I just bought a 2000 A6 4.2 with a little noise in valve train. The price was right and I bought accordingly. The Dealership told me it was the Cam chain tensioners making the noise. $3000+ do replace both. Another Audi mechanic told me the only chain in this motor was the oil pump chain? Does anyone know who is correct? does the 2000 A6 4.2 have dual cam chains or what? The noise is only when hot and only on decleration. Very slight @ most. Thx

 

I purchased a 2000 A6 2.8 a couple of months ago so I am new to the Audi brand. I have always been a bit of a do it yourselfer so I decided to purchase the Bentley Publishers repair manual on cd so I could at least make educated decisions on what I can do and what I will leave to the professionals.
According to the manual the 4.2L has a timing belt with a single tensioner pulley.
First -I would be very leery of anybody that told me there was a chain instead of a belt.
Second -I can’t imagine that a mechanic would even think about going on that far without replacing everything that might have a chance to fail. Including the timing belt, tensioners etc...
Third - I don’t know where you live but $3000 seems way to high to me but maybe some of the other guys out there can shed some light on that one.

That’s just my two cents worth
Hope that helps.

 

This mite help, its the back of a 4.2 out of a B6 S4, my understanding is that its similar to your 4.2 but has tha chains etc located at the back of the motor



Good luck trying to count how may chains are there

 

That s4 motor is a little different than the 2000 4.2. The belt drivin 4.2 has chains that drive the camshaft that isnt drivin by the belt. So the first mechanic is correct.