Q: My tire went flat. Loud screeching noise since putting on spare tire.

It’s apparent due to timing that something to do with the new tire is your source for unwanted sound. Something is making contact to something else that it should not be. You need to start by removing the spare tire that was installed and doing a visual inspection. Look for any debris, or foreign objects that may have gotten into the wheel assembly. Secondly, inspect the brakes and make sure they are in place and mounted correctly. Check the spare tire and make sure it sits properly onto the hub. You also want to assure that the spare tire has its lug nuts properly torqued down within specifications. If you need to have this checked, a qualified professional from YourMechanic can come to your car’s location to diagnose the noise and advise on a repair.