Cylinder Scope 2004 C2
#16
Former Vendor
Fuel trim won’t show injectors that leak down when an engine is hot. There’s no data that can be collected via OBDII that will.
It takes old fashioned, hands dirty diagnosis and a human brain to do this.
As far as the collateral damage not effecting “rebuild” from collateral damage... Well, that’s ONLY for our program where the original cylinders are removed with a huge CNC milling machine. The parent material above the cooling jacket is removed entirely, so the more that’s worn away, the less has to be machines. With my program all the things that see collateral damage from this mode of failure are thrown away, no matter if they are good, or bad. Again... These parts are thrown away even if they are in “perfect condition” at the time of disassembly. Why? We know they won’t last as long as the rest of the components that we are replacing, so reusing them is a compromise to save a few dolllars. You won’t find that here, anything that we have identified as a weakness in the platform at the time we complete an engine is replaced, and our base pricing for this includes 100% of these items in 100% of the cases.
Now, to someone who just replaces whats worn, and thats it (pretty much everyone else) the engine wold see extensive collateral damage if it suffered a cylinder scoring event, and resultant failure.
That said, its not just alcohol (ethanol) in the fuel that has caused the injector issues. These cars are OLD! The fuel has been laced with all sorts of other additives that change it as well, and we have seen the changes first hand on the dyno with BSFC values, power output, and efficiency. Aircooled engines with carburetors now want jetting thats 15% greater than it used to be for the same engine just a few years ago.
We can even tell a difference in how the fuel smells in the dyno cell, and now it gives us all a headache in 15 minutes in the text cell, no matter what kind of ventilation we employ. 10 years ago we could work in the cell and control room all day long and never experience this.
No, buying “ethanol free” doesn’t help. From what we’ve seen developing engines, and even fuel stabilizing additives (Driven Injector Defender, Carb Defender, and Storage Defender) it doesn’t really matter what fuel is chosen, it al sucks. For my personal cars l am now buying drums of the VP Vintage Unleaded, as l got so sick of all my carbureted cars needing the fuel systems redone every year. No matter what else l put into it, l still had issues.
It takes old fashioned, hands dirty diagnosis and a human brain to do this.
As far as the collateral damage not effecting “rebuild” from collateral damage... Well, that’s ONLY for our program where the original cylinders are removed with a huge CNC milling machine. The parent material above the cooling jacket is removed entirely, so the more that’s worn away, the less has to be machines. With my program all the things that see collateral damage from this mode of failure are thrown away, no matter if they are good, or bad. Again... These parts are thrown away even if they are in “perfect condition” at the time of disassembly. Why? We know they won’t last as long as the rest of the components that we are replacing, so reusing them is a compromise to save a few dolllars. You won’t find that here, anything that we have identified as a weakness in the platform at the time we complete an engine is replaced, and our base pricing for this includes 100% of these items in 100% of the cases.
Now, to someone who just replaces whats worn, and thats it (pretty much everyone else) the engine wold see extensive collateral damage if it suffered a cylinder scoring event, and resultant failure.
That said, its not just alcohol (ethanol) in the fuel that has caused the injector issues. These cars are OLD! The fuel has been laced with all sorts of other additives that change it as well, and we have seen the changes first hand on the dyno with BSFC values, power output, and efficiency. Aircooled engines with carburetors now want jetting thats 15% greater than it used to be for the same engine just a few years ago.
We can even tell a difference in how the fuel smells in the dyno cell, and now it gives us all a headache in 15 minutes in the text cell, no matter what kind of ventilation we employ. 10 years ago we could work in the cell and control room all day long and never experience this.
No, buying “ethanol free” doesn’t help. From what we’ve seen developing engines, and even fuel stabilizing additives (Driven Injector Defender, Carb Defender, and Storage Defender) it doesn’t really matter what fuel is chosen, it al sucks. For my personal cars l am now buying drums of the VP Vintage Unleaded, as l got so sick of all my carbureted cars needing the fuel systems redone every year. No matter what else l put into it, l still had issues.
#17
I have never had to add oil between oil changes and have not noticed a ticking/lifter sound that is prominent. I have often thought I heard a faint ticking sound but at times but never consistently and never long enough that I could trace it so I chalked it up to 996 paranoia.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
#18
Rennlist Member
The good news is that you have more info now, because ignorance doesn’t change reality.
My 996 makes some pretty nasty noises upon cold start, with about 61,000 miles. So my engine might be even worse than yours. But I still don’t worry about it, because there are options that range from cheap (roll the dice on a band-aide used engine), or spend $$$$ on a real nice rebuild. Either way, it’s happening one way or another, sooner or later.
Someone needs to make an electric conversion kit for these cars..
