IMSB fear

I am looking at a '02 C4S w/ 50K+ miles on it but I am hesitating because of the IMSB issue. Is this realistic? Car is not leaking any oil. It has been well maintained by the current owner but he only has the service history that he did. He is not aware of any work having been done on the RMS or the IMSB. Is there a threshold mileage that once you get past that, you can be fairly sure the engine is safe? Thanks for any input.

Quotes source post: 10675362

I have read different theories about the danger spread, and what I have heard most often is 40K to 80K; however, this is a subjective number. Just maintain your car with fluids and any other regular maintenance issues and you should be ok. The real number of IMS failures are a very small percentage of 996s.

GAAAAHHHHH!!! Yet another new IMSB thread!!!! I'M BLIND!!!!!!

If it is causing you concern you have four choices: 1. Install the ims monitoring solution (no idea if it works) 2. Get the work done. 3. Budget to have the work done. 4. Don't buy a 996 or early 997.

Quotes source post: 10675449

You guys crack me up IMS threads will continue to surface as long as new people buy these cars. The IMS issue is usually the first thing someone will bring up when I tell them I drive or own a 996

There will always be a chance that the IMSB will fail. The probability is low, but if it does fail the cost will be high. Fortunately for you there are a couple of upgrades available which virtually eliminate the chance that the IMSB will fail. The cost is about $1000 if you wait until you have to replace the clutch anyway, or about $2500 (estimate) if you choose to go in just for the IMSB upgrade...although you'd be crazy not to replace the clutch while you are in there. Be aware that the IMSB is not the only failure mode for the M96 engine. Search the user billyboy here and you will see how his engine broke a timing chain. That said - any high performance engine is vulnerable to failure regardless of manufacturer... and who knows how billyboy's engine was treated before he owned it. If any of this scares you - or if the costs described above seem high - then Porsche ownership may not be for you. Personally - I treat my car to a lot of maintenance and run it hard. In return, it has treated me like gold since I have owned it and I sleep like a baby. If it breaks I'll fix it...or not. Whatever.

Thanks for replies. Hopefully Cuda911's vision comes back soon. I really want to have a reliable DD so I may have to go to the air cooled cars. Need the AWD for winter that leaves the 993s. Jasper's perspective was helpful. Kind of like if you have to ask how much something costs then you probably can't afford it. Thanks again.

I changed my IMSB at 101,500 miles. It did not appear to be failing (go to Albums... Jim's 04 996 IMS Solution for pictures). Additionally, you can see the cost. Do I sleep better having potentially averted a $20K rebuild? Yes, because I can afford the IMSolution.

Quotes source post: 10675546

My understanding (from the research I did before buying mine, your research may differ) is that the aircooled cars are A) more maintenance-intensive than the watercooled cars B) More expensive to maintain and C) More difficult to work on yourself. If the IMSB concerns you that much, replace it and don't worry about it for at least another 50k miles. Going to an aircooled 911 will probably not save you any money in maintenance costs even if you factor in the IMSB replacement. Asking how much something costs merely makes you a smart owner. Eliciting multiple opinions makes you even smarter. I thought I wanted a 964 (which also comes in AWD btw.). After researching I realized the 996 would be a better bet from a maintenance and daily driver perspective (FOR ME), but not for a long-term appreciation standpoint. Since I drive my car almost every day in all weather conditions I am enjoying my "investment" more than I would if I were waiting for the value of it to go up and not driving it as much.

WalterRohrI, I too liked the 964 until a indie near me advised me to stay away due to the maintenance issues. That was due more to the new tech that was in the 964. I did not realize the general maintenance on the air cooled cars was that much more - why is that? You point about just buying eyes wide open and factoring in the cost was already a line of thought going around my head. Thanks again

Vision is slowly returning.... I did the same at 101,200 miles. Funny, within a few hundred miles of what GTOWN83 did. However, I chose the LNS ceramic bearing rather than the IMS Solution. My original bearing looked just fine when it was taken out. But, I am in the same camp as GTOWN83, I sleep better having had that IMSB "upgrade" done. Thanks a hell of a lot. Now I'm lying awake at night again!!!

Well, you've come to the right place. Now start reading the 1,000+ threads! Be prepared for lots of fear mongering and nonsense mixed in with facts and real world IMSB upgrades.

At this point in the game, the IMS bearing should not be an impediment to purchasing a 996 if what you want is a 996. The process for replacing the bearing is now performed by plenty of shops. Replace the bearing every clutch or two or do the "solution" if you have a single-row bearing and do not want to treat the IMSB as a wear item. This should be filed away under "known issues" with AOS, water pump, and the other stuff we know needs to be treated as preventive maintenance.

