LN Eng retrofit post mortem
#1
Racer
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Can someone direct me to data showing bearing wear and function versus miles after LN Eng retrofit installation?
If your m96 has the 13mm IMS bearing nut you can inspect or replace your retrofit bearing (as is now being suggested) for ~$3000 per visit. Might as well do RMS while you are in there.
On the other hand, if you are considering using the LN Eng hybrid bearing as part of your reman or >MY05 rebuild (22mm IMS bearing nut) you will want this data first as bearing inspection would be prohibitively expensive. Unless you are okay with R&I plus tear down every 40,000 miles.
If your m96 has the 13mm IMS bearing nut you can inspect or replace your retrofit bearing (as is now being suggested) for ~$3000 per visit. Might as well do RMS while you are in there.
On the other hand, if you are considering using the LN Eng hybrid bearing as part of your reman or >MY05 rebuild (22mm IMS bearing nut) you will want this data first as bearing inspection would be prohibitively expensive. Unless you are okay with R&I plus tear down every 40,000 miles.
#2
Former Vendor
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What exactly are you looking for? I can't really grasp from your post what "data" you require.
The elective 40K mile bearing swap has been recommended by LN for a substantial period of time now- it is nothing new.
The elective 40K mile bearing swap has been recommended by LN for a substantial period of time now- it is nothing new.
#3
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I am looking for operational life data for the hybrid bearing. I would assume that before the retrofit went into production data was collected to calculate MTBF.
It is my understanding that a sealed bearing was selected by Porsche because of inadequate oil supply to the IMS bearing area. I also understand that this sparse oiling was taken into account during the hybrid bearing selection process. Perhaps we have a mechanical engineer or SAE person who can comment on what tests, metrics and qualification processes are industry standard for critical bearing applications.
It is my understanding that a sealed bearing was selected by Porsche because of inadequate oil supply to the IMS bearing area. I also understand that this sparse oiling was taken into account during the hybrid bearing selection process. Perhaps we have a mechanical engineer or SAE person who can comment on what tests, metrics and qualification processes are industry standard for critical bearing applications.
#4
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I carried out the majority of tests for LN on this and supplied the data to them. There was also no less than three bearing engineers involved with this. I have utilized the same hybrid bearing technology in EVERY ONE of my engines since the beginning of my engine program and have a 100% effectiveness rating with them.
Prior to the IMS retrofit being possible this same bearing technology was used in the IMS Updates for completely torn down engines that we reconstructed.
LN has the data that you desire, whether they feel that your request for it is worthy of release of is up to them.
Remember, Porsche Engineers designed this bearing and the associated issues. Do all the calculations and tests that you want, the results of the IMSR are speaking for themselves. Many of them have more than 40K miles, I put over 30K on the very first IMSR ever carried out in one year alone. That engine is still going strong.
Contact LN.
Prior to the IMS retrofit being possible this same bearing technology was used in the IMS Updates for completely torn down engines that we reconstructed.
LN has the data that you desire, whether they feel that your request for it is worthy of release of is up to them.
Remember, Porsche Engineers designed this bearing and the associated issues. Do all the calculations and tests that you want, the results of the IMSR are speaking for themselves. Many of them have more than 40K miles, I put over 30K on the very first IMSR ever carried out in one year alone. That engine is still going strong.
Contact LN.
#6
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Not sure I understand what data you're looking for.
As somebody who has nothing to sell, to gain or to lose from anybody choosing to worry about the IMS bearing, let me also tell you that I'm driving an original bearing'ed 159k mile 996, which is my 3rd with over 90k miles (all on original bearings).
Also replaced a "perfect" factory bearing for somebody else. Through my work with other shops, I've seen 3 failed 996 motors (i'm seeking them out, and it's been somewhat rare to find one), none of them were an IMS issue. Also from my experience, I'd recommend a car that had a factory re-man'd engine, since the most likely issues w/these cars will not be catastrophic, instead things like AOS, starter, alternator, hoses, etc. will need replacement over time, which are all updated and newer in the case of an updated motor.
As somebody who has nothing to sell, to gain or to lose from anybody choosing to worry about the IMS bearing, let me also tell you that I'm driving an original bearing'ed 159k mile 996, which is my 3rd with over 90k miles (all on original bearings).
