How widespread is the RMS problem???
07-21-2004, 07:15 PM
#1
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How widespread is the RMS problem???
There are three 996s for sale at my local Porsche dealer. There's an '02 C4S that had its engine replaced because of RMS, and there's an '01 that had the seal replaced. Although both problems were covered under warranty, the owners decided to sell. It would be interesting to find out just how many 996s have been affected by this issue. There's certainly a lot of posters on this Board who have had the problem.
07-21-2004, 10:59 PM
#3
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The 996 with the new rebuilt engine might be a very good deal. I have seen no data that would support the premise that a brand new engine is better in any way, but some people think it is, lowering the value. I am personally very curious as to whether there are changes in the 997 that address drivetrain reliability.
07-21-2004, 11:06 PM
#4
Three Wheelin'
I don't think the RMS issue is a big deal.
I have looked very closely at this RMS issue, and tend to believe that other than it being an annoyance of oil on the floor, the negative aspects of either a leaky RMS or Intermediate Shaft seal are nil. The way they leak ("weep" is a better term) there is only the most remote chance that the flywheel, clutch plate or pressure plate will become oil damaged. While it is better that the seals not leak, a car with a leaky seal is just as reliable in all other aspects. Main Seals leak on many types of engines, not just the 996 and 986 engines, and they very rarely lead to engine failure. If the engine does fail, it is usually because of some other issue.
There is not one recorded incident where a 996 engine has failed because of a leaky RMS or IS seal. Lots of engines have been replaced because of leaky seals more as a PR effort to address customer dissatisfaction, but those cars with new engines are not any more reliable than the cars with the old engines.
There is not one recorded incident where a 996 engine has failed because of a leaky RMS or IS seal. Lots of engines have been replaced because of leaky seals more as a PR effort to address customer dissatisfaction, but those cars with new engines are not any more reliable than the cars with the old engines.
07-22-2004, 07:46 AM
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I have looked very closely at this RMS issue, and tend to believe that other than it being an annoyance of oil on the floor, the negative aspects of either a leaky RMS or Intermediate Shaft seal are nil.
Main Seals leak on many types of engines, not just the 996 and 986 engines,
I have owned numerous cars over the last fourty years and have driven almost a million miles. I've owned anything from a Mercury Commet to a Ferrari 360. A Toyota Corolla that I owned had close to 250K miles when I sold it. All the cars that I've owned had one thing in common: none of them leaked oil, not even a trace. All of my cars were garraged and I've never had a trace of oil on my garrage floor.
From a mechanical point of view I can't disagree with your assessment. Having a car that leaks oil however is not only an annoyance but also an embarassment. I can't imagine paying $90K for a car and then simply dismissing the fact that it leaks oil just like a teenager's $500 clunker.
Main Seals leak on many types of engines, not just the 996 and 986 engines,
I have owned numerous cars over the last fourty years and have driven almost a million miles. I've owned anything from a Mercury Commet to a Ferrari 360. A Toyota Corolla that I owned had close to 250K miles when I sold it. All the cars that I've owned had one thing in common: none of them leaked oil, not even a trace. All of my cars were garraged and I've never had a trace of oil on my garrage floor.
From a mechanical point of view I can't disagree with your assessment. Having a car that leaks oil however is not only an annoyance but also an embarassment. I can't imagine paying $90K for a car and then simply dismissing the fact that it leaks oil just like a teenager's $500 clunker.
07-22-2004, 08:28 AM
#6
Three Wheelin'
If your engine fails it is too costly to investigate why it failed. In most cases Porsche just send it back to the factory to be rebuilt and you never get to know what the cause was.
The engine can self destruct for several reasons. I can only comment on why an engine can lead to catastrophic failure because of a leaking RMS.
The seal fails because the whole in which it fits has become oval by a few thou of an inch, enough
to allow oil to seep through it. The engine block in which the crankshaft sits within the seal is made from a porus aluminium material which is designed to absorb fluctual thermal changes and reduce mechanical noise. This material used in the block construction allows it expand and shrink with fluctuations in engine temperature. The deisign has a flaw because it can lead to warping in the material. This can cause problems elsewhere in the engine but in regards to the RMS, it can lead to an ovaling of the bore in the engine block where the seal fits. The result is that oil can either A) seep between the seal and the crank case or B) between the seal and the crankshaft. In the latter case it can lead to concentric wobble of the crankshaft. This eventually makes the leak worse. And of course the crankshaft should not wobble for obvious reasons.
