To late to edit - it must be motorcycles. I haven't done many car engines in the last 10 years, we just replace them now, but have still been inside a few motorcycle engines. They don't use rails and expanders, they use slotted cast iron oil rings...with a coil expander.
Audi Broken Oil Control Rings - Why???
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Originally Posted By: SonofJoe
Originally Posted By: edwardh1
again, what changed from the year before?
I think the Audi 2.0L TFSI was a wholly new engine introduced in 2008 and reports of high oil consumption emerged quite quicky. I think I'm right in saying that this was the first high performance production engine to feature both a turbo and direct gasoline injection so it was pioneering stuff.
Yes a new design and it won the 2009 & 2010 International Engine of the Year award.
Originally Posted By: edwardh1
again, what changed from the year before?
I think the Audi 2.0L TFSI was a wholly new engine introduced in 2008 and reports of high oil consumption emerged quite quicky. I think I'm right in saying that this was the first high performance production engine to feature both a turbo and direct gasoline injection so it was pioneering stuff.
Yes a new design and it won the 2009 & 2010 International Engine of the Year award.
Originally Posted By: SR5
Originally Posted By: SonofJoe
Originally Posted By: edwardh1
again, what changed from the year before?
I think the Audi 2.0L TFSI was a wholly new engine introduced in 2008 and reports of high oil consumption emerged quite quicky. I think I'm right in saying that this was the first high performance production engine to feature both a turbo and direct gasoline injection so it was pioneering stuff.
Yes a new design and it won the 2009 & 2010 International Engine of the Year award.
Oh the irony!!
Originally Posted By: SonofJoe
Originally Posted By: edwardh1
again, what changed from the year before?
I think the Audi 2.0L TFSI was a wholly new engine introduced in 2008 and reports of high oil consumption emerged quite quicky. I think I'm right in saying that this was the first high performance production engine to feature both a turbo and direct gasoline injection so it was pioneering stuff.
Yes a new design and it won the 2009 & 2010 International Engine of the Year award.
Oh the irony!!
Yeah, engine of the year results are a joke - they should be tested when 10 years old, not when new.
Originally Posted By: Silk
I think this is the reason, steel rail oil ring is quite stiff. Over 30 years ago I did a ring job on a 161 Holden engine, should of had it rebored, but the solo mum was stapped for cash. The bore looked like those corugated baked beans tins, and I used 4 piece oil rings in it...and it turned into a nice runner. A few years later and another owner, and it came back to me with a blown headgasket, and the bores were nice and smooth. So pretty agressive.
I've seen those cast iron oil rings with coil spring expander before, but can't remember which engine - too many engines, and too many years.
First look at this thread, and my first thought was too much "vertical" clearance, making these things bend (and snap) for some reason.
I got given a melted Toyota D4D 3L piston a couple years ago (it's on my desk), and it had exactly this style of oil control ring, pretty fragile being bent out of plane (i.e. OK for installation stretch, but not acrossways.
My second Torana was a 161...was playing WRC in the pine forests, and over-revved it massively only a couple of times before it stopped playing.
I think this is the reason, steel rail oil ring is quite stiff. Over 30 years ago I did a ring job on a 161 Holden engine, should of had it rebored, but the solo mum was stapped for cash. The bore looked like those corugated baked beans tins, and I used 4 piece oil rings in it...and it turned into a nice runner. A few years later and another owner, and it came back to me with a blown headgasket, and the bores were nice and smooth. So pretty agressive.
I've seen those cast iron oil rings with coil spring expander before, but can't remember which engine - too many engines, and too many years.
First look at this thread, and my first thought was too much "vertical" clearance, making these things bend (and snap) for some reason.
I got given a melted Toyota D4D 3L piston a couple years ago (it's on my desk), and it had exactly this style of oil control ring, pretty fragile being bent out of plane (i.e. OK for installation stretch, but not acrossways.
My second Torana was a 161...was playing WRC in the pine forests, and over-revved it massively only a couple of times before it stopped playing.
Originally Posted By: crazyoildude
JHogan How is Audi about covering this under warranty? Just curious.
Originally Posted By: JHogan
Originally Posted By: SonofJoe
Originally Posted By: JHogan
I'm a writer with Middleburg Heights Audi in Ohio. And its still a very prevalent problem. Just next week alone we have scheduled 4 2.0 TFSI engines for piston replacement covered under Audi. Out technician alone has done over 800 of these by himself.
