maskinut

I have an 04 s4 4.2 with 48k. When I start the car after it has been sitting overnight there is a tapping that seems to come from the lower center of the engine behind the radio or below. It seems to tap for just under 2 seconds. It goes away and only comes back after the car has been sitting for a while.

Someone told me it was the timing chain tensioner picking up the slack after it has been sitting but I'm not sure...

any ideas?

MYD-WGN

Mine started that when I took it to another dealer for service.I believe its a mix of outside temp and the semisynthetic oil compared to the full synthetic oil my main dealer uses.

DasTrufel

Mainly I have found it to be the tensioner loosing oil when it sits and takes a few seconds to build up oil pressure, alot like a worn lifter.

A8CT

There is a TSB that which describes that as normal. Doesn't sound good but they all do it

jwj

Are these engines using hydraulic lifters or solid lifters. Is it cold outside when this happens?
My guess would be after car sits for awhile and it's cold outside the lifters "tap" for a few seconds until the oil pressure builds. This is normal.