Very interesting if you have m96 or m97 engine
Discussion
I found this very interesting ! I know alot of you may know about this already but i'm sure there are many that dont, so i thought i would share.
https://m.youtube.com/watch?v=hzUq2DFpeKw
https://m.youtube.com/watch?v=hzUq2DFpeKw
Great video, very informative.
Could this be a turning point for the 996/997.1?
13.30 The Solution: New patented Direct Oil Feed (DOF) - which shoots a stream of oil directly into the balls of the bearing.
Cost $800 for the kit, wonder if anyone is importing it yet.
Guess the question I have is does it solve the 'garage queen' issue caused by oil seeping through the bearing and into the shaft with lack of use?
Could this be a turning point for the 996/997.1?
13.30 The Solution: New patented Direct Oil Feed (DOF) - which shoots a stream of oil directly into the balls of the bearing.
Cost $800 for the kit, wonder if anyone is importing it yet.
Guess the question I have is does it solve the 'garage queen' issue caused by oil seeping through the bearing and into the shaft with lack of use?
It Looks like it may solve the 'garage queen' issue because like he said in the video it does seem to be happening more to cars that don't get used much or thrashed, but who knows, what i am worried about is mine is a driveway queen that i have owned for 5 years now and only average about 1000 miles a year so this has got me worried ! And i don't need a clutch yet as it had a new clutch about a year before i bought the car.
Edited by turk1 on Thursday 19th February 09:32
Edited by turk1 on Thursday 19th February 09:34
cook3471 said:
I already have one of these kits ready to go in on my 997.1 gt3 as I need a new clutch putting in before the sun starts to shine for me it's a small price to pay against what the cost of a engine build would be considering I have no porsche warranty
I didn't watch all of the youtube links and I am sure somebody may correct me but the GT3 engine is not known for having a problem with the IMS. Hopefully you haven't wasted your money.cook3471 said:
I already have one of these kits ready to go in on my 997.1 gt3 as I need a new clutch putting in before the sun starts to shine for me it's a small price to pay against what the cost of a engine build would be considering I have no porsche warranty
GT3 has the Mezger engine - different beast and pretty bulletproofedc said:
cook3471 said:
I already have one of these kits ready to go in on my 997.1 gt3 as I need a new clutch putting in before the sun starts to shine for me it's a small price to pay against what the cost of a engine build would be considering I have no porsche warranty
I didn't watch all of the youtube links and I am sure somebody may correct me but the GT3 engine is not known for having a problem with the IMS. Hopefully you haven't wasted your money.
So, we have this guy who says oil can run through a sealed bearing and turn to acid once heated up.
Hartech who say it's a cooling issue
Another specialist who blames fuel quality
Which is it guys?!
http://www.nnjr-pca.com/index.php?option=com_conte...
Hartech who say it's a cooling issue
Another specialist who blames fuel quality
Which is it guys?!
http://www.nnjr-pca.com/index.php?option=com_conte...
Edited by fastgerman on Thursday 19th February 11:04
fastgerman said:
So, we have this guy who says oil can run through a sealed bearing and turn to acid once heated up.
Hartech who say it's a cooling issue
After Hartech re-built my engine a couple of years ago (IMS bearing failure), they recommended that revs be kept above 2000rpm in normal driving. I could be wrong but I understood this to be to help keep oil thrashing through the bearing.Hartech who say it's a cooling issue
fastgerman said:
So, we have this guy who says oil can run through a sealed bearing and turn to acid once heated up.
Hartech who say it's a cooling issue
Another specialist who blames fuel quality
Which is it guys?!
http://www.nnjr-pca.com/index.php?option=com_conte...
I think you are mixing up different issues. The IMS bearing and bore scoring are independent of each other.Hartech who say it's a cooling issue
Another specialist who blames fuel quality
Which is it guys?!
http://www.nnjr-pca.com/index.php?option=com_conte...