Hi. I know Audi have stepped up to the plate and paid to get these problematic engines fixed. However they have been extremely tight lipped as to what the original cause of the problem was. The 'bad batch of piston rings' excuse does not 'ring' true to me. They're piston rings for Heaven's sake! Unless you made them out of plasticine, what could go wrong with them?
I think what's always concerned me is not Audi's problems per se (after all this is now in the past), it's what lessons this might hold for the future of engine oils in general; particularly high Noack oils which will in theory still be allowed in GF-6 and oil-induced knock/detonation effects.
Yes even the technicians aren't exactly sure what the true issues are. They do two different stages of testing to determine if the engine needs pistons. All they do is submit said data to Audi and they make that determination, which I've yet to see one not get approved. They've even approved some that weren't part of the warranty extension...All I know is every one of these engines I see that have this issue have one thing in common. That is that there is an irregular amount of sludge and carbon build up, both in the top of the head and the pistons themselves.
JHogan How is Audi about covering this under warranty? Just curious.
Originally Posted By: JHogan
Originally Posted By: SonofJoe
Originally Posted By: JHogan
I'm a writer with Middleburg Heights Audi in Ohio. And its still a very prevalent problem. Just next week alone we have scheduled 4 2.0 TFSI engines for piston replacement covered under Audi. Out technician alone has done over 800 of these by himself.
Hi. I know Audi have stepped up to the plate and paid to get these problematic engines fixed. However they have been extremely tight lipped as to what the original cause of the problem was. The 'bad batch of piston rings' excuse does not 'ring' true to me. They're piston rings for Heaven's sake! Unless you made them out of plasticine, what could go wrong with them?
I think what's always concerned me is not Audi's problems per se (after all this is now in the past), it's what lessons this might hold for the future of engine oils in general; particularly high Noack oils which will in theory still be allowed in GF-6 and oil-induced knock/detonation effects.
Yes even the technicians aren't exactly sure what the true issues are. They do two different stages of testing to determine if the engine needs pistons. All they do is submit said data to Audi and they make that determination, which I've yet to see one not get approved. They've even approved some that weren't part of the warranty extension...All I know is every one of these engines I see that have this issue have one thing in common. That is that there is an irregular amount of sludge and carbon build up, both in the top of the head and the pistons themselves.
I keep going back to this video and noticing new things.
Early on, the guy points to pistons 2 & 3 and says these rings have broken in the same spot. He then picks up piston 4 and says the ring is still in place and points to the same spot (I'm going to hazard a guess and say this is the thrust side of the piston). Now look at the piston 4 piston skirt. Is it me or does that look both badly worn and scuffed? Could this be significant as this seems to be where the rings are breaking?
Secondly, I can't quite get a proper view but is part of the bottom of the third groove 'missing' to accommodate the gudgeon pin? This being the case, shouldn't there be thin support rail underneath the oil ring to stop the ring being stressed over the two gaps?
Third, one of the things that's striking about this video is how the pistons and rods are so appallingly filthy while at the same time, the sump is so clean. The synthetic oil used in this car has done a good job of keeping a lot of stuff in solution but like most oils, it was never designed to deal with properly burnt oil. We have come to believe that synthetic oils are so much better than mineral oils but if you set fire to them, they are remarkably similar!!
Early on, the guy points to pistons 2 & 3 and says these rings have broken in the same spot. He then picks up piston 4 and says the ring is still in place and points to the same spot (I'm going to hazard a guess and say this is the thrust side of the piston). Now look at the piston 4 piston skirt. Is it me or does that look both badly worn and scuffed? Could this be significant as this seems to be where the rings are breaking?
Secondly, I can't quite get a proper view but is part of the bottom of the third groove 'missing' to accommodate the gudgeon pin? This being the case, shouldn't there be thin support rail underneath the oil ring to stop the ring being stressed over the two gaps?
Third, one of the things that's striking about this video is how the pistons and rods are so appallingly filthy while at the same time, the sump is so clean. The synthetic oil used in this car has done a good job of keeping a lot of stuff in solution but like most oils, it was never designed to deal with properly burnt oil. We have come to believe that synthetic oils are so much better than mineral oils but if you set fire to them, they are remarkably similar!!
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well, you'd be the one to ask, I suppose... how clean do PAO or alkylated naphtalenes or esters burn compared to mineral base stocks?
