WTF??? camshaft lobe practically worn off
AudiWorld Super User
Joined: Jan 2008
Posts: 2,697
Likes: 8
From: NE Ohio
Good Point, any takes on Shell Rotella T6
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
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
Audiworld Junior Member
Joined: Feb 2010
Posts: 56
Likes: 0
From: 18337. Pa.
Same problem here with mine..#2cylinder, rear exhaust lifter/valve. Seems to be the common lobe/lifter issue. I honestly feel being there are so many with the same #2 cylinder, rear exhaust lobe/lifter issue. Well it is a flaw in design by Audi.
I could see if it was a few 3.0 motors here and there. or in differant cylinders. But for what ever reason cylinder #2 rear exhaust lobe/lifter seems to be the ONE to go.
Mine has been in the garage parked, waiting for repair. Atleast shes indoors. Unfortunatly got alot of irons in the fire right now.
I could see if it was a few 3.0 motors here and there. or in differant cylinders. But for what ever reason cylinder #2 rear exhaust lobe/lifter seems to be the ONE to go.
Mine has been in the garage parked, waiting for repair. Atleast shes indoors. Unfortunatly got alot of irons in the fire right now.
Tech Guru
Joined: Oct 2002
Posts: 8,009
Likes: 191
From: Olney, MD
I don't know about Shell Rotella.
I do know what amsoil testing shows WRT synthetic/petroleum oil wear effects.
http://www.amsoil.com/lit/g1971.pdf shows a summary of such independent testing; although rotella is not on the list.
This brochure does have rotella but doesn't address wear. The high initial viscosity shows, however.
http://www.amsoil.com/lit/g2752.pdf
Fair disclosure; I'm a lifetime amsoil dealer but I don't have a downline.
I do know what amsoil testing shows WRT synthetic/petroleum oil wear effects.
http://www.amsoil.com/lit/g1971.pdf shows a summary of such independent testing; although rotella is not on the list.
This brochure does have rotella but doesn't address wear. The high initial viscosity shows, however.
http://www.amsoil.com/lit/g2752.pdf
Fair disclosure; I'm a lifetime amsoil dealer but I don't have a downline.
Tech Guru
Joined: Oct 2002
Posts: 8,009
Likes: 191
From: Olney, MD
Those shavings are probably in the oil sump or the oil filter. Highly unlikely they went anywear (pun intended) in the pressurized oil system unless the oil filter bypass valve was activated AND the meal particulates picked up by the oil pump. Chances are you're ok on that front.
AudiWorld Member
Joined: May 2008
Posts: 112
Likes: 0
Those shavings are probably in the oil sump or the oil filter. Highly unlikely they went anywear (pun intended) in the pressurized oil system unless the oil filter bypass valve was activated AND the meal particulates picked up by the oil pump. Chances are you're ok on that front.
Thread Starter
AudiWorld Member
Joined: Apr 2001
Posts: 140
Likes: 0
That one malfunctioning valve wouldn't explain multiple cylinder misfires, correct? My thought was that the timing belt slipped -- current belt has 60k mi. on it and has a fair amount of cracking on the outside
I already moved coil packs around and replaced plugs to rule those out.
I already moved coil packs around and replaced plugs to rule those out.
AudiWorld Stories
Bringing Audi to Life for Audi Fans
Top 10 Most Expensive Audis Ever Sold on Bring-A-Trailer
Brett Foote
10 Audi Features & Options We Miss the Most!
Joe Kucinski
Audi Recreates Crazy-Looking Speed Record Breaker From 1935
Verdad Gallardo
Coachbuilder Recreates the 1995 Audi TTS Concept
Verdad Gallardo
Every Audi V10 Car Ranked!
Joe Kucinski
9 Audi Designs That Aged Like Fine Wine
Verdad Gallardo
2026 Audi Q5 Buyer's Guide (Every Model Explained)
Brett Foote
Ranking Every Current Audi 'S' Model From Worst to First!
Joe Kucinski
10 Best Audis That are FINALLY LEGAL to Import to the U.S.!
Joe Kucinski
AudiWorld Member
Joined: Mar 2001
Posts: 166
Likes: 1
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.