Hey guys I am a regular forum goer for my other vehicles but am new here. I come to you with a question about my brothers 3.0 a6 2002 with 65K miles on the clock. He bought it earlier this year after he totaled his car in an icy road accident. engine has been running fine up until the last 300 or so miles. I am a very big DIYer and had replaced just about everything on my bimmer and rebuild my cb750K from not working at all so he came to me and asked if I could look at his car because it had developed a ticking in the engine. So I checked it out and looked at the oil. He was about half a quart low so we got some good oil and topped it off. I wrote it off as a noise lifter as my bimmer's are terrible on warm days. To keep it short I changed his oil after this tick started to get louder using mobil 0w40. It hasn't gotten any better so I started digging around to see what I could find and I am seeing horror stories of cam lobes being eaten up and a very long $1,500 job. I am going to pull the valve cover this weekend to check it out. To give more detail it is coming from the passenger side of engine about in the middle of that head. are there any other possibilities? He also said that it is much quieter when her first starts it in the morning and gets louder after things heat up.

 

Have you check the purge valve that's under the airbox? Once the purge valve starts going bad the clicking, ticking or marbels banging sound starts. It could be as simple as a $20 part replacement. But signs of the purge valve going bad could be notice when refueling. The car won't start at first couple of tries, but after that your good.

You should try Total oil Total Quartz INEO MC3 5W30 Engine Oil (1 Quart) - EuropaParts.com with this oil you could let when you need an oil change. Due to the lifter starting tap.
But don't get me wrong, mobil oil, castro oil are great products. But total oil does help those who don't really pay attention to your mileage and oil change schedule(you hear the tapping time to change the oil).

 

Okay how could I check for a bad purge valve

 

Drove the car today. It is by far the laudest at low rpm and right before it shifts at just above 2k rpm. There is no loss of power and still no engine lights.

 

Is the MIL on? If so get a VAG-COM and scan the codes. If not get a VAG-COM and scan it anyway. Pay particular attention to the valve timing and compare the left and right banks. These engines are known to have problem with the chain tensioners used to couple the intake and exhaust cams on each head. As they start to fail you can get these kinds of noises. If you you pull the valve cover look at the tensioners (a brown plastic piece I believe). Make sure that they are not broken. If you find one or both is broken, replace them ASAP. Once they fail you can bend the valves.