eknight63

I posted this over on the 2.7T forum but there is more traffic on this one, any suggestions would be appreciated!

I recently installed two APR diverter valves and the APR bi-pipe on a `02 A6. Since then on a cold starts in the morning I hear a very loud and noticeable noise coming from the engine bay on what seems to be the right hand side (if sitting in driver seat) the closest thing I can describe it to would be a rip or circular saw type noise as it cuts through a piece of wood. I only hear the noise while the EGR valve is engaged, as soon as it lets go the noise goes away, you can actually hear (I think turbos) wind down. It does not seem to have any affect on the car while driving or starting up but it is bothersome and I don't want to let it lead to future problems. I spoke with a service manager at a trusted dealership ans he siggested that the secondary air pump was having issues, based on the noise I described. But after doing a little research I found it could alos be the Combi-valve, and or clogged EGR valve. Also it does not make a difference if the AC is on or off.
Any thoughts or things I should check would be helpful?

Thanks

Boston Driver

...if you have access to one (perhpas someone local to you can help), run a scan to see if anything comes up.

eknight63

Thanks, I will try and track one down in my area. If you can think of any other ideas let me know.

Thanks!