#19
I have never had to add oil between oil changes and have not noticed a ticking/lifter sound that is prominent. I have often thought I heard a faint ticking sound but at times but never consistently and never long enough that I could trace it so I chalked it up to 996 paranoia.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
#20
Former Vendor
I have never had to add oil between oil changes and have not noticed a ticking/lifter sound that is prominent. I have often thought I heard a faint ticking sound but at times but never consistently and never long enough that I could trace it so I chalked it up to 996 paranoia.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
This engine is the same way. It is injured, and it is failing. You may slow the progression of the cylinder scoring down some, and it may last a while. Certainly doing these things won’t hurt anything, and how much they help you’ll determine later.
That said, the new engine that you’ll build will need injectors anyway, so you’ll already have them. I am happy to help you nurse this along a bit, and when it starts to consume oil, l have a liquid “silver bullet” for you.
See ya Thursday :-)
#21
Rennlist Member
Looked familiar. This is from my engine at 98k miles (and that included a LOT of hard track miles over the years). The valve seat broke apart and you can see that had the chipping at the piston.
The car went on to 170k miles and continued track usage over the years until the engine blew up (wrist pin backed out apparently) and now sits in my garage waiting for a complete engine that I'll be sourcing soon. Just haven't had the funds to dump so much money into this project. It's sad really.
She was sure fun though the 13 years it lived.
The car went on to 170k miles and continued track usage over the years until the engine blew up (wrist pin backed out apparently) and now sits in my garage waiting for a complete engine that I'll be sourcing soon. Just haven't had the funds to dump so much money into this project. It's sad really.
She was sure fun though the 13 years it lived.
#22
I have never had to add oil between oil changes and have not noticed a ticking/lifter sound that is prominent. I have often thought I heard a faint ticking sound but at times but never consistently and never long enough that I could trace it so I chalked it up to 996 paranoia.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
The engine is on a lift table now and I don't currently have a stand to hold it so coming in from the sump isn't practical right now. Nor does it matter I guess because it won't reverse the diagnosis in any way. And here I thought I was just doing documentation to show a good condition when doing the ims replacement!
Looking forward to the knowledge gruppe class Thursday. Good timingi in an ironic way. The question I will have which maybe we can discuss Thursday night, I wasn't budgeting for an engine rebuild (probably no one ever does) this year. What is the risk to doing the other repairs, fixing/replacing the injectors and re-installing the engine to plan for rebuild next year? I usually put about 5K miles annually but its been quite a bit less lately as my motorcycle has taken priority on any kind of decent weather day.
#23
Racer
Sadly this post makes me cringe. About a month ago I noticed the tick tick sound. I thought, nah, it can’t be. Yesterday I heard the tick tick tick sound and puffs of white smoke out of one of the exhaust.
Now or I am curious about the liquid silver bullet.
Now or I am curious about the liquid silver bullet.
#24
Rennlist Member
Man, I don't know, if it was me I don't think I would rip into that motor. Sure you can see some marks but you have no idea how deep that scoring is. It doesn't use any oil, it doesn't make any noises, it isn't down on power, you don't have material in the oil, so basically it runs great. While I am new to these flat sixes, I have rebuilt a lot of motors - it is one of the things I enjoy more than anything. I have pulled plenty of motors apart that have marks in the cylinders like that and they run great and have for a long time. How long has that scoring been there? It could have been there for years. Is it possible that scoring could have been done from running the engine hard in cold weather before properly warming it up? Maybe I am missing something and will freely admit there are much smarter people than I in here, but I would at need at least some symptom that the motor is wounded before I spent the money rebuilding it.
Kudo's to Jake for offering to help the OP nurse it along a bit. I like the approach, similar to the Veterinarian who buys a race horse with a broken leg and nurses it back to 90% of its former glory, instead of just shooting it in the head and starting training another fold to race. Sometimes I enjoy nursing along an injured engine fixing the broken things just to see how long it will go!! lol
#25
Former Vendor
Man you make too much sense. It's not the Porsche way, you must exhaust all energy striving for perfection (even though it sometimes isn't practical or ever possible)..
Kudo's to Jake for offering to help the OP nurse it along a bit. I like the approach, similar to the Veterinarian who buys a race horse with a broken leg and nurses it back to 90% of its former glory, instead of just shooting it in the head and starting training another fold to race. Sometimes I enjoy nursing along an injured engine fixing the broken things just to see how long it will go!! lol
Kudo's to Jake for offering to help the OP nurse it along a bit. I like the approach, similar to the Veterinarian who buys a race horse with a broken leg and nurses it back to 90% of its former glory, instead of just shooting it in the head and starting training another fold to race. Sometimes I enjoy nursing along an injured engine fixing the broken things just to see how long it will go!! lol
We currently have 31 engines on the build board.. 19 of those are there due to bore scoring. Of those 7 are elective builds that haven’t failed yet, and the other 5 are a mix of other failures. Statistics don’t lie.
#27
"so why did you do a scope in first place? Did you suspect something?"
My clutch needed replaced. As preventative maintenance, I decided I would replace IMS, RMS, AOS, spark plugs/coils, coolant reservoir and a few other things. I ran diagnostics according to LN's recommendations with my Durametric (Minus the oil analysis and barometer since I was replacing the AOS anyway). I pulled the engine and transmission just to make it easier to do some of those items. As I was changing plugs, now that the engine is out, I scoped the cylinders with the goal of documenting that everything was ok at the time of doing all of this work. And now I have documented that not everything is ok.