I would think the stuff left over from burning is the additive package (VII mostly?)
I would think the stuff left over from burning is the additive package (VII mostly?)
Originally Posted By: Jetronic
well, you'd be the one to ask, I suppose... how clean do PAO or alkylated naphtalenes or esters burn compared to mineral base stocks?
I would think the stuff left over from burning is the additive package (VII mostly?)
This question has been asked before. Mineral oils are far less oxidatively stable than synthetics so in theory should burn (which is just a very extreme form of oxidation!) far easier. I seem to recall that Mazda's rotary engines specify mineral oils which may be suggest this to indeed be the case.
I suspect that the bulk of the crud you can see on the pistons and rods is partially burnt oil rather than additive. First, there are a lot of additive molecules which are significantly lighter and chemically more reactive than base oil so would burn first rather than last. Second, if you subscribe to the theory that oil exits the crankcase driven by vapour-liquid equilibrium (I do!) then what goes through the PCV will be light base oil (and the most volatile additives) and what's left in the crankcase is the heavier base oil and all the heavy additives (like ashless dispersants and VII polymers). If this is true, the heavier additives would never make it through to the cylinder to be burnt.
Okay, this is all speculation on my part but it sort of sounds right.
well, you'd be the one to ask, I suppose... how clean do PAO or alkylated naphtalenes or esters burn compared to mineral base stocks?
I would think the stuff left over from burning is the additive package (VII mostly?)
This question has been asked before. Mineral oils are far less oxidatively stable than synthetics so in theory should burn (which is just a very extreme form of oxidation!) far easier. I seem to recall that Mazda's rotary engines specify mineral oils which may be suggest this to indeed be the case.
I suspect that the bulk of the crud you can see on the pistons and rods is partially burnt oil rather than additive. First, there are a lot of additive molecules which are significantly lighter and chemically more reactive than base oil so would burn first rather than last. Second, if you subscribe to the theory that oil exits the crankcase driven by vapour-liquid equilibrium (I do!) then what goes through the PCV will be light base oil (and the most volatile additives) and what's left in the crankcase is the heavier base oil and all the heavy additives (like ashless dispersants and VII polymers). If this is true, the heavier additives would never make it through to the cylinder to be burnt.
Okay, this is all speculation on my part but it sort of sounds right.
https://www.youtube.com/watch?v=AQAHpwkGuUE rings & piston video from Dart.
This isn't the first time the company had a ring problem.
The VW 2.Slow in the MKIV Jetta would often develop oil consumption due to piston rings.
The VW 2.Slow in the MKIV Jetta would often develop oil consumption due to piston rings.
Originally Posted By: crazyoildude
JHogan How is Audi about covering this under warranty? Just curious.
Audi is actually pretty good with covering this. Even with not much maintenance records they're pretty decent about taking care of it. Since I've worked here they have yet to decline replacement of one covered under the specific extension.
JHogan How is Audi about covering this under warranty? Just curious.
Audi is actually pretty good with covering this. Even with not much maintenance records they're pretty decent about taking care of it. Since I've worked here they have yet to decline replacement of one covered under the specific extension.
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Originally Posted By: artificialist
The VW 2.Slow in the MKIV Jetta would often develop oil consumption due to piston rings.
That's because they were mistakenly installed upside down at the factory on a large number of these engines.
The VW 2.Slow in the MKIV Jetta would often develop oil consumption due to piston rings.
That's because they were mistakenly installed upside down at the factory on a large number of these engines.
Originally Posted By: JHogan
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Thanks JHogan for this brand new info. I'd heard that Audi were fitting new pistons to affected engines in the UK but I'd assumed these were re-designed slightly longer to accommodate thicker rings. That the original pistons were too narrow never occurred to me but yes, this would go a long way to explaining why these engines burnt a more than usual amount of oil from the day they left the showroom. It also explains some of the early reports I picked up on from the US, where new piston rings were fitted to affected engines but did nothing to fix the excessive oil consumption. Given that an undersized piston would be more prone to 'slap', it also goes some way to explaining the scuff marks on Piston 4 in the video.
Understanding the technicalities of this engine problem is tricky. Understanding how some of the best automotive engineers in the world could get something like this so wrong is far more difficult to understand!
