling noise

Hey guys. It's been a long time since I have been on here but I am hoping for some help. My 13 tacoma 2wheel dr. 2.8l has a whistle while running and gets quiet as it warms. Any ideas.

 

Leaky engine gasket? When it heats it reseals? My Wrangler did that. Then started to drop oil pressure at idle. Normalized when combustion resumed. Just a guess though.

 

It could be a lot of things... But a leaking vacuum hose or an intake gasket are very likely candidates.
Get a can of carb cleaner and using the tube nozzle spray it around the intake runner where it connects to the head. If you hear or see a change in the engine idle or the whistling stops momentary then that is where the leak is.

 

Is it very loud? And while you're driving? This isn't really advice but maybe piece of mind if it sounds similar to mine. Mine whistles sometimes. It's done it for a while, I think it's just the throttle body. I'll hear it sometimes when I step on the accelerator. It's faint. Usually makes a whistle/wine on a cold start too. Throttle open to run rich for the first few minutes combined with the 2ndary air injection system. The 4 bangers are just kind of rough/loud engines. Cleaning the throttle body might help.