my car makes a sound similar to a chainsaw starting up when I turn the ignition

What is your question?

The car starts and drives fine but it makes this chainsaw noise when starting. If the car is cold, the sound is quite loud. However, if I drive and then only leave it for say 20 minutes, the sounds is much quieter. I thought it was an oil problem, so I added a bit of extra oil. It fixed the problem temporarily, but soon the sound was back again. Is this a problem with the oil level? Could there be a hole somewhere? A few months ago there was a leak and I used K-seal in the oil tank. It seemed to fix the problem. I also aded distilled water to the tank to try and remedy the problem. Been running fine till now. Also, I use suction to change my oil instead of draining. Is it possible that there is old oil still in the tank that is causing this problem? My car is almost 9 years old, Mercedes C63. I love it so much and despite having taken great care of it the problems have been accumulating lately. I'm afraid that if I don't fix this problem soon, I won't be able to drive it anymore.

What makes this problem better or worse?

worse when engine is cold

How long has your 2009 Mercedes-Benz C63 AMG had this problem?

a month or so?