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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHIMS Flange replaced but not the bearing?
Reported or suspected cause
ims end plate
Reported cause
No successful repair reported for this finding.
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Reported cause
The SM told me that because the RMS and IMS were so close together that often times (earlier RMS repairs) when just the RMS was replaced the car was back with an RMS leak when the real problem was the IMS end plate.
Leading evidence: 'ims end plate' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'ims end plate' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check leaks, a ppi will not guarantee' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
Doubtful that the bearing was pulled and checked when the flange was replaced.
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Performed · outcome unconfirmed
My dealer recommended the IMSB be replaced and provided me a quote to do so but I opted for the Solution installed by a certified shop.
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Performed · outcome unconfirmed
The IMSB is a sealed bearing, and it's not designed to be lubricated by an external source.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Performed · outcome unconfirmed
The SM told me that because the RMS and IMS were so close together that often times (earlier RMS repairs) when just the RMS was replaced the car was back with an RMS leak when the real problem was the IMS end plate.
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Suggestion
The only check that was made at the time the RMS/IMS end plate were replaced was to check the location of the crankshaft journal to ensure the crank was not out of position.
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The SM told me that because the RMS and IMS were so close together that often times (earlier RMS repairs) when just the RMS was replaced the car was back with an RMS leak when the real problem was the IMS end plate.
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ims end plate
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
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Reported cause
The SM told me that because the RMS and IMS were so close together that often times (earlier RMS repairs) when just the RMS was replaced the car was back with an RMS leak when the real problem was the IMS end plate.
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So I'm new to the community, have been researching here, and now close to pulling the trigger on an '02 C2.
I've pulled the maintenance records from the dealer, where even tires were replaced/serviced by the owner. While I had the service advisor on the phone, I asked more pointed questions of the data dump that he sent me.
The RMS was replaced in '06-- what is the typical service life of these? The PPI will of course reveal its integrity now, but I wanted to see if there was a rule of thumb (other than if it ain't broke don't fix it).
So here's the peculiar part: in the same RMS service above, the dealer replaced the IMS Flange (according to the service notes), but not the IMS bearing itself. Does that strike you all as a bit odd? Or was the IMS bearing issue not yet known and infamous in '06? Was the design of the flange in the '02 MY flawed somehow? Why would the dealer skip the bearing-- the labor is done and the part inexpensive. I can only assume the bearing was pulled and determined to be sound enough to reinstall the existing one.
Thanks for your advice, and I hope to be a 996 owner soon.
Hello and welcome. The RMS was notorious for leaking and Porsche had more than a few updated designs so yes, it's replacement in 06 would be typical. The IMSB failure was not so well known, but the IMS seal was known to weap or leak and again there were a redesigns of the seal and flange so in 06 replacing the bearing at the same time would not be typical at all.
Doubtful that the bearing was pulled and checked when the flange was replaced. And, other than a visual external check for leaks, a PPI will not guarantee that the RMS is not weaping or leaking. I have an 04 C2 and the RMS was replaced by the dealer before I purchased the car in 2007. In Sept of 2012 I had the clutch and IMSB replaced and the RMS was still bone dry - 5 years and over 50k miles of service with no issue.
Porsche developed a revised flange to address leaks. It has better seals than the original flange. I have one in my car that I installed in 2009. At that time LN Engineering and Flat6 were still developing the techniques for removing the IMS bearings. They had a pretty good handle on the single row bearing removal, but not the dual row bearing that my car has. That is why I did not do the bearing upgrade back then. I did remove the outer seal on my bearing then.
There is no way dealers were replacing bearings back in 06. Dealers were late in adopting bearing replacement even after the removal techniques were developed.
Not odd based on my experience with my 02 Boxster. Back in 02 the engine exhibited the symptoms of an RMS leak.
The car was under warranty so in it went.
The SM told me that because the RMS and IMS were so close together that often times (earlier RMS repairs) when just the RMS was replaced the car was back with an RMS leak when the real problem was the IMS end plate.
So the SOP was to at the same time the RMS was replaced to replace the IMS flange or end plate.
The new one had an updated/improved 3-rib seal vs. the single o-ring seal of the old one. Additionally the 3 bolts were micro-sealed to prevent oil from seeping past the bolt threads and out from around the bolt head.
