low miles/IMS problems

[davea1954]

Looking at buying a 2002 Carrera with 12,000 miles on a 2007 replacement motor from Porsche installed under a CPO warranty. My biggest question/ concern - OK big concern, is that the 2000 miles per year average use of this vehicle since this new motor was installed may lead to a greater chance of an IMS failure. Any opinions on this concern? Thanks

[Silver_TT]

This thread should be moved to the 996 Series forum.

 

With regard to your question, some folks say that a car that wasn't driven as often will be more prone to IMS failure.  While these cars are best driven frequently for a number of reasons, the IMS question you raise will get you different answers when asking different people.  I'm not sure if you're planning on having the IMS done but one thing you might want to pay close attention to is the replacement motor to see which bearing is used.  If your motor was replaced in 2007 it may have Porsche's final solution with an IMS that can't be replaced without a tear down of the engine -- although some folks have reported success tearing the seal off the bearing so oil can freely get in there as an alternative.

 

Should be quite a few of the models you are looking at for very attractive prices.  So get one that looks like it's been well cared for, and maybe even price in the cost to replace the IMS if it's possible.  Good luck with the purchase.

[davea1954]

Thanks Silver for the reply. This might show my ignorance on the subject, but I figured even though the car is a 996 the motor being a Porsche rebuilt replacement from 2007 put's it (motor) in the 997 range - at least it made sense to me! According to info from another Porsche site any motor rebuilt after 2005 has the non-serviceable non replaceable IMS bearing. If this motor had the 2002 - 2005 IMS bearing I figured I could at least replace it with an LN bearing and have that peace of mind. Unfortunately, this doesn't appear possible, and removing the engine and cracking the block is not a reasonable solution!!! You're right about all the opinions, it's just too bad with a nearly $30,000 motor there can't be some consensus based on concrete evidence for this problem. What to do? Corvette is looking better all the time. Thanks again.   

[JFP in PA]

Thanks Silver for the reply. This might show my ignorance on the subject, but I figured even though the car is a 996 the motor being a Porsche rebuilt replacement from 2007 put's it (motor) in the 997 range - at least it made sense to me! According to info from another Porsche site any motor rebuilt after 2005 has the non-serviceable non replaceable IMS bearing. If this motor had the 2002 - 2005 IMS bearing I figured I could at least replace it with an LN bearing and have that peace of mind. Unfortunately, this doesn't appear possible, and removing the engine and cracking the block is not a reasonable solution!!! You're right about all the opinions, it's just too bad with a nearly $30,000 motor there can't be some consensus based on concrete evidence for this problem. What to do? Corvette is looking better all the time. Thanks again.   

 

The last design IMS, which it sounds like you have in this case, is reasonably sturdy, but not totally immune to failure.  General reports seem to indicate that this design is more prone to fail on a car that is heavily tracked than on the street, while earlier versions could fail at any time.  Silver_TT noted one approach that has seen considerable success, pulling the rear seal off the OEM bearing so it can get splash lubrication (which all LN bearings except the Solution use).  We have several customers running this way without any issues.

[davea1954]

Thanks JFP, yes pulling the seal is an option. I understand there are also aftermarket products that will pump oil to the area of the bearing. Do you think they are worth it?

Just talked to current owner and he said car was driven about twice a week, more in the summer less in the winter, mostly trips around town but an occasional trip or two out of town too. Oil was changed once a year. So, at least the car didn't sit in the garage for weeks/months on end. Does this info add anything to the issue of the IMS reliability for this motor? 

[JFP in PA]

Thanks JFP, yes pulling the seal is an option. I understand there are also aftermarket products that will pump oil to the area of the bearing. Do you think they are worth it?

Just talked to current owner and he said car was driven about twice a week, more in the summer less in the winter, mostly trips around town but an occasional trip or two out of town too. Oil was changed once a year. So, at least the car didn't sit in the garage for weeks/months on end. Does this info add anything to the issue of the IMS reliability for this motor? 

 

There are aftermarket forced oiling systems, but with the exception of the non ball bearing LN IMS Solution system (which is only for serviceable single row bearing engine's), I am not a big fan of them for a couple of reasons.  While the marketer's of these oiling systems like to say they spray "filtered, cool oil" into the bearing, in reality they source the oil feed from one of the hottest and dirtiest parts of the engine to feed the bearing.  Secondly, as you cannot remove your bearing and put a plug behind it in the shaft housing, you are relying on the OEM inner bearing seal to keep the oil from flooding the shaft, and the reason all the OEM IMS bearings have problems in the first place is that the seals start to leak and wash the grease out of the bearing, so the rear seal is going to leak oil into the shaft, which is not good.  Third, there has been considerable debate about getting "too much" oil into the bearing, which can also cause problems.

 

LN engineering and Jake Raby did their homework on the their replacement ceramic hybrid bearings, and stayed away from forced oil feeds (even though they own the rights to one of the slickest forced oil feed designs), preferring to use an open rear bearing design that is splash lubricated by the engine rotation.  And with nearly 18,000 of them installed this way, it seems to be working just fine.

 

While there has been considerable debate about "garage queens" suffering more problems than daily drivers, I'm not completely convinced that is a major contributing factor in premature IMS failures.

[Silver_TT]

Before you jump off the deep end and buy a Corvette, why not consider a 996 with a serviceable bearing?  There's no shortage of 2002's with the original motor out there if you like that year.  Get one that's been taken care of and price in a LN IMS replacement.  Otherwise, if you can splurge, spend $40K and get a 996 Turbo and never think about an "IMS" again.

[davea1954]

Thanks for all the replies. There is a turbo in my area for $39K, but with 60k miles. Maybe yes, maybe no about good tradeoff with 2002 Carrera4 with 32K, and 12K on 2007 rebuilt engine. 400+ HP is sure appealing! Straight away competition with 400 - 436 HP 2007 - 2008 Corvette and Porsche handling! Of course the $10K extra may be a deal breaker - wife to consider. Thanks again for all the replies.

[Silver_TT]

Definitely hear you on the wife front, that is a very important consideration. A TT with 60K miles is actually still very low mileage in my opinion though if the car was well taken care of and maintained. $39K is a reasonable price if there's nothing wrong with it. 33% more cost than the car you are looking at (the difference if which is only 25% the coat of the TT) with a rebuilt engine, but no M96 headaches and a much more reliable and powerful engine. Turbo owners are risk averse and sleep better at night, but they pay more to do so.

Edited August 3, 2014 by Silver_TT

[san rensho]

The last gen of the IMSB, which I assume you have since the motor was replaced in 2007, has a failure rate of less than 1% according to the data provided by Porsche pursuant to tha class action suit filed against them. Just drive it like you stole it.