Edited by fastgerman on Thursday 19th February 11:04
This is what Porsche did for me under warranty following this:
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Friday 16th August 2013
Okay, so on the topic of how long will I keep my car, I have requested and been sent the warranty information since ownership
Replace rear main seal
Replace slave cylinder
Replace Intermediate Shaft incl shaft sealing ring, pan-head screw x 8, screw x 6, pan-head screw x 12, housing, o-ring, hexagon-head bolt x 3, hexagon nut, sealing ring x 2, aluminium sealing ring, clutch operating.
Replaced OSR window seal
Replaced coil packs incl. gasket and 6 x ignition coils
Gearbox
Setup
Front strut
Health check
Vibration damper, hexagon nut x 3, hexagon nut, pan-head screw x 2, replacement t?, pan-head screw x 12, lock nut, hexagon nut.
Porsche Guildford then advised:
‘I have checked with Joe the technician who worked on your car and he confirmed that what we replaced was the failed and leaking items which are the common faults. There is absolutely no need to replace the shaft. I hope this helps.’
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Friday 16th August 2013
Okay, so on the topic of how long will I keep my car, I have requested and been sent the warranty information since ownership
Replace rear main seal
Replace slave cylinder
Replace Intermediate Shaft incl shaft sealing ring, pan-head screw x 8, screw x 6, pan-head screw x 12, housing, o-ring, hexagon-head bolt x 3, hexagon nut, sealing ring x 2, aluminium sealing ring, clutch operating.
Replaced OSR window seal
Replaced coil packs incl. gasket and 6 x ignition coils
Gearbox
Setup
Front strut
Health check
Vibration damper, hexagon nut x 3, hexagon nut, pan-head screw x 2, replacement t?, pan-head screw x 12, lock nut, hexagon nut.
Porsche Guildford then advised:
‘I have checked with Joe the technician who worked on your car and he confirmed that what we replaced was the failed and leaking items which are the common faults. There is absolutely no need to replace the shaft. I hope this helps.’
edc said:
fastgerman said:
So, we have this guy who says oil can run through a sealed bearing and turn to acid once heated up.
Hartech who say it's a cooling issue
Another specialist who blames fuel quality
Which is it guys?!
http://www.nnjr-pca.com/index.php?option=com_conte...
I think you are mixing up different issues. The IMS bearing and bore scoring are independent of each other.Hartech who say it's a cooling issue
Another specialist who blames fuel quality
Which is it guys?!
http://www.nnjr-pca.com/index.php?option=com_conte...
Edited by fastgerman on Thursday 19th February 11:04
Looking at this picture:
It would suggest that if the bearing was indeed, subject to oil acid, started deteriorating, then this would upset the balance of the ims and cause uneven bore wear?
Again, this could be complete b0110ck5
heads off to look at cheap 996 C2! As a matter of policy we do not normally respond where other "experts" explain their issues - trying to combat what we may disagree with by positive responses rather than negative criticism.
However when our name, technical expertise and solutions are mentioned in posts we feel we sometimes have to put our point of view across - as now. This is not intended to counteract all of the points in the video but simply to give another point of view for your consideration. We support anyone that tries to help owners with problems created by manufacturers who then do not solve them for their customers and support all genuine attempts at solutions - as this obviously is. However I do have one important criticism that I am somewhat reluctant to post but feel I have to.
A ball bearing does not require oil under pressure to work and pressure makes no difference as long as flow is sufficient. What it needs is recirculating fresh cool oil to wash out minute debris particles and maintain lubrication (and I think we all agree on that).
The type of oil pump used in these engines is quite basic and the delivery rate is low at low revs but typical of the design can easily manage good oil pressure once the revs rise. We would be reluctant to do anything that reduces oil pressure to the cranks and camshaft area at tickover and low revs driving (which most cars spend most of their life doing according to the datalogs) although the oil delivery hole diameter in this product is so small I doubt it makes a lot of difference..
The early double row bearing specs out at slightly less load bearing than the single row because the track for the balls is shallower - so the single row bearing should be just as good (or possibly slightly better).
Both bearings have the same inside and outside diameter and the double row is slightly wider so can be replaced with the single row and spacers.