The only check that was made at the time the RMS/IMS end plate were replaced was to check the location of the crankshaft journal to ensure the crank was not out of position. In a few cases this was found to be the case and the engine was replaced. The RMS would not remain oil tight for long and often times the engine would self destruct before the RMS leaked enough to make a problem known.
This was way before the IMSB was even an issue.
In the case of the car you are asking about, even though in 06 IMSB failures were not unheard of, I can assure you the IMSB bearing was not thoroughly inspected and found ok.
I'm sure it was superficially inspected. Well, that may not be the best word, but I'm sure had there been obvious signs of bearing imminent bearing failure just the IMS end plate was replaced.
The bearing would not have been replaced in any event. The engine would have been replaced.
Wow, thanks for the great advice and historical perspective everyone. Gives me a bit of confidence that they did all that was known at that time.
The owner has put on about 17k miles since then, and disclosed that the RMS showed a drop of leakage while storing over the winter. I'd assume that to be normal in a car that is 11 years old, and quite good-- I've had a Range Rover classic and Triumph, so a leak like that would have been suspect in those cars.
Now at the risk of being a total noob... how is the RMS/IMS kept lubed? As part of the normal engine oil system? Or some other way like a transmission or power steering box? Sorry, I don't have the manuals yet to read more on the subject.
Thanks in advance!
The RMS is lubed by oil splash/oil vapor that is present in the crankcase. The RMS doesn't need much lubrication and in fact doesn't want to be subject to much oil because the more oil it has to keep in the engine.
At one end the IMS (intermediate shaft) is lubed via high pressure oil from the oil pump. At the other end the IMS is supported by a sealed ball/roller bearing. This bearing is nominally lubed by the entrapped grease/bearing lube sealed in the bearing.
There is a question as to whether the bearing seal can survive intact over the miles/years. Almost certainly if the seal fails whatever oil gets to the baring will wash out the grease. The bearing is kind of off the beaten path when it comes to oiling, in that there is no oil feed to this area. Since the bearing is sealed there is no need.
From them on the thinking is the bearing is lubed by any oil that manages to make its way to the bearing.
The seal on the IMS flange/end plate doesn't rotate nor does anything rotate around it so it doesn't need lubrication. The fact it is subjected to considerable oil keeps it wet and pliable and in no danger from drying out and thus shrinking.
You've actually hit on the flaw with the IMSB design. The IMSB is a sealed bearing, and it's not designed to be lubricated by an external source. After it has been used for a while, it tends to lose the seal, allowing the original lubricant to leak out and engine oil seep into the bearing.
You often hear that cars that are driven frequently are less prone to IMSB failure than low-mileage cars. The theory behind this is that cars that are driven frequently keep the IMSB sufficiently lubricated that it will continue to function effectively. If a car isn't driven frequently, the engine oil that has penetrated the seal will seep out, leaving a "dry" bearing. This can be especially problematic at start up, causing rapid failure of the bearing. This theory makes sense, but make no mistake - cars that are driven regularly can still suffer IMSB failure.
Your best bet is to treat the IMSB as a wear item and replace it every so often. Upgrading to a ceramic bearing like the one from LN Engineering is also a good idea.
This isn't meant to scare you away - just to inform you. I'm still on my original IMSB at ~123K miles. I'm planning to change it to a ceramic bearing on my next clutch change, which won't be long.
@macster, that's some amazing mileage on your boxster or any car for that matter. Well done.
Thanks to the folks on this thread. Great stuff to know about how it all works. Per the PPI, the current RMS is showing a long slow leak, so a replacement is in order.
They cleaned it up down there, and ran it on the lift so they could watch it, and it stayed dry. I confirmed with the tech that the newer RMS is improved and more substantial.
There are some other nitpicky things, but the car has been taken care of. Thanks again, and I'll post pictures if I make it so.
Reviving an old thread to get forum expertise.
I recently made an impulse purchase of a low mileage 2003 C2 coupe from a BMW dealer. Before I purchased, the BMW dealer confirmed with the Porsche dealer that the IMS retrofit had been completed in 2015. And I called the Porsche dealer myself and confirmed the same. Then I bought the car.
A week later, I stop by the Porsche dealer to get a copy of the service order for the IMS/RMS for my records. Upon review, I only see that the IMS flange was replaced...there is no mention of the IMS bearing being replaced. Additionally, the cost of parts on the invoice is only $263 with labor being $1485. I know the LNE solution costs over $650 so the low cost of the parts raises additional concerns.
