A Year ago I started hearing a vibration/loud buzz kind noise when starting the engine. It was a loud buzz or clicking noise that lasted for a second or two, then stopped. I thought it was exhaust pipe or something. After poking around listening under thecar and under the hood, I located the sound at rear of the engine head. If you put your hand on the camshaft solenoid you can feel it when you hear the sound on startup. This is not like valve noise.

Also I have recently started to hear a similar loud buzz sound at 2000 rpm that sounds like the noise heard at startup. This noise can be heard when cruising slowly in 2 or 3 gear with the passenger window open. The noise occurs around 2k rpm when rpm are rising or falling. Odd noise... could this be another camshaft noise?

What the heck does the solenoid do? Can the solenoid be replaced?

 

Sorry, I forgot to describe the car!
2001 A4 1.8t Quattro, sport suspension, borla exhaust, 92,000 miles.

 

It sounds like I have the same problem, did you ever find a fix for this noise ?

 

I had the same problem, when i took it to the dealer, they replaced the following:
timming belt, water pump and the selinoid. that was when my car had about 65k miles.... now the cars has about 110 and it's starting to do the same. i dont know if its one of these things.
keep us updated!

my car is 2000 A4 1.8T quattro.

 

I had the camshaft tensioner and the chain replaced, since my car had 95k on it when it was fixed. also replaced the timing belt since it has to be removed anyway. The noises all went away, so far. The parts cost $600 (tensioner, chain, gaskets, belt) and the labor was $600.

I heard the noises for 50 k miles, before replacement. It seems to be a realtively minor problem and you can fix it at your convenience. However if you drive hard, it could become a serious problem...