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Thanks JHogan for this brand new info. I'd heard that Audi were fitting new pistons to affected engines in the UK but I'd assumed these were re-designed slightly longer to accommodate thicker rings. That the original pistons were too narrow never occurred to me but yes, this would go a long way to explaining why these engines burnt a more than usual amount of oil from the day they left the showroom. It also explains some of the early reports I picked up on from the US, where new piston rings were fitted to affected engines but did nothing to fix the excessive oil consumption. Given that an undersized piston would be more prone to 'slap', it also goes some way to explaining the scuff marks on Piston 4 in the video.
Understanding the technicalities of this engine problem is tricky. Understanding how some of the best automotive engineers in the world could get something like this so wrong is far more difficult to understand!
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Originally Posted By: SonofJoe
Originally Posted By: JHogan
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Thanks JHogan for this brand new info. I'd heard that Audi were fitting new pistons to affected engines in the UK but I'd assumed these were re-designed slightly longer to accommodate thicker rings. That the original pistons were too narrow never occurred to me but yes, this would go a long way to explaining why these engines burnt a more than usual amount of oil from the day they left the showroom. It also explains some of the early reports I picked up on from the US, where new piston rings were fitted to affected engines but did nothing to fix the excessive oil consumption. Given that an undersized piston would be more prone to 'slap', it also goes some way to explaining the scuff marks on Piston 4 in the video.
Understanding the technicalities of this engine problem is tricky. Understanding how some of the best automotive engineers in the world could get something like this so wrong is far more difficult to understand!
I've often wondered the same thing, more importantly at least they are correcting the mistake and there is not an issue like that with the newer models. Well so they say.
Originally Posted By: JHogan
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Thanks JHogan for this brand new info. I'd heard that Audi were fitting new pistons to affected engines in the UK but I'd assumed these were re-designed slightly longer to accommodate thicker rings. That the original pistons were too narrow never occurred to me but yes, this would go a long way to explaining why these engines burnt a more than usual amount of oil from the day they left the showroom. It also explains some of the early reports I picked up on from the US, where new piston rings were fitted to affected engines but did nothing to fix the excessive oil consumption. Given that an undersized piston would be more prone to 'slap', it also goes some way to explaining the scuff marks on Piston 4 in the video.
Understanding the technicalities of this engine problem is tricky. Understanding how some of the best automotive engineers in the world could get something like this so wrong is far more difficult to understand!
I've often wondered the same thing, more importantly at least they are correcting the mistake and there is not an issue like that with the newer models. Well so they say.
Originally Posted By: SonofJoe
Originally Posted By: JHogan
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Thanks JHogan for this brand new info. I'd heard that Audi were fitting new pistons to affected engines in the UK but I'd assumed these were re-designed slightly longer to accommodate thicker rings. That the original pistons were too narrow never occurred to me but yes, this would go a long way to explaining why these engines burnt a more than usual amount of oil from the day they left the showroom. It also explains some of the early reports I picked up on from the US, where new piston rings were fitted to affected engines but did nothing to fix the excessive oil consumption. Given that an undersized piston would be more prone to 'slap', it also goes some way to explaining the scuff marks on Piston 4 in the video.
Understanding the technicalities of this engine problem is tricky. Understanding how some of the best automotive engineers in the world could get something like this so wrong is far more difficult to understand!
Sometimes over-engineering can get you in trouble
Originally Posted By: JHogan
Also I've learned Audi's reasoning behind these issues. According to what the technician that performs these repairs, he says Audi Tech line has told him the reasoning is because the pistons from the factory are too small in diameter for the cylinder. The remedy has been to take new pistons designed for the last gen A3 and install those. Apparently these are the correct size.
Thanks JHogan for this brand new info. I'd heard that Audi were fitting new pistons to affected engines in the UK but I'd assumed these were re-designed slightly longer to accommodate thicker rings. That the original pistons were too narrow never occurred to me but yes, this would go a long way to explaining why these engines burnt a more than usual amount of oil from the day they left the showroom. It also explains some of the early reports I picked up on from the US, where new piston rings were fitted to affected engines but did nothing to fix the excessive oil consumption. Given that an undersized piston would be more prone to 'slap', it also goes some way to explaining the scuff marks on Piston 4 in the video.
Understanding the technicalities of this engine problem is tricky. Understanding how some of the best automotive engineers in the world could get something like this so wrong is far more difficult to understand!
Sometimes over-engineering can get you in trouble
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