I know no one can give me a guarantee that the engine won't blow up in another 1,000 miles. But we all live life making educated guesses based on probabilities. On one hand, I have the motor out but at the end of the day that's a couple days of my labor I waste if I put it back in, drive it a few thousand miles, and then have to take it back out again to rebuild. What i am more worried about is the probability that stalling for another 5,000 miles could double the cost of the rebuild. No guarantees, I understand, but it sounds like that is not likely. On the other hand, I'm not going to put the motor back in and just try and sell it on to someone who doesn't scope the engine. So it will get rebuilt and I think it sounds like a fun project to do the rebuild. So.. maybe I'll go to what may be the last knowledge gruppe hands on training this year and then I'll just have to decide if I dig out the funds to rebuild now or wait for a year and drive it.
My clutch needed replaced. As preventative maintenance, I decided I would replace IMS, RMS, AOS, spark plugs/coils, coolant reservoir and a few other things. I ran diagnostics according to LN's recommendations with my Durametric (Minus the oil analysis and barometer since I was replacing the AOS anyway). I pulled the engine and transmission just to make it easier to do some of those items. As I was changing plugs, now that the engine is out, I scoped the cylinders with the goal of documenting that everything was ok at the time of doing all of this work. And now I have documented that not everything is ok.
I know no one can give me a guarantee that the engine won't blow up in another 1,000 miles. But we all live life making educated guesses based on probabilities. On one hand, I have the motor out but at the end of the day that's a couple days of my labor I waste if I put it back in, drive it a few thousand miles, and then have to take it back out again to rebuild. What i am more worried about is the probability that stalling for another 5,000 miles could double the cost of the rebuild. No guarantees, I understand, but it sounds like that is not likely. On the other hand, I'm not going to put the motor back in and just try and sell it on to someone who doesn't scope the engine. So it will get rebuilt and I think it sounds like a fun project to do the rebuild. So.. maybe I'll go to what may be the last knowledge gruppe hands on training this year and then I'll just have to decide if I dig out the funds to rebuild now or wait for a year and drive it.
#28
Rennlist Member
I applaud you for being a stand-up person. The good news is that your level of documentation and thoroughness will command higher prices, accompanied by my opinion that the market will go up for these cars. What you will have in the end is far better than any PPI could deliver.
#29
Rennlist Member
We have gotten pretty good at nursing them along till we can work them in the schedule.. Some people use these cars as daily drivers with no other car, so when they have a failure they have to drive the car as long as they can. The bad scenarios are the catastrophic failures where nothing can be nursed and the car is an only vehicle.
We currently have 31 engines on the build board.. 19 of those are there due to bore scoring. Of those 7 are elective builds that haven’t failed yet, and the other 5 are a mix of other failures. Statistics don’t lie.
#30
Rennlist Member
Fuel trim won’t show injectors that leak down when an engine is hot. There’s no data that can be collected via OBDII that will.
It takes old fashioned, hands dirty diagnosis and a human brain to do this.
As far as the collateral damage not effecting “rebuild” from collateral damage... Well, that’s ONLY for our program where the original cylinders are removed with a huge CNC milling machine. The parent material above the cooling jacket is removed entirely, so the more that’s worn away, the less has to be machines. With my program all the things that see collateral damage from this mode of failure are thrown away, no matter if they are good, or bad. Again... These parts are thrown away even if they are in “perfect condition” at the time of disassembly. Why? We know they won’t last as long as the rest of the components that we are replacing, so reusing them is a compromise to save a few dolllars. You won’t find that here, anything that we have identified as a weakness in the platform at the time we complete an engine is replaced, and our base pricing for this includes 100% of these items in 100% of the cases.
Now, to someone who just replaces whats worn, and thats it (pretty much everyone else) the engine wold see extensive collateral damage if it suffered a cylinder scoring event, and resultant failure.
That said, its not just alcohol (ethanol) in the fuel that has caused the injector issues. These cars are OLD! The fuel has been laced with all sorts of other additives that change it as well, and we have seen the changes first hand on the dyno with BSFC values, power output, and efficiency. Aircooled engines with carburetors now want jetting thats 15% greater than it used to be for the same engine just a few years ago.
We can even tell a difference in how the fuel smells in the dyno cell, and now it gives us all a headache in 15 minutes in the text cell, no matter what kind of ventilation we employ. 10 years ago we could work in the cell and control room all day long and never experience this.
No, buying “ethanol free” doesn’t help. From what we’ve seen developing engines, and even fuel stabilizing additives (Driven Injector Defender, Carb Defender, and Storage Defender) it doesn’t really matter what fuel is chosen, it al sucks. For my personal cars l am now buying drums of the VP Vintage Unleaded, as l got so sick of all my carbureted cars needing the fuel systems redone every year. No matter what else l put into it, l still had issues.