I love my low mileage, ( 65k) original engine, 3/98 production 99 C2 and like hearing about the longevity factor on the dual row bearing. Due to the fact that I have limited service history, it seems that the logical approach would be to replace the IMS bearing. So, while these posts may seem like beating a dead horse, guys like me can use them as a word to the wise and don't fudge on having a fresh bearing in their engines. Thanks for posting and keep it coming

 

My 2001 has 86,000 miles on the original bearing. The cover and seal were replaced at around 50k miles with a new clutch by the previous owner, but the bearing itself was not replaced. To me it doesn't make financial sense to replace it. ~$3-4000 repair on a ~$18,000 car to prevent a failure that has maybe a 10% likelihood. I've owned the car for over 3 years and gotten tremendous enjoyment out of it on an $18,000 purchase price. If it blows up, it makes the most sense to sell it as a roller or part it out and buy something else. Would still be a very good investment on a fun-per-dollar basis.

 

Something a friend who is a software security guys says comes to mind: risk equals probability times impact. The risk of a high impact, low probability event could exceed the risk of a high probability, low impact event. So with the expensive engine repair or replacement costs from a failed IMSB, it's pretty high (and quantifiable) impact. Even at low probability, it is a risky proposition. In that case, it all boils down to your risk tolerance.

 

This all makes sense. My feeling is that if you can't afford to throw away "teens" of thousands of dollars, you shouldn't drive a car that cost $70-100k when it was new. It's just not going to be enjoyable if you can't live in that reality that some percentage of the value of the car might just get eaten up. The beauty of these cars is that the market hates them, so you can buy a "supercar" for economy car price, but in the end it's still a relatively low-volume, needy car that could explode at any time, so if you can't afford to think of it as disposable, you won't enjoy owning it. But I don't see a reason to proactively spend the money up front to fix a phantom problem that may never occur; instead, I choose to just enjoy driving the car for free and roll the dice, and I'll take the financial hit later if it happens to come.

 

$3-$K repair? How'd you come up with that?

 

Thank you for your kind words. I agree with your personal view on the 996.

At first glance when the 996 came out, it was breathtaking !! A courageous new design with clear DNA of racing history. A completely new platform that was longer, wider, lighter, more powerful, better handling, more aero dynamic than previous designs. A true testimate to Porsche engineering.

Even with certain engine flaws revealed, the fact that some of the highest quality materials are used can lend its self to longevity and many many miles of service with little wear. Like you say, if you understand these flaws, calculate the risk, prepare for the worst, but hope for the best, the 996 will deliver.
If you are prepared for the worst, and it happens, then you are not devastated,and can't wait to get the car back on the road to enjoy. If you are not prepared, haven't correctly calculated the risk, or don't understand these flaws, you can be devastated when things don't go as you hoped !! Porsche made a true effort to build a great engine, using the best materials and processes the engineering department could source. I blame the accounting department for some of the shortcomings of this engine, namely the decision to use the same pistons for both banks instead of dedicated banks with appropriate offsets. also the decision to go to a single row 6204 IMSB instead of staying with the dual row, and others. But Porsche was in financial trouble and the 986 and 996 saved them...they were the best selling models for Porsche ever , until the Cayenne..

 

Lots of people on this site and others talking about what they spend on the repair. Am I wrong?

 

Me too. I don't lose any sleep over it, or a moment worrying about it. Just sharing a point of view.

 

That is not a repair. That is a remediation. In other words, proactively replacing the IMS bearing plus clutch, RMS, AOS, maybe flywheel. That is $5k. If the IMS bearing let's go, it is not $5k. It is more like $20k.

It is all about risk tolerance. As I tell my financial planner, if I make $50k on investments this year, it will make absolutely no difference to my life. If I lose $1k, I will be really pissed off. Very conservative approach. Probably wrong from an investment strategy but then, making money is not my life's priority. I chose a 996 for 2 main reasons: 1. Hated the 997.1 interior. That dated NAV plus silver paint all over the interior is just awful. Has the same IMS issues too. 2. I couldn't get over the 997 not having a spare tire. Yes, I could have purchased one, plus a jack etc. etc. As much criticism as there is about the 996 interior, I quite like it. It is all black, nothing fancy just functional. That sums me up. I like having a spare tire. Where am I going to find a 285/30/18 on a Saturday night driving 100 miles to my cottage? With the spare tire, I will likely make it there!

 

^ Truth.

 

replaced mine at 90K miles, 2001 C2......double row bearing came out and was in perfect condition....preventive maintenance with clutch replacement

 

My engine was replaced by the previous owner in 2006.
Replacement engine is M960IAT66X66900
I feel like I've seen a chart where the bearing type and engine number are charted.
The previous owner told me that in 2006, the shop that did the replacement was asked not to open the engine up, just send it back.
The receipt shows $18,987 as the total for parts and labor. In my stack of receipts I see the same shop provided an oil change just a week before.

 

I think a lot has to do with the year of the 996 and how it is driven. My 2007 had a Dchunk issue and the engine was rebuilt along with a new (latest from Porsche) IMS bearing. I now have 56K miles on it and
the engine blew for the second time during a DE event due to the IMS bearing failing. Early 996's have the large dual row IMS bearing, but from 2001 to 2005, Porsche used the small single row IMS bearing which
is the most prone of all IMS bearings to fail. 2006-2008 Porsche used a large diameter IMS bearing. 2009 on there is no IMS bearing in 911's .

 

 

129k on original bearing