dancs1.8t

Started timing belt job on a 2002 A6 3.0 after it started misfiring and the coil packs and plugs checked out ok...and saw this on the passenger side exhaust camshaft. It's the third valve from the rear...

What is that under the lobe? It looks like a 9mm socket -- is it a valve keeper or spring retainer???

I've always noticed a bit of valve noise coming from that area, but nothing crazy...just thought it was normal audi valve noise.

Guess i'll be taking the head of to see what the total damage is.

2.7Lturbo

engine rebuild..... sorry bro, and yeah that does look like a socket, who was the last person in there lol

4Driver4

Not the first 3.0 engine to have this happen.

dancs1.8t

the lifter disintegrate?

4Driver4

The cam. The dealer will replace the head to fix the problem. Has claimed inadequate lubrication due to crank vent issues, I hear.

dancs1.8t

but what is under the lobe and why does the lifter look hollow? I can understand the cam wearing due to insufficient lubrication, but I don't understand what I see under it...

4Driver4

It looks like the lifter is worn right through and you are seeing the "guts" of the hydraulic lifter. It is hollow.

SloopJohnB@mac.com

I don't know that you need a head rebuild..it may be nothing more than a new cam and hydraulic followers.

Old school, you had to replace whatever the cam lobes rubbed/rolled on when you replaced a cam because the cam/followers wore/matched to each other. Surely you'll have to replace the camshaft and the one damaged follower/hydraulic lifter, but I don't know what today's mfg tolerances allow. The sure thing is to replace all the hydraulic lifters that the new cam lobes touch.

A worn cam lobe shouldn't affect the head...the valves won't open as far as they should.

I lay these failures on the reduction in zinc thiophosphate in lubricating oils....arguably it reduces the life of catalytic converters and has therefore been reduced in new specs for oils. IIRC, and as noted in wiki, beginning in 2006, a rapid phaseout of ZDDP in engine oils began.

There are oils that are allowable in your engine that are spec'd to prior to 2006 with higher levels of ZDDP you might consider using. For example, I've used amsoil 15W-40 synthetic marine/diesel oil in our 2K4.2 for over 140K miles with no engine wear issues...I've recently switched to amsoil 5W-40 euro-spec formula because of the 02 S6 and I don't want to fool around with 3 separate oil requirements (the M3 is bad enough with a 10W-60 unique requirement). The marine/diesel oil has a good level of EP additive as well as anti–corrosion additive useful for marine engines that may not be started or run for weeks at a time.

http://www.amsoil.com/storefront/afl.aspx 5W-40

http://www.amsoil.com/storefront/afl.aspx 15W-40

2.7Lturbo

i would engine rebuild on the fact that those metal shavings from the camshaft had to go somewhere..... but then again i also have 2 turos to worry about

Just Me

has the oil ever been changed? That's amazing.