Always wanted 1

As many of you probably do not know I recently joined the club with a 2000 C2. As near as I can tell, the car has not had the IMS taken care of. Before purchasing the car I did a bit of homework and ball parked what it might cost to have the bearing done should I purchase a car in need. I called LN Engineering and as it turns out, their shop is a half hour away. While I don't question the bearing itself as an answer to the problem, a few of the things they said on the phone and delivered in a quote (that they volunteered to send) made me a bit uneasy. I was wondering if anyone here has dealt directly with the shop, and if so, how was your experience? Here are some of the things that made me uneasy-

They want to prequalify the car before doing the bearing. I sort of get this, but the car has 19k miles and you can eat off the entire car, inside and out. No leaks, no noises, no consumption, etc. Should the car not pass the test, they can't do the bearing? From all that I've read this is a pass/fail kind of thing. The bearing has either sh#t itself or not.

They were very very eager to give me a "worst case scenario" quote, which frankly totaled the price of a really nice new used motor at almost $9000. It had a laundry list of items on it, from plugs and coils, to water pump, AOS, coolant, clutch, flywheel, brake fluid flush and on and on. I understand that this is a sort of pre-qualification of my pocketbook but it was followed by the statement of "we can't let the car leave our shop unless the job is done right". That makes me just a bit nervous. I'm very comfortable doing nearly everything on the list, yet I don't mind paying someone else to do some of it. It's things like "variocam wear pads" were I start to lose my competency. Frankly, the car has less than 20,000 miles, I'd expect none of these things to be a problem, especially with the condition of the car.

Why can't this stuff be easy? Just put in the damn bearing and don't touch anything else. I'm looking for some advice or suggestions here.

Turbojamie

I'd leave the damned thing alone and drive it.

Always wanted 1

I'd love to, but depending on who you listen to these are either the greatest engines in the world or Porsche ran out of aluminum, iron, and steel when making these things and used defective rock candy to cast parts.

Splitting Atoms

I haven't replaced my IMS Bearing yet. I will in the next few months. It makes sense to replace several of the items on the list since there is little additional labor, just the cost of parts, when the engine is out. The plastic bits, such as the water pump impeller, get brittle after 17 years.

As far as the pre-qualification, one of the things they will look for is evidence of any metal in the oil/filter/sump or on the IMS Bearing itself. If they replace a bearing with metal floating around the engine, the engine will fail at some point and they don't want to be held liable for giving you back an engine they know will fail.

sammaw

In answer to your question they seem to have a good rep on the forums etc. Believe they are active in this forum. The quote sounds fairly standard to what you might as well change while doing it. As you either remove the gearbox and/or drop the engine to replace the IMS, you might as well replace the clutch, rms, water pump, plugs and coils as they are easy to access and the additional labour isn't a lot compared doing them individually with the motor in the car. And if the engine is out, might as well do the wear pads on vario cam. I personally would change the IMSB, it made me sleep much better at night. But ultimately I waited until the clutch needed to be done. Low mileage garage queens the theory goes are more prone to IMSB failure. I have no proof either way.

Always wanted 1

In my experience with other cars, and I know this isn't other cars, once chunks of metal get in the motor, it is instantly or pretty quickly toast. Once those chunks of metal get through the bearings, if they don't cause a failure, something like oil pressure will suffer immediately. They take it a bit further with cam variations, what does that do?

Splitting Atoms

I'm talking about very small bits of metal. The bearings don't fail instantaneously. I have torn down non-Porsche engines that had very small bits of metal in the sump and the engine probably ran that way for hundreds, it not thousands, of miles. These tiny bits can lead to bore scoring if they get stuck in the piston rings, they can bind the oil pressure piston, score the crank shaft if they end up in the main or rod bearings, damage cam lobes and lifter/tappet surfaces, damage the oil pumps, etc. It can take a while before lower oil pressure or other symptoms become evident.

cringely

If you have it done, I'd contact Jake Raby at LN and ask him for a recommended place to have it done. I had the place I bought my (80,000 miles) 996 do the bearing replacement. Two years and 20,000 miles later, the engine grenades. By then, the 'dealer' was out of business and I had a rolling chassis worth $20,000 less than I had paid for the car.
Look at the https://rennlist.com/forums/996-foru...wn-engine.html thread and the subsequent 900+ posts to see how to properly rebuild a 996 after IMS failure. Ahsai has set the standard in how to do a do-it-yourself rebuild. He (and the other contributors) might be able to steer you to a competent shop (and save you the $20,000 I lost).
Best of luck.

dan_189

This sounds like a tricky situation, either way IMO you should replace it.

