First post- I am a prospective mazda3 buyer and test drove 6 different ones today. I tested used mazda3's from 2005 to 2008 models. On 3 of the 6, the ignition made a strange noise upon turning the key.

Upon turning the key and starting the car, the engine made a grinding noise, sounding like metal scraping on metal. Once the engine got running it went away, or atleast I didnt notice it. Every time I started these three cars it did it.

The first one I heard it on, I figured the car was messed up and wrote it off. I went on to test 2 others that made an identical noise and got worried. Is this normal? Im obviously not going to buy a used car with mechanical issues, but if 3 of the 6 i tried made the same noise, is it normal? If its a problem, any clue what it could be? The cars otherwise ran perfectly fine. Thanks for any input.