If the Porsche dealer only replaced the IMS flange and did not replace the IMS bearing, does that reduce the risk of IMS failure? Or is the likelihood for failure the same since the potentially faulty IMS bearing was not replaced?
Thanks for your help.
If they removed the outer seal on the original (1 or 2 row???) bearing, that would be good.Any mention of that ? From the part # of the replacement flange on the Invoice , you may learn which bearing you have ?From your MY of 2003 it is probably a single. Others may have better suggestions.
Here is the section of the invoice that shows the parts used. There is a part number for a "SEAL RING 27 x 3" but I'm not sure if that means anything. Why would it be good if they removed the outer seal? Thanks again for your input.
IMSparts_zps6nxjcpnq.jpg
Removing the outer seal of the IMSB allows oil to splash in and lubricate the bearing.
Many believe that if you don't change the bearing then removing the seal on the existing one improves longevity.
Porsche dealers will install and even recommend...they just won't provide any warranty. In fact most dealers will install anything you ask them to. My dealer recommended the IMSB be replaced and provided me a quote to do so but I opted for the Solution installed by a certified shop.
,,,because the grease in the original bearing leaks out when(not if) the seals fail. So it makes sense to provide an oil bath for the bearing by removing the outer seal.This is exactly what most new IMSB kits do and have done for years. It is not so much belief as proven field results from thousands of IMSB retrofitted cars.Obviously an upgraded ,new IMS bearing is a way more intelligent alternative but in this case, the OP got neither it seems.YEMV
I said "believe" to avoid the sh!tstorm that ensues when anyone states anything as the absolute truth on the 996 forum.
I believe that removing the seal is a good thing. However, others may not so I am covering my bases
Agree with what others have said. I have service records that state almost the exact same as yours. Car was in to fix an RMS leak and I think it was SOP to replace the IMS flange/seal at the same time to update that seal and reduce the odds that the car comes back in again complaining of a new RMS leak.
Which means they will only install a Porsche part. In this case, the larger 997.1 single row bearing that requires the case to be split.
I will be stopping at my local Porsche dealership tomorrow to get an oil filter. I will ask the service department if they will install an LN Engineering bearing or the IMS Solution, which requires notching the case for the oil line.
A dealership is not the best place to have this work done. Remember, dealers said that replacing the IMS Bearing was impossible. Dealers seldom register their installs, seldom follow our directives, and often have installation complications that others do not.
These cars are too old to go to the dealer, anyway.
I went to the Porsche dealer in Greenville SC today to pickup an oil filter ($32!), so I can do a rush oil change this weekend. I spoke to one of the service managers while I was there. He stated that they would be willing to install an aftermarket bearing that he sourced, since there was no Porsche alternative. To him, cracking the case to install the larger M97 single row bearing was not a realistic alternative. I asked about the IMS Solution and some of the other bearings that require the engine case to be notched to install an oil line and he said absolutely not. They would not make any modifications to the case.
I figured there was probably a cheaper alternative out there, and I know you can buy the OE filters for about $14 on line with the crush washer. I wanted to do a little experiment regarding how much they charge. I walked into the parts department, told them I needed a filter and pulled out my credit card. $32 was the result.
If it were up to me, not a single IMS Solution would have been installed at any dealership. There are not any dealers who are Certified IMS Solution Installers, and never will be.
After all, those are the same people that said it was impossible to remove any IMS Bearing, from any M96 engine. Remember?
I go out of my way to avoid the Porsche Dealer.
The people who will help these cars survive are Indies and developers like Jake.And Forums like this.
What has Porsche done lately to give Technical support your M96 ?
They don't even allow public access to engine rebuild measurements .That tells you what Porsche thinks of you and your old P-car.
They have their place, I really like the dealership.
Maybe its different here, there are only 3 in Victoria here so they are fairly good. Parts dept are quite useful, we don't have the online retailers like you have access to (not without ridiculous shipping prices!)
Just replaced my IMSB on my '03 C4S Tip with 91k - original single row. Oil seals were still intact. Bearing looked good. Replaced with EPS at my indie's suggestion (Redstone Performance Engineering). Saw that and held that part before going in. Compared to the factory unit, incredibly more stout. Very confident in the choice and the work.