Also don't be fooled into a false sense of security whilst your kms (or I should say miles) are super low age should still be taken into consideration as all your components have or will have turned 17 at some point this year.

Flat6 Innovations

I'm not "at LN". Never have been.

That said, don't be fooled by a low mileage car. These engines must be more scrutinized than any other, as low mileage leads to fewer services, and these engines hat to sit around static.

The procedure that LN, or any Certified Installer will use to "pre- qualify" an engine for IMS Retrofit is mine. I developed it alongside the IMSR products. To dat that procedure has lead to a perfect success rate here, after 700 retrofit procedures have been carried out, including the very first one in history.

The car, and engine can be spotless, and the engine still not pass the pre- qualification. It happens here all the time. I've disqualified an engine with 4,000 miles on it, that car still had the original tires fitted.

To me low mileage, means high risk, and all engines are guilty until proven innocent by invasive evaluation. Time in service trumps mileage, and that comes from first hand experience.

That mindset will get you nowhere fast.... Well, except on the side of the road with a failed replacement bearing due to negligence, on the part of the installer. LN and my company co- invented these processes, we hold ourselves and our Certified Installers to a high standard, and we will not compromise. We will not simply do what an owner wants, and retrofit an engine without ensuring the rest of that engine is healthy enough to have the time and money spent on it. No corners will be cut, and no compromises will be accepted.

Yes, the variable valve timing wear pads can be well out of the wear spec in just 20,000 miles. Last week I had an 11,000 mile engine come in with a 9 degree cam deviation due to these wear pads. The Porsche spec for cam deviation is 6 degrees, that engine wasn't retrofitted, and I sent a several thousand dollar job down the road. Thats better than executing poor judgment, performing the retrofit, and the engine having complications later, or killing the replacement bearing.

You will find some hack shops that won;t pre- qualify anything. They will throw a bearing at an engine that has metal debris floating around in the oil thats visible, because they don't even look at it. They don't care. It isn't their product, and isn't their problem. They'll just take your money, and if it blows up later they'll point the finger at LN, and you end up being a pissed off owner "venting" here on the forum about how junky the LN parts are.

Its plain and simple: Engines that are pre- qualified and see an IMS Retrofit live happy, long lives.

The 700 engines that we've retrofitted without a single failure of the replacement bearing is perfect evidence of this.

Paul Waterloo

Jake:

So if you find the cam deviation high (for example, my car is 8%), therefore, it fails the pre-qualification process. What I read is that any item that fails that can be repaired and it is repaired, such as replacement of the wear pads and ensure everything is in spec, and then we can move forward with the IMS bearing change out.

Obviously if the engine has metal floating around in it, it's a completely different story with the pre-qualification process.

So am I right with my assumptions above?

Charles Navarro

We will probably be the most expensive shop you can use for this process, same as Flat 6 Innovations. What you get with us is the experience and expertise of being the developers of the product and procedure. We won't cut corners. Pre-qualification is required for any warranty. If the shop doing the work doesn't do this and you have a failure, there will be zero warranty.

And yes, we have seen cars with low mileage that have all kinds of problems that would disqualify them from being retrofitted. Shops on our Preferred or Certified Installer lists are required to pre-qualify jobs and have turned down repair work repeatedly because they find engines that are not suitable candidates for our products and procedures.

We also quote out what it will be worst case - every time, regardless of mileage. You never know what you will find once the car arrives. I'd rather prepare you for the worst and then the job is thousands cheaper on the back end once we actually have the car in our facility and we can thoroughly inspect it. Doing it any other way is wrong and what companies like Motormeister used to do - quote low to get you in, then sell you stuff you don't need once you are trapped.