Also replaced a "perfect" factory bearing for somebody else. Through my work with other shops, I've seen 3 failed 996 motors (i'm seeking them out, and it's been somewhat rare to find one), none of them were an IMS issue. Also from my experience, I'd recommend a car that had a factory re-man'd engine, since the most likely issues w/these cars will not be catastrophic, instead things like AOS, starter, alternator, hoses, etc. will need replacement over time, which are all updated and newer in the case of an updated motor.
#7
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Last year we saw more water pump related failures kill engines than the IMS... 13 cars in a row to be exact.. Today we just has an AOS failure kill one. The IMS is the most widely known mode of failure, but far from the only one.
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#8
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At least parts are available for Porsche... good thing.
#10
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You guys are worrying entirely too much, honestly. It's one of the most reliable platforms I've been around. Properly maintained, I haven't thought twice about driving mine cross country, doing time trials in them, and driving them back...
#11
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#12
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The AOS can fail in at least two different ways..
One of these does NOT cause the engine to smoke. The diaphragm fails and creates a crankcase vacuum that can pull oil away from the oil pick up tube and create an oil starvation issue. This creates low oil volume and pressure which killed the #1 main bearing and #3 and #6 rod bearings of one engine that we just diagnosed yesterday. That engine never smoked when the AOS failed at all, it just would not idle. A few days after the AOS was found bad the engine gained a rod knock and then effectively died.
We have seen this same trait many times over from this particular mode of AOS failure. I experienced this mode of failure from one of my own stock engines in a Boxster in 2009.
The water pump failure isn't what kills the engine... Its the secondary damage from broken impeller blades that silently circulate in the cooling system until they find a passage in a cylinder head to obstruct. The 2000 and 2001 engines have the smallest capillaries in the heads and these failures occur to them in much greater numbers than any other engine. When this passage is obstructed a very small portion of the head gains a "hot spot" and then a crack occurs.. Since this area has coolant and oil passages near each other the crack intsersects them and creates intermix. This intermix creates foamy oil and this can easily kill every bearing within the engine and even the cylinders.
These are a couple of ways how the simplest of failures can cost you a complete engine. The moral of the story is to ELECTIVELY change the water pump every 3 years (no matter the milage) and the AOS at the same time.
Perhaps since we have been working with these engines and their failures longer than anyone we are exposed to the majority of them. Who knows, but it certainly is real under this roof and we have documented EVERY failure we have seen..
One of these does NOT cause the engine to smoke. The diaphragm fails and creates a crankcase vacuum that can pull oil away from the oil pick up tube and create an oil starvation issue. This creates low oil volume and pressure which killed the #1 main bearing and #3 and #6 rod bearings of one engine that we just diagnosed yesterday. That engine never smoked when the AOS failed at all, it just would not idle. A few days after the AOS was found bad the engine gained a rod knock and then effectively died.
We have seen this same trait many times over from this particular mode of AOS failure. I experienced this mode of failure from one of my own stock engines in a Boxster in 2009.
The water pump failure isn't what kills the engine... Its the secondary damage from broken impeller blades that silently circulate in the cooling system until they find a passage in a cylinder head to obstruct. The 2000 and 2001 engines have the smallest capillaries in the heads and these failures occur to them in much greater numbers than any other engine. When this passage is obstructed a very small portion of the head gains a "hot spot" and then a crack occurs.. Since this area has coolant and oil passages near each other the crack intsersects them and creates intermix. This intermix creates foamy oil and this can easily kill every bearing within the engine and even the cylinders.
These are a couple of ways how the simplest of failures can cost you a complete engine. The moral of the story is to ELECTIVELY change the water pump every 3 years (no matter the milage) and the AOS at the same time.
Perhaps since we have been working with these engines and their failures longer than anyone we are exposed to the majority of them. Who knows, but it certainly is real under this roof and we have documented EVERY failure we have seen..
#13
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Jake, thanks for the clarifications.
I honestly never heard of the AOS failure you described. It's good to know the symptom (not idling?).
I'll keep in mind the 3 yr replacement cycle for both AOS and water pump.
I honestly never heard of the AOS failure you described. It's good to know the symptom (not idling?).
I'll keep in mind the 3 yr replacement cycle for both AOS and water pump.
#15
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These engines are stronger than you think....