Its the color wheel in all probability the bearings go on the motor and cause this dreadful noise
The color wheel will need to be replaced available here
Here is an article that will make you understand this problem better and with a fix
And here is a guy actually doing the job
A technician would charge $300-$400 depending on where you are
Let me know if you need more info
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Should we replace the two fans as well seeing as we will have the back off and parts out to replace the wheel? Then all possibilities of noise makers are taken care of?
The fans wont make the picture not appear if they fail they cause overheating issues
Usually the color wheel makes this dreadful humming or screeching noise the lamp wont fire up (because of it) and you get 3 blinking lights in the front