Hi Guys,
I have a 2003 A6 4.2. It was running fine when I had to park it for about 4 months as I had to go away. Now when I start it I get a knocking sound from the Engine..not loud but good enough to be able to hear it when you are near the car. It goes some thing like..taka-taka-taka.. Any idea what could be wrong?

Thanks much.

 

You may be able to close in on where the sound is coming from if you leave the car at idle and listen to different areas with a pipe of some sort. I have a 1 1/2" X 2' steel pipe that I use to listen for the source of noises. From there it may be easier to figure out what the issue is.

Often I've found that noises I think are knocks are really just check valves or other mechanisms that you don't notice unless you listen.

Best of Luck,

--
Paul

 

Probably a lifter hanging up -- Change the oil and put something like 5-20 in for about 500 miles. Let it get warm but don't drive it hard! Then change the oil and use your normal stuff. Do a filter each time....