it could be your valves or your engine
Most common culprit is a slipping belt.
It depends on the nature of the noise.
Most likely it is coolant getting to hot and boiling over, car is most likely overheating. Check for fluid under car, and temperature gauge.
If the whistling noise is coming from under the hood its your belt, that's what's wrong with my Sequoia. If its not coming from under the hood its probably a crack in the seem of your window.
There is a baby under the hood.
What causes ticking, check engine light, and the check gauges sensor to come on in a 1999 Dodge Durango 5.2L SUV?
Something is wrong. Have a trusted mechanic check it out before you get stuck.
Serious engine knock or valve train noise. Have this looked into by a pro.
Sparks under the hood of a car are caused by shorts in the electrical system. A broken wire or loose connection is usually the culprit.
The most common cause behind a high pitched noise under the hood is the drive belt. if it is worn out or loose, the wheels will slip, creating the noise. I would check to make sure the tensioner isn't bad. If it is, this could be causing the looseness. If the tensioner is fine, then just replace the belt.
i don't know if this is the same problem but when i had a screeching noise from under the hood it was from the fan belt. it needed to be replaced. the best thing to do is bring it in to a shop and have them find it.