The double row was special made for Porsche and when we contacted the original manufacturers for supply over a decade ago - they supplied us with their last remaining stock which we used for a while but eventually dried. I suspect we were the only people discussing this issue with the original manufacturer as I know we were the only ones they supplied their last remaining stock to.
While questioning the choice of using the double row bearing with the engineer at the original manufacturers - they agreed with us that it was not their advised good practice to fit lip seals and fill with grease in an oil environment and supported our conclusion that it would be better to remove them as the oil would always eventually wash out the grease and then have insufficient flow to lubricate the bearing reliably.
In manufacturing there are other considerations like the problem of stocking bearings and pre-assembled shafts without protecting the bearings from condensation and dust and I don't know if this was a factor in the decision.
We felt that the grease filled bearing would initially get contaminated by the small particles of metal that are always ground away during running in a bearing and particularly the specification and grade of bearing used but it took stripping and replacing bearings in a great many shafts before we came across some just at the right point to confirm our theory showing the grease left and metal particles mixed and resembling fine grinding paste. Others had washed out the grease and remained with some oil inside.
The bearings chosen have relatively thin outer casings and are fitted with an interference fit into the shaft. Interference fits need tolerances and sometimes you get a very big bearing fitted into a very tight hole and that changes the fit inside the bearing and wear the balls during running in more than others.
Some that we replaced had cracked the hard outer bearing cage with long typically metal fatigue polished fracture lines that can only come about due to the balls running too tight in the cage (until they had worn down - creating the debris and the grinding paste scenario). All the others had oil in them despite failing.
So we too decided that the problem was probably caused mainly by the seals and thought about how to introduce fresh clean cooler filtered oil to the bearing.
We also thought that if we were right - the relatively small failure percentages would mean that some (probably that were too tight in the original fit) could create too much "grinding paste" and wear the balls away too much and fail prematurely whereas those with the right fit might survive long enough to gradually wear through the seal edge (which is more properly described as a dust seal or shroud) after which the grease and debris must be being replaced by the oil and that they then might last very much longer.
The passage of time has proven this theory as they either seem to fail around 25 to 45 K or last to well over 100K (although there will always be the odd exception).
If the problem was acid corrosion why would those lasting much longer not suffer more?
Let's get back to the salient issue. We both agree that the problem is the seals and that there is a need for fresh oil to lubricate the bearing.
The product advertised does this and I have no problem about anyone wanting to fit it and use it and commend the team that developed and manufactured it - if they genuinely thought that was the only solution.
I also agree that a lot of mis-information is trawled on the Internet and that many contributors do not have the technical background to provide the reliable information they post and can mislead others and of course commercial pressures make others promote solutions with technical descriptions that are completely wrong - to sell the product to an unsuspecting market.
So what do we disagree about?
The spinning of the bearing to demonstrate that centrifugal force could spin out the oil is correct - but begs the question - how do the others survive to over 100K and how do all other ball bearing shafts in gearboxes and other rotating applications over a century of wide use last if the rotation of the bearing evacuates all the oil and also how does the oil get in the bearing in the first place to become spun out?
The answer is very simple - it is not just the bearing that is rotating and whatever it is connected to is also rotating (and usually at a larger diameter) and this is both throwing oil in all directions and creating an oil mist inside the chamber that continually replaces the oil being displaced by the rotation of the bearing.
Describing just the bearing mysteriously full of oil to start with spinning it out under rotation without considering what else is going on seems to me a serious omission of logic and a weak technical explanation especially when in this case there is an addition factor - the linear movement of the chain which is immersed in an oil bath right next to the IMS and travelling at great speed splashing oil in all directions with great force.
The diameter of the chain gear sprocket is around 3 times the diameter of the bearing and centrifugal force increases with the square of the radius so the effect of the sprocket throwing oil around is to provide a force around 9 times greater than that of the bearing trying to expel it - and this is in principle why ball bearings work so well in most oil filled applications.