If the seal fails and is left unattended it can lead to several serious problems.
Here are but to mention a few:
Loss of oil pressure.
Damage to the crankshaft.
Damage to the crankshaft bearing.
Damage to the cylinder bores due to scoring from a misaligned crankshaft.
Damage to the clutch (from oil contamination)
Damage to the transmission (from concentric wobble at the clutch/flywheel due to crankshaft wobble)
PAG are aware of the RMS problem and that is why they have tried several seal types. The fault is with the engine block and not the seal. They have recently started to use a new engine block. I have heard rumours that this has fixed the problem but only time will tell.
In most cases, replacing the seal will fix the problem. Especially if the seal fails in the scenario as described for (A) above. Because the seal is rubber it has some play to "mould" into the crank case bore opening. So sometimes replacing the seal will fix the problem. However, many have to be replaced several times over and its a costly repair if you are out of warranty. And you can't just live with a leaking RMS for all the reasons described above. Simply saying it's just a leak is not acceptable for this latent defect that is the result of a manufacturing flaw.
The engine can self destruct for several reasons. I can only comment on why an engine can lead to catastrophic failure because of a leaking RMS.
The seal fails because the whole in which it fits has become oval by a few thou of an inch, enough
to allow oil to seep through it. The engine block in which the crankshaft sits within the seal is made from a porus aluminium material which is designed to absorb fluctual thermal changes and reduce mechanical noise. This material used in the block construction allows it expand and shrink with fluctuations in engine temperature. The deisign has a flaw because it can lead to warping in the material. This can cause problems elsewhere in the engine but in regards to the RMS, it can lead to an ovaling of the bore in the engine block where the seal fits. The result is that oil can either A) seep between the seal and the crank case or B) between the seal and the crankshaft. In the latter case it can lead to concentric wobble of the crankshaft. This eventually makes the leak worse. And of course the crankshaft should not wobble for obvious reasons.
If the seal fails and is left unattended it can lead to several serious problems.
Here are but to mention a few:
Loss of oil pressure.
Damage to the crankshaft.
Damage to the crankshaft bearing.
Damage to the cylinder bores due to scoring from a misaligned crankshaft.
Damage to the clutch (from oil contamination)
Damage to the transmission (from concentric wobble at the clutch/flywheel due to crankshaft wobble)
PAG are aware of the RMS problem and that is why they have tried several seal types. The fault is with the engine block and not the seal. They have recently started to use a new engine block. I have heard rumours that this has fixed the problem but only time will tell.
In most cases, replacing the seal will fix the problem. Especially if the seal fails in the scenario as described for (A) above. Because the seal is rubber it has some play to "mould" into the crank case bore opening. So sometimes replacing the seal will fix the problem. However, many have to be replaced several times over and its a costly repair if you are out of warranty. And you can't just live with a leaking RMS for all the reasons described above. Simply saying it's just a leak is not acceptable for this latent defect that is the result of a manufacturing flaw.
07-22-2004, 10:57 AM
#7
Professor of Pending Projects
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"...They have recently started to use a new engine block. I have heard rumours that this has fixed the problem but only time will tell...."
Do you have proof of this change? Was this done for the recent production of 996 or for the 997?
This issue has been the only thing keeping me for getting a 996 C4S and having to go with a GT3. As the GT3 will be a better car to keep for many many years without the worries of the regular 996 engines and transmissions.
Do you have proof of this change? Was this done for the recent production of 996 or for the 997?
This issue has been the only thing keeping me for getting a 996 C4S and having to go with a GT3. As the GT3 will be a better car to keep for many many years without the worries of the regular 996 engines and transmissions.
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07-22-2004, 11:16 AM
#8
Three Wheelin'
I think I have been clear enough. As I said I have "heard rumours"......thus I have no proof.
However my source of information is extremely good. Suffice to say that it was a Porsche employee who told me this information.
The GT3 uses a different engine block and although it too may suffer RMS problems it is not
to be confused with the RMS problem in the 996 C2/C4 which fails because of a design flaw.