5CHN3LL - Exactly right! I think of the IMS bearing replacement the same way I thought about the timing belt/water pump replacement in my 944S2 and 968 - it is just something you do to avoid a toasted engine. 944/968 owners have been spending $1,500 - 2,500 every 45K miles to avoid a damaged engine for decades. The IMS is really no different, and you don't have to do it over and over. Everybody just stop all the crying and handwringing. Consider the IMS a maintenance requirement, do it, and then drive the car. If you can't do that, you need to buy a Camry, not a Porsche.

If you are that worried now, please don't buy a 996. Ulcers suck.

After 2 brief months with the 996, I would get another in a heartbeat. They are fairly easy to work on and with forums like this and renn tech almost all DIY's are there for whatever your comfort level. Also, it seems like all the major problems have been ID'd and have solutions. It is just a matter of picking the right car and then doing what needs to be done. IMS is easy. If not done, do it. If done, don't worry.

Good solid answers here. So far, I've done all the work on my car and have saved thousands, but you have to remember these cars are OLD, jeez, and old cars need maintenance, and Porsche maintenance, if you don't DIY is expensive. Air cooled, more so, by far, just ask any Porsche indie mechanic. I actually do prefer the look of the 993 over the 996 as a more classic Porsche look, and a more involved driving experience, and a ton of fun, but as a DD? You're kidding right? I'm guessing you may have not driven them back to back. I was of the same thought when I was looking for mine in late 2007 (though not as a DD) and drove a few 993s, shocked at the prices for the mileage, but man, what a ride. I knew about the IMSB issues then, before there was any common solution, besides having it redone, so I also was avoiding the M96 engine cars, but then I drove one, and I thought, DAMN, no going back now. There is NO comparison, once you do, the 996 just blows away the 993 in every category, except the IMSB! I have a friend that bought a '96 993 Cab, always wanted a REAL Porsche, not a bloated, water cooled wanna be, as he jokingly called them, very nice shape, great looker, same thought process as mine, and he had never driven a 996. Actually, turned down offers to drive mine, when he was looking for his 993. He does some DIY, not as much as me, but he has spent more in the first year of owning it than I have spent, in 5 years of owning mine, (not counting the PSS9s I put in, and PS2 tires), and most of mine was preventative. About a month ago, we were at the same place (a Porsche breakfast) with our cars, and he finally agreed to swap and do a short drive. When we got back he just kept shaking his head and saying "Damn", over and over. He's still keeping his car, as he truly loves the look, but his opinion of the 996 has totally changed. That said, just last week, two friends on mine, not local to me, both bought Boxsters a few months ago, one a 2004 with 35k miles on it, from a Porsche dealer, and the other a 2002 with 55k, from the owner, but it had the L&N CH IMSB installed by the dealership (Cary, NC), 6 months & 3000 miles ago. The guy that bought the 2004 never heard of the IMSB, but the other did, so was looking for a retro fitted car. 2 days apart, both while just starting their cars last week, had their IMSBs fail and trash the engines!!! The 2004 really screwed his up as he kept trying to get the engine running, despite the noise and clatter. Seriously! The 2002, admits he noticed a small amount of oil collecting under the car for about 2 weeks prior, but wasn't worried it was serious as he knew the IMSB was new. Both have been quoted a crate replacement in the $22k range, or a used engine in the $14k range!! The dealership, so far, is not owning up to any defect or poor install (my bet) of the IMSB, nor are they willing to cut him a break on any install. He's already in to them for over a grand on the diagnostics, tranny pull, etc, which seems pretty excessive to me. They keep telling him the bearing actually broke!?!? I'm leaning more now towards the Solution, for my car, when I get the clutch & RMS done. Hopefully, my Porsche indie, a well known and respected one, will have been approved by Jake to do them when I get them done. I'm not too worried at the moment at all, as I do have the IMSG installed when they were relatively cheap during the initial group buy. So yeah, it happens, maybe not to you, but when it does, it sucks big time, so factor it in if it bothers you.

I agree that this thread has some good information for a prospective buyer. When I bought my C4S, I did lots of research here and talked to my independent Porsche mechanic first. I was aware of the IMSB issue, and I still chose a 996. My mechanic told me that they have seen far more failures of the IMSB on Boxsters than on 996s. Additionally, he told me that he has seen far more failures on MK I cars (double-row bearing) than on MK II cars. That being said, he said the numbers he has seen are low. I believe that a car that is well maintained and regularly driven is less likely to have issues. That was the case for my car. I never worry about driving the car hard. I did have my IMSB replaced with the LN Engineering ceramic bearing at ~125K miles when my clutch was changed. There were no signs of impending failure in my original bearing. I'm still enjoying the car very much, and I still love to run the engine up to redline. These are great driver's cars and they are an incredible value in the performance car world.