With the engine running at say 3500 rpm the IMS is running at 2310 rpm and at the chain diameter the chain is moving at a linear speed of 1 ft/rev or 2310ft/min = 138600 ft/hour = 26mph (52mph @7000 rpm).
Can you imagine how much the oil in the oil bath next to the IMS bearing is being thrown in all directions by a sprocket and chain at those sorts of speeds and it is difficult to see why that does not provide sufficient oil supply to the open bearing to satisfy its requirements.
It also explains why for racing there seems less of a problem because the revs used increase the oil supply and reduce the chock loading affect of chain snatch at low revs. Furthermore it also explains why those bearings that survive past say 45K say continue to work well up to over 100 K since enough oil is then "thrown" at the slightly worn seal to enter and exit it - but how much better would it be with the seal removed.
So our general conclusion was that the bearing is anyway a little small for the shock loads created by a chain with hydraulic tensioners anyway - sort of borderline - but in most cases will last OK if the oil seal is removed or a standard bearing is replaced without the oil seal.
it is not the best solution anyway and the bearings will always be borderline small regardless of their construction, type or cost.
We replace them with the same standard bearing with the seals removed and therefore no oil is trapped in the shaft (as it is spun out when the engine is running) and only fills at standstill with the fresh oil in the engine. We choose a bearing with a fit that allows more variation for the interference fit to try and eliminate that problem where a build up of tolerances (or problems during assembly) can cause.
The larger upgrade bearing has a very much thicker outer cage that resists the squeeze put on by the interference fit better and generally has caused no problems - but in our opinion - better with the seal removed .
All this does not mean that the product described in the video will not work nor that it will not provide fresh oil to the bearing - so if you can afford it I see no reason not to fit it - if you want to.
However I think on the balance of probability the omission of the corresponding explanation about the actual source of what we consider to be a alternative perfectly adequate source of a fresh oil supply may influence them in weighing up what to do for the best.
If the engine is being rebuilt it can be fitted with the later shaft with the bigger bearing (except earlier roller chain examples for which we will soon be manufacturing our own shaft - prototype already tested over 3 years of racing) or with the std. bearing seal removed etc or in the car the bearing seal can be removed or the bearing replaced.
There are also roller bearing alternatives available elsewhere but the fact that despite the problems the grease filled bearings experience in their early life - if those that survive can last so long thereafter despite having a seal shield (slightly worn) still in place - suggests that it would not take much of an improvement in the oil supply to do as much as is possible in the circumstances - but it is your choice!
Baz
However when our name, technical expertise and solutions are mentioned in posts we feel we sometimes have to put our point of view across - as now. This is not intended to counteract all of the points in the video but simply to give another point of view for your consideration. We support anyone that tries to help owners with problems created by manufacturers who then do not solve them for their customers and support all genuine attempts at solutions - as this obviously is. However I do have one important criticism that I am somewhat reluctant to post but feel I have to.
A ball bearing does not require oil under pressure to work and pressure makes no difference as long as flow is sufficient. What it needs is recirculating fresh cool oil to wash out minute debris particles and maintain lubrication (and I think we all agree on that).
The type of oil pump used in these engines is quite basic and the delivery rate is low at low revs but typical of the design can easily manage good oil pressure once the revs rise. We would be reluctant to do anything that reduces oil pressure to the cranks and camshaft area at tickover and low revs driving (which most cars spend most of their life doing according to the datalogs) although the oil delivery hole diameter in this product is so small I doubt it makes a lot of difference..
The early double row bearing specs out at slightly less load bearing than the single row because the track for the balls is shallower - so the single row bearing should be just as good (or possibly slightly better).
Both bearings have the same inside and outside diameter and the double row is slightly wider so can be replaced with the single row and spacers.
The double row was special made for Porsche and when we contacted the original manufacturers for supply over a decade ago - they supplied us with their last remaining stock which we used for a while but eventually dried. I suspect we were the only people discussing this issue with the original manufacturer as I know we were the only ones they supplied their last remaining stock to.