However my source of information is extremely good. Suffice to say that it was a Porsche employee who told me this information.
The GT3 uses a different engine block and although it too may suffer RMS problems it is not
to be confused with the RMS problem in the 996 C2/C4 which fails because of a design flaw.
07-22-2004, 11:34 AM
#9
Three Wheelin'
Berny:
While your analysis of potential catastrophic engine failures due to an RMS or IS seal leak are all spot on, they are edge cases failures, and the reason they are failures is because of loss of oil pressure. Lots of things can create loss of oil pressure in an engine including catastrophic failure of an RMS of IS. Never the less, there has never been a single case of a customer having had an engine fail in the way you describe because of these seals, or engine case manufacturing issues. In addition, there has never been a single case of clutch, pressure plate or flywheel damage because of a failed RMS or IS seal.
I would also think that Porsche and everyone that has commented on this issue wants a solution to the issue and I'm sure that Porsche and its suppliers are working to do so.
I'm not trying to minimize the issue only to add balance to an issue that is being a little overblown in its implications of impacting the reliability of the engine.
While your analysis of potential catastrophic engine failures due to an RMS or IS seal leak are all spot on, they are edge cases failures, and the reason they are failures is because of loss of oil pressure. Lots of things can create loss of oil pressure in an engine including catastrophic failure of an RMS of IS. Never the less, there has never been a single case of a customer having had an engine fail in the way you describe because of these seals, or engine case manufacturing issues. In addition, there has never been a single case of clutch, pressure plate or flywheel damage because of a failed RMS or IS seal.
I would also think that Porsche and everyone that has commented on this issue wants a solution to the issue and I'm sure that Porsche and its suppliers are working to do so.
I'm not trying to minimize the issue only to add balance to an issue that is being a little overblown in its implications of impacting the reliability of the engine.
07-22-2004, 12:47 PM
#10
Three Wheelin'
Orient, in most cases in the US the engine is replaced without quibble and often even for out of warranty cases. In the RoW this is not the case. In any case, the engine is wisked off back to PAG to rebuild. None of us are ever the wiser to the cause or damage. Typically its a case of "We are going to replace your engine" and that's all you get. So there is no say if there has been a single customer having engine failure becuase of the RMS or not. We simply don't know.
However, there are a few clues:
* We are recently hearing of more than the usual number of engines blowing up. Why is this the case? We don't know because the engines are wisked away for rebuild.
* We are witnessing many more 996/986 engines are suffering RMS problems. The older the marque gets the more we see. Is it a coincidence that we are also seeing more and more engines blow up?
* If the RMS is such a small issue then why replace the engine....could it be to prevent catastrophic failure (and embarrasment) or that the engine block is too far gone to repair? In either case it's an expensive repair bill for out of warranty cars.
* If it's just a small oil leak then why not be told not to worry about it?
I must clarify that without doubt it would be extremely rare for an engine to blow up because of the RMS but it can and "probably" does happen. But this RMS problem is not trivial. It's expensive to repair, it is fairly (if not very) common, it reduces residual value of the vehicle, it may lead to further engine damage, and there is a good chance that the RMS will fail again once the first one is done. As to clutch damage. I have read of several clutches having to be replaced because of oil contamination from a failed Seal....RMS or IMS.
The main issue is that this car is a very expensive item and we would not buy it if we knew there was a good to fair chance that it has a latent defect. You say your not trying to minimise the issue. I say you are. As for it being a little overblow in its implications, I don't want to say any more (for legal reasons) but I have had a communication from Porsche explaining the problem in detail. It clearly states the problem and its implications. Please don't ask me for details because I do not want to go into it any further as it may jeopardise any legal position I may have. Suffice to say the RMS has very serious implications to the engine, gearbox and/or clutch.
I want to stress that I am not trying to inject doom and gloom into this subject. I love my Porsche just like everyone else here. This is my 3rd 911. But the fact is there is a serious problem with the drivetrain in these cars and while you guys in the US are somewhat protected, the RoW are not. The stance taken by PAG is unrealistic and unfair and it is beyond the law in many cases but they have not yet been brought to compensate for it yet. This is about to change
However, the RMS is fast becoming a most talked about issue in regards to this marque in both industry media and the Forums. More and more it is brought to light in resepct of "What is Porsche going to do about it". PCGB have even conducted a survey, the results not yet known. I will be attending a meeting on 31st with Porsche UK and arranged by PCGB to discuss the outcome. The balance is that we are all sitting on a loaded gun and none of us like it.
