Wow! How does this engine run apart from the lack of noise?
Audi A4 cam wear
- Thread starter dlundblad
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He says he removed the valve cover gasket because it was leaking; obviously there are no other symptoms; if he had not taken this picture or if the valve cover gasket were not leaking, would he have noticed anything wrong in the engine?
Do other Audi owners have problem with the cam before realizing it needs replacing? I mean nobody takes the valve cover off to make sure the camshaft is still intact!
Do other Audi owners have problem with the cam before realizing it needs replacing? I mean nobody takes the valve cover off to make sure the camshaft is still intact!
If you used MMO that wouldn't have happened. But seriously, wow, that is chewed up. Im really surprised there weren't more symptoms that you would have noticed right off the bat. Must be a manufacturers defect in materials. Sorry to see that...
Originally Posted By: jk_636
If you used MMO that wouldn't have happened. But seriously, wow, that is chewed up. Im really surprised there weren't more symptoms that you would have noticed right off the bat. Must be a manufacturers defect in materials. Sorry to see that...
LOL! as if mmo can fix a casting/metallurgy issue on defective camshaft.
If you used MMO that wouldn't have happened. But seriously, wow, that is chewed up. Im really surprised there weren't more symptoms that you would have noticed right off the bat. Must be a manufacturers defect in materials. Sorry to see that...
LOL! as if mmo can fix a casting/metallurgy issue on defective camshaft.
Originally Posted By: Quest
Originally Posted By: jk_636
If you used MMO that wouldn't have happened. But seriously, wow, that is chewed up. Im really surprised there weren't more symptoms that you would have noticed right off the bat. Must be a manufacturers defect in materials. Sorry to see that...
LOL! as if mmo can fix a casting/metallurgy issue on defective camshaft.
Yep how can you fix something that was already broken to begin with. A defective camshaft is a defective camshaft nothing is going to prevent it from looking that way.
Originally Posted By: jk_636
If you used MMO that wouldn't have happened. But seriously, wow, that is chewed up. Im really surprised there weren't more symptoms that you would have noticed right off the bat. Must be a manufacturers defect in materials. Sorry to see that...
LOL! as if mmo can fix a casting/metallurgy issue on defective camshaft.
Yep how can you fix something that was already broken to begin with. A defective camshaft is a defective camshaft nothing is going to prevent it from looking that way.
Originally Posted By: Vikas
Do other Audi owners have problem with the cam before realizing it needs replacing? I mean nobody takes the valve cover off to make sure the camshaft is still intact!
Audi has yet to build a vehicle where the valve cover didn't need to come off regularly, like every 40-50k miles, to seal leaks. The 30V V6 is the pinnacle of oil leakage.
Typically, there will be a misfire code because at some point the cam lobe will be so worn down the valve will hardly open anymore.
Do other Audi owners have problem with the cam before realizing it needs replacing? I mean nobody takes the valve cover off to make sure the camshaft is still intact!
Audi has yet to build a vehicle where the valve cover didn't need to come off regularly, like every 40-50k miles, to seal leaks. The 30V V6 is the pinnacle of oil leakage.
Typically, there will be a misfire code because at some point the cam lobe will be so worn down the valve will hardly open anymore.
Any updates on this? Did your dad get it fixed? What did it end up costing him?
Wow that’s a severely damaged cam, plus I guess I am pretty late to this party, LOL.
I would love to see some more angles and the mating parts to put then against my Rockwell testers to be really conclusive but it appears that more likely than not that the cam in question was not defective in and of itself but rather has been damaged as the result of some type of mechanical event within the valve it is driving gradually over thousands of cycles.
It’s clear that this cam is a standard induction treated (as opposed to furnace hardened) and ground cam and no nitriding or anything else. That pretty much eliminates the possibility of the elusive “soft lobe” defect that everybody believes in but never actually produces.
It’s also only surface hardened not through hardened (as evidenced by the chipping at the lobe- no hardened metal would fracture like that) Granted that’s pretty standard for low impact cams but when they few mils wears away for any reason the end result is exactly what you see here- a grey fine grained surface.
My “guess” is that the lubrication had no part to play in this failure as evidenced by the wear finish and the overall condition of everything else.
Hardly a diagnosis I would bet on just from a 1 plane view of one part of a failure event but cam failures as a rule follow the same patterns because cams ( with the possible exception of the Geneva cam) all function and rotate basically the same. I would suggest completely evaluating the valve train when doing this repair.
I would love to see some more angles and the mating parts to put then against my Rockwell testers to be really conclusive but it appears that more likely than not that the cam in question was not defective in and of itself but rather has been damaged as the result of some type of mechanical event within the valve it is driving gradually over thousands of cycles.
It’s clear that this cam is a standard induction treated (as opposed to furnace hardened) and ground cam and no nitriding or anything else. That pretty much eliminates the possibility of the elusive “soft lobe” defect that everybody believes in but never actually produces.
It’s also only surface hardened not through hardened (as evidenced by the chipping at the lobe- no hardened metal would fracture like that) Granted that’s pretty standard for low impact cams but when they few mils wears away for any reason the end result is exactly what you see here- a grey fine grained surface.
My “guess” is that the lubrication had no part to play in this failure as evidenced by the wear finish and the overall condition of everything else.
Hardly a diagnosis I would bet on just from a 1 plane view of one part of a failure event but cam failures as a rule follow the same patterns because cams ( with the possible exception of the Geneva cam) all function and rotate basically the same. I would suggest completely evaluating the valve train when doing this repair.
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