To flame my company and reputation because you want to be cheap doesn't settle well with me. Go have Jiffy Lube put in your IMS bearing if you want someone blindly changing parts that doesn't know what they are looking at or know what they are doing.

Gonzo911

OP...this is the equivalent of seeing a heart surgeon that tells you, "Sorry, I won't operate on your heart unless I know it is 100% normal. I can't risk my reputation if you die on the table."

So, these guys made some money developing a replacement IMSB that will only be used to replace a perfectly good (make that "perfect") IMSB, in a perfectly good engine.

It's funny, but I don't recall the need to "pre qualify" these cars for an LNE IMSB when I first bought a 996 years ago. When I had mine replaced it certainly wasn't a requirement. This pre qualification requirement seems to have crept up now that these cars are getting older/higher mileage and a few of these replacement bearings have failed. This way, the blame can't be placed on the replacement bearing. It is simply because the car was basically dead on the table before the bearing was installed.

jaetee

Keep in mind that less than 1% of dual row bearing mk.1 996's made between 1997-2001 were affected by the IMSB issue! The mk.2 996's (2002-2004) with signle-row IMSBs are the ones that had the higher than 8% failure rate.

Check the build date for your car. It's shown as month/year (10/99 on my car) in the upper right hand corner of the sticker on the edge of your driver's side door. As a 2000 model year car it is more than likely built in the first half of 2000, which means it more than likely has the more robust dual row bearing. The gradual changeover from dual-row to single-row bearing started in mid-2000. And even quite a few 2001 cars have been reported to have dual row bearings come out of their car during swap.

Knowing what I know now, in your case I would not change anything just yet and start with buying an LN Spin On filter adapter, a magnetic drain plug and a 100 micron strainer to run your oil through during oil changes. Over the next couple of oil change cycles, send oil samples off for UOA (used oil analysis) and such and keep a watchful eye on debris in the strainer and in the oil filters you change out.

Watch for plastic bits in the oil as well, as these will most likely be coming from the chain tensioner paddles. If the oil is clean of plastic, I'd leave the chain tensioner paddles alone too. Overall, this could mean the difference between doing the more costly engine-out refresh vs. a more reasonably priced tranny-out IMSB/RMS/Clutch swap when the time comes.

When your clutch starts to show signs of needing replacement, then you will have some big decisions to make. Put in whatever flavor of replacement bearing your research points you too, or what your wallet can support.

When I had the full engine-out refresh done to my 2000 Cab last year I went with the EPS "Eternal" cylindrical bearing with the slotted hex drive oil feed and put almost 6k miles on it before selling the car. That car had an 05/00 build date and the IMSB that came out at 93k miles was dual row and in perfect condition. EPS advertises their cylinder bearing as a permanent fix and there is no evidence that I could dig up that indicates anything to the contratrary. Granted, using the $450 EPS bearing kit instead of the more expensive LN options went against the general mindset of most who frequent here, but I would still use that bearing again in a heartbeat. You will hear things like "there is no published spec sheet for the load capacity of the bearing" and "there are no published numbers of how many bearings EPS has sold" or "EPS probably doesn't sell enough bearings for us to have heard of any failures yet" and other potentially valid-sounding arguments as to why not to use the EPS bearing. Take all of that into consideration.

My theory is quite simply that most people who chosen to use the EPS bearing don't frequent Rennlist. But if their were failures, I think it's pretty likely in this day and age of easy-access information that we'd have heard about it by now.

Now.... None of this is any kind of slam against LN or their solutions. In fact, the car that replaced my 2000 Cab has an LN dual row replacement bearing in it, which was replaced under previous ownership. But that bearing also has a published 50k mile life-cycle and in the unlikely event that I should happen to still own this car when it's "time" to go through another IMSB swap, based on what I know right now I'd use the EPS Eternal bearing again without hesitation.

AWDGuy

That car sat for long periods of time. No oil circulating, means stuff wasn't seeing any lubrication. Those plastic pads were brittle on my 02 C4S with 100k km on it. I can imagine the pads in your car being even more brittle since it saw very little oil circulation.

And yes, If I could afford to have LNE install a part they had a part in designing in my car, I'd do that rather than have some parts changer shop install it.