While questioning the choice of using the double row bearing with the engineer at the original manufacturers - they agreed with us that it was not their advised good practice to fit lip seals and fill with grease in an oil environment and supported our conclusion that it would be better to remove them as the oil would always eventually wash out the grease and then have insufficient flow to lubricate the bearing reliably.
In manufacturing there are other considerations like the problem of stocking bearings and pre-assembled shafts without protecting the bearings from condensation and dust and I don't know if this was a factor in the decision.
We felt that the grease filled bearing would initially get contaminated by the small particles of metal that are always ground away during running in a bearing and particularly the specification and grade of bearing used but it took stripping and replacing bearings in a great many shafts before we came across some just at the right point to confirm our theory showing the grease left and metal particles mixed and resembling fine grinding paste. Others had washed out the grease and remained with some oil inside.
The bearings chosen have relatively thin outer casings and are fitted with an interference fit into the shaft. Interference fits need tolerances and sometimes you get a very big bearing fitted into a very tight hole and that changes the fit inside the bearing and wear the balls during running in more than others.
Some that we replaced had cracked the hard outer bearing cage with long typically metal fatigue polished fracture lines that can only come about due to the balls running too tight in the cage (until they had worn down - creating the debris and the grinding paste scenario). All the others had oil in them despite failing.
So we too decided that the problem was probably caused mainly by the seals and thought about how to introduce fresh clean cooler filtered oil to the bearing.
We also thought that if we were right - the relatively small failure percentages would mean that some (probably that were too tight in the original fit) could create too much "grinding paste" and wear the balls away too much and fail prematurely whereas those with the right fit might survive long enough to gradually wear through the seal edge (which is more properly described as a dust seal or shroud) after which the grease and debris must be being replaced by the oil and that they then might last very much longer.
The passage of time has proven this theory as they either seem to fail around 25 to 45 K or last to well over 100K (although there will always be the odd exception).
If the problem was acid corrosion why would those lasting much longer not suffer more?
Let's get back to the salient issue. We both agree that the problem is the seals and that there is a need for fresh oil to lubricate the bearing.
The product advertised does this and I have no problem about anyone wanting to fit it and use it and commend the team that developed and manufactured it - if they genuinely thought that was the only solution.
I also agree that a lot of mis-information is trawled on the Internet and that many contributors do not have the technical background to provide the reliable information they post and can mislead others and of course commercial pressures make others promote solutions with technical descriptions that are completely wrong - to sell the product to an unsuspecting market.
So what do we disagree about?
The spinning of the bearing to demonstrate that centrifugal force could spin out the oil is correct - but begs the question - how do the others survive to over 100K and how do all other ball bearing shafts in gearboxes and other rotating applications over a century of wide use last if the rotation of the bearing evacuates all the oil and also how does the oil get in the bearing in the first place to become spun out?
The answer is very simple - it is not just the bearing that is rotating and whatever it is connected to is also rotating (and usually at a larger diameter) and this is both throwing oil in all directions and creating an oil mist inside the chamber that continually replaces the oil being displaced by the rotation of the bearing.
Describing just the bearing mysteriously full of oil to start with spinning it out under rotation without considering what else is going on seems to me a serious omission of logic and a weak technical explanation especially when in this case there is an addition factor - the linear movement of the chain which is immersed in an oil bath right next to the IMS and travelling at great speed splashing oil in all directions with great force.
The diameter of the chain gear sprocket is around 3 times the diameter of the bearing and centrifugal force increases with the square of the radius so the effect of the sprocket throwing oil around is to provide a force around 9 times greater than that of the bearing trying to expel it - and this is in principle why ball bearings work so well in most oil filled applications.
With the engine running at say 3500 rpm the IMS is running at 2310 rpm and at the chain diameter the chain is moving at a linear speed of 1 ft/rev or 2310ft/min = 138600 ft/hour = 26mph (52mph @7000 rpm).
Can you imagine how much the oil in the oil bath next to the IMS bearing is being thrown in all directions by a sprocket and chain at those sorts of speeds and it is difficult to see why that does not provide sufficient oil supply to the open bearing to satisfy its requirements.
