I have an 02 A4 Quattro 5 Spd Mnl Tran w/ +100,000 miles.

When I turn on my car it makes a "scrapping" noise from under the hood. It doesnt make this noise when it is turned on for the first time in the day. About 8 hours since it was last on. Everytime after that it makes the loud noise. The noise lasts about 1 second and dies out. Any help? Thanks.

 

the only ignition noise i kno of is a spark knock... no scraping... or scrapping...

but it is possible... that you have something affecting your base timing or cam timing... and when started this happens... and the ECU compensates for this... by adjusting timing...

i can't say for sure... cause its not a typical where people refer scrapping to ignition. it would be something i would have to hear and see for myself... and i think almost everyone is gonna say the same thing.

 

I had a similar problem and it turned that my cam crank tensioner was not working properly added needed replaced that was at about 75000 miles. wasn't cheap. Like Knight Fall said without actually hearing the sound i could't say for sure but what you described seemed like what mine was doing. Along with the tensioner i had the mechanic replace my water pump and timing beltas preventative maintanceall said and done wasabout $2200.