However, there are a few clues:
* We are recently hearing of more than the usual number of engines blowing up. Why is this the case? We don't know because the engines are wisked away for rebuild.
* We are witnessing many more 996/986 engines are suffering RMS problems. The older the marque gets the more we see. Is it a coincidence that we are also seeing more and more engines blow up?
* If the RMS is such a small issue then why replace the engine....could it be to prevent catastrophic failure (and embarrasment) or that the engine block is too far gone to repair? In either case it's an expensive repair bill for out of warranty cars.
* If it's just a small oil leak then why not be told not to worry about it?
I must clarify that without doubt it would be extremely rare for an engine to blow up because of the RMS but it can and "probably" does happen. But this RMS problem is not trivial. It's expensive to repair, it is fairly (if not very) common, it reduces residual value of the vehicle, it may lead to further engine damage, and there is a good chance that the RMS will fail again once the first one is done. As to clutch damage. I have read of several clutches having to be replaced because of oil contamination from a failed Seal....RMS or IMS.
The main issue is that this car is a very expensive item and we would not buy it if we knew there was a good to fair chance that it has a latent defect. You say your not trying to minimise the issue. I say you are. As for it being a little overblow in its implications, I don't want to say any more (for legal reasons) but I have had a communication from Porsche explaining the problem in detail. It clearly states the problem and its implications. Please don't ask me for details because I do not want to go into it any further as it may jeopardise any legal position I may have. Suffice to say the RMS has very serious implications to the engine, gearbox and/or clutch.
I want to stress that I am not trying to inject doom and gloom into this subject. I love my Porsche just like everyone else here. This is my 3rd 911. But the fact is there is a serious problem with the drivetrain in these cars and while you guys in the US are somewhat protected, the RoW are not. The stance taken by PAG is unrealistic and unfair and it is beyond the law in many cases but they have not yet been brought to compensate for it yet. This is about to change
However, the RMS is fast becoming a most talked about issue in regards to this marque in both industry media and the Forums. More and more it is brought to light in resepct of "What is Porsche going to do about it". PCGB have even conducted a survey, the results not yet known. I will be attending a meeting on 31st with Porsche UK and arranged by PCGB to discuss the outcome. The balance is that we are all sitting on a loaded gun and none of us like it.
07-22-2004, 12:59 PM
#11
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Scouser,
Given the insight you have gained into the issue, balanced by your enjoyment of the car, I would be very interested in your answer to the following question.
Would you recommend buying a 996?
and if so, with what caveats or conditions?
Regards,
Lomotpk
(In the process of selling my 930 to buy.... a 996, maybe?)
Given the insight you have gained into the issue, balanced by your enjoyment of the car, I would be very interested in your answer to the following question.
Would you recommend buying a 996?
and if so, with what caveats or conditions?
Regards,
Lomotpk
(In the process of selling my 930 to buy.... a 996, maybe?)
07-22-2004, 01:10 PM
#12
Three Wheelin'
Yes yes yes!!! This is the only car "there is no substitution". The driving pleasure cannot be put into words. The sheer music it plays is enough to raise the hair on your back. WIthout doubt I would recommend buying a 996.
The only condition is don't buy it without PORSCHE warranty and stay on the extended warranty scheme for as long as it is permitted. Ensure the warranty covers seal/engine replacements.
The only caveat is that they are not so cheap to maintain (general maintenance). But then this is a Porsche so this comes part and parcel of owning one. It is after all a luxury item.
So don't be put off buying one. Just choose wisely and get the warranty.
The only condition is don't buy it without PORSCHE warranty and stay on the extended warranty scheme for as long as it is permitted. Ensure the warranty covers seal/engine replacements.
The only caveat is that they are not so cheap to maintain (general maintenance). But then this is a Porsche so this comes part and parcel of owning one. It is after all a luxury item.
So don't be put off buying one. Just choose wisely and get the warranty.
07-22-2004, 03:33 PM
#13
Three Wheelin'
What is the standard warranty in the UK for the 996? Here in the US it is 4 years/50,000 miles.