It also explains why for racing there seems less of a problem because the revs used increase the oil supply and reduce the chock loading affect of chain snatch at low revs. Furthermore it also explains why those bearings that survive past say 45K say continue to work well up to over 100 K since enough oil is then "thrown" at the slightly worn seal to enter and exit it - but how much better would it be with the seal removed.
So our general conclusion was that the bearing is anyway a little small for the shock loads created by a chain with hydraulic tensioners anyway - sort of borderline - but in most cases will last OK if the oil seal is removed or a standard bearing is replaced without the oil seal.
it is not the best solution anyway and the bearings will always be borderline small regardless of their construction, type or cost.
We replace them with the same standard bearing with the seals removed and therefore no oil is trapped in the shaft (as it is spun out when the engine is running) and only fills at standstill with the fresh oil in the engine. We choose a bearing with a fit that allows more variation for the interference fit to try and eliminate that problem where a build up of tolerances (or problems during assembly) can cause.
The larger upgrade bearing has a very much thicker outer cage that resists the squeeze put on by the interference fit better and generally has caused no problems - but in our opinion - better with the seal removed .
All this does not mean that the product described in the video will not work nor that it will not provide fresh oil to the bearing - so if you can afford it I see no reason not to fit it - if you want to.
However I think on the balance of probability the omission of the corresponding explanation about the actual source of what we consider to be a alternative perfectly adequate source of a fresh oil supply may influence them in weighing up what to do for the best.
If the engine is being rebuilt it can be fitted with the later shaft with the bigger bearing (except earlier roller chain examples for which we will soon be manufacturing our own shaft - prototype already tested over 3 years of racing) or with the std. bearing seal removed etc or in the car the bearing seal can be removed or the bearing replaced.
There are also roller bearing alternatives available elsewhere but the fact that despite the problems the grease filled bearings experience in their early life - if those that survive can last so long thereafter despite having a seal shield (slightly worn) still in place - suggests that it would not take much of an improvement in the oil supply to do as much as is possible in the circumstances - but it is your choice!
Baz
Thanks Baz for your detailed post, can i just ask you how worried i should be with my 996/2 3.6 engine having this problem which has now reach 52000 miles, but does sit about for weeks at a time without been used and i have only averaged about 1000 miles a year for the past 5 years, when i do use it i do take it out for long runs and do make sure i keep it below 3rpm until it has warmed up, i just don't know what to do for the best !
cook3471 said:
I already have one of these kits ready to go in on my 997.1 gt3 as I need a new clutch putting in before the sun starts to shine for me it's a small price to pay against what the cost of a engine build would be considering I have no porsche warranty
Strange go to their web site and it says excluding Turbo GT2 GT3 and Carrera GT see the 1st paragraph down
hartech said:
but it is your choice!
Baz
Hi Baz,Baz
Great response and very detailed.
I was sent an email from Grant a while ago advising of new Hartech products for engine maintenance.
A lot of owners hold the Hartech name in high regard, as do I, especially when the Peter Morgan inspection website (http://www.porscheinspections.com/qanda.php) quotes your work.
The following quotes I also like:
Re:IMS - 'This issue would not stop me buying a car, if it was otherwise on the button. Many independent specialists now offer strengthened IMS bearings to retrofit. Replacement at clutch change time reduces the relative labour cost involved and can improve the desirability of a car at resale.'
Re:Bore scoring - 'These failures are real, but we must emphasise that they are a relatively low percentage of all the Carrera engine Porsches out there. More than a few reputable independent dealers I have spoken to say that they haven't seen a bore scored 996/997/Boxster or Cayman for years (and that is only partly down to their expertise). It should not put you off buying one of these cars, assuming you do your homework and know the obvious failure signs.'
So, my question:
For 996 and 997.1 engines which appear to be fine, not using any oil etc. What parts do you recommend fitting for the cars to last many more years on a mixed variety of driving?
Thanks
2005 997 Carrera S owner with 48k miles and out of warranty :-)
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