I replaced the ignitor in my hotpoint oven. Now I turned the gas back on and there is a high pitch noise and a gas smell.

SOURCE: frigidaire oven

Your oven valve won't open all the way

SOURCE: Hotpoint gas oven

Most common problem is the ignitor.

SOURCE: Amana oven gas leak issue

staunch has no idea what he is talking about. It has nothing to do with the igniter, or it would fire up at all. Since you are saying that your oven does ignite and heat up, it is the internal gas valve that is the problem.

The way all recent (20 year at least) are designed, the gas valve internally can not open unless the igniter is working, for obvious reasons ... boom! The igniter circuit allows the gas valve to open, once it detects that the igniter is ready to "ignite" a gas flow. BUT, the valve can be bad in the AMOUNT of gas being delivered. Your's is allowing too much gas, more than can be burned, hence the smell.

DON'T use the oven until you have a qualitifed tech come out and replace the valve. It is very dangerous for you to do it yourself.

SOURCE: high-pitched squeal/whistle noise from range

Noise went away by itself. No root cause found. Please remove this posting, thanks.

SOURCE: constant high pitched noise emitting from furnace

Hi,
This is probably a dry bearing in the vent motor. Those motors run at high RPM's and can make a deafening high pitched squeal if they become dry and need oiling.
Some of the motors have oil cups on them for dripping oil into and others;s are much more difficult as you need to guess where the bearing is and try to drip oil down into them or run the oil to them.
Any light weight small motor oil ike a sewr machine oil will work.
Many hardwares have small oil bottles with extending spouts made just for oiling motors for just a couple of bucks...

The other thing that can cause this is if the blower wheel is coming loose and has moved to the side and is hitting the side of the blower housing. Take the bottom cover off and check for play or movement side to side in the blower wheel. Spinning it with the power off by hand may give you a clue as you will hear it scraping the side of the housing.

Heatman101