On the subject of cost of ownership, I have found that routine maintenance on my 996 is no more involved than a Toyota Corolla, in fact it is easier than the Toyota. Change the oil, filter and pollen filter every 15K miles, Air filter at 30K miles and Plugs at 60K miles. What could be easier? My 15K services cost me $85 and an hour of my time. These cars are very cheap to maintain. If you are paying more than that, you should learn to change your own oil, and pay yourself what you are giving to a dealer. As far as quality, the car has been in the shop 4 times in the last 3 years for 3 items, Radio, airbag sensor, and RM & IM seal. That is a pretty good record. Even the RMS/IM seal changeout was done in under 2 hours.
On the subject of cost of ownership, I have found that routine maintenance on my 996 is no more involved than a Toyota Corolla, in fact it is easier than the Toyota. Change the oil, filter and pollen filter every 15K miles, Air filter at 30K miles and Plugs at 60K miles. What could be easier? My 15K services cost me $85 and an hour of my time. These cars are very cheap to maintain. If you are paying more than that, you should learn to change your own oil, and pay yourself what you are giving to a dealer. As far as quality, the car has been in the shop 4 times in the last 3 years for 3 items, Radio, airbag sensor, and RM & IM seal. That is a pretty good record. Even the RMS/IM seal changeout was done in under 2 hours.
07-22-2004, 04:55 PM
#14
Three Wheelin'
Warranty in the UK for any Porsche is 2 years.
These cars are not cheap to maintain. The minor service is about average. A major service can and usually does end up expensive but as I said this is all part and parcel of owning an expensive car.
I have no problems with the general wear and tear maintenance costs.
I find it impossible to believe that it took less than 2 housr to replace the IMS and RMS. Typically it is an 8 hour job at best. I have even heard of it taking 10 hours. The least I have heard is 6 hours. 2 hours is impossible.
These cars are not cheap to maintain. The minor service is about average. A major service can and usually does end up expensive but as I said this is all part and parcel of owning an expensive car.
I have no problems with the general wear and tear maintenance costs.
I find it impossible to believe that it took less than 2 housr to replace the IMS and RMS. Typically it is an 8 hour job at best. I have even heard of it taking 10 hours. The least I have heard is 6 hours. 2 hours is impossible.
07-22-2004, 05:23 PM
#15
Three Wheelin'
That is unfortunate that the UK warranty is not as good as here in the US. I guess we have better lawyers here.
As far as an R& R on these seals, 2 hours is a best time, it is normally closer to 3. Think about it.
1. Remove rear aero cover exposing transmission.
2. Disconnect shifter cables, electrical cables and half shafts
3. unbolt transmission from engine and sub chassis
4. Remove transmission
5. remove pressure plate and clutch plate
6. remove flywheel
7. pull out the old RMS, unbolt IMS cover and remove
8. Clean everything up, check the tolerances where the seals go.
9. Put in new seals
9. Put everything back, reverse of above.
Even I could do it in 4 hours. Bottom line, it is not a big deal. Most places here in the states will have you in at 7 am and out by noon, assuming the tech can focus on just this one job and not be interrupted.
In fact, I was looking at some photos that I took of the last time the RMS was changed out on my 996, and by looking at the time code on each photo, I found the time from unbolting the aero cover and disconnecting the halfshafts to having the RMS exposed was only 17 minutes.
As far as an R& R on these seals, 2 hours is a best time, it is normally closer to 3. Think about it.
1. Remove rear aero cover exposing transmission.
2. Disconnect shifter cables, electrical cables and half shafts
3. unbolt transmission from engine and sub chassis
4. Remove transmission
5. remove pressure plate and clutch plate
6. remove flywheel
7. pull out the old RMS, unbolt IMS cover and remove
8. Clean everything up, check the tolerances where the seals go.
9. Put in new seals
9. Put everything back, reverse of above.
Even I could do it in 4 hours. Bottom line, it is not a big deal. Most places here in the states will have you in at 7 am and out by noon, assuming the tech can focus on just this one job and not be interrupted.
In fact, I was looking at some photos that I took of the last time the RMS was changed out on my 996, and by looking at the time code on each photo, I found the time from unbolting the aero cover and disconnecting the halfshafts to having the RMS exposed was only 17 minutes.