IMS job half-done - My IMS was perfect when removed.
 

Just finished the first half of my clutch / IMS job using Pelican Parts' kit and LN Toolkit. I have been following the Pelican directions, so have not locked out the crankshaft but have marked the cams on my single-row, 5 chain 3.2 motor. My rear main seal was leaking, but the IMS seemed perfectly good when pulled. $160 isn't a a lot for insurance I guess, but the whole job seems like a big PITA to replace a good part... not that I can go back now.

Everything has gone well so far. I have the bearing and tool in freezer now, as per Pelican guide. The cams are marked, however I only was able to get to the two exhaust and the back intake cam, so the front intake is not marked (misread which ones should be marked), but am not too worried about this. Any suggestions as far as installation and reassembly?

Black Box,

How many miles on your 2000 S and what would you say has been the driving style little Black Box has experienced? thanks

I'd be willing to bet that a destructive inspection of the bearing would prove that the bearing was beginning to wear. I have yet to see a "perfect" bearing removed from an engine.

Don't all engine components wear?

Pried the IMS apart with a flathead....

it was completely filled with motor oil, not grease. Don't know what this means for it's lifespan, but I guess it means it's not such bad thing it's replaced now.

The engine has approx 45k miles, with at least the last 25k being pretty hard (driven as intended, high RPMs and hard braking).

Anybody can justify anything but 45k miles is too soon. That is why I bought the IMS Guardian. So it will be give me forewarning!:):):)

If you were really interested in providing a data point, you could send out your original bearing for non destructive testing. You could google "non destructive testing" in your area, or call an aircraft maintenance facility in your area and ask them who they use. It would be a very interesting data point to have, given that we know that the seal had failed.

I've already pulled the seal and washed it out. Does that matter?

I'm not sure what they'd tell me'. There was not a single piece of metal inside, it feels exactly like the new pelican unit. No play and just as smooth

No, NDT test the condition of the bearing surfaces, not the the lubricant.

No grease and motor oil as a replacement? Would think that was not a good thing since bearing was suppose to be sealed and require no additional grease.

Reckon frequent oil changes and "proper" driving style saved the day for you.

Additional question: Was the original a singe or double row bearing?

I also own a 2000 S and as I understand it, 2000 was when Porsche used single and double row. Dis-assembly only way to be certain which one might be in use.

Perhaps someone else could shed more light on that fact or fiction.

Don't judge a book by its cover..

Stage 1 failure had already occurred and that nasty black oil that was found inside the bearing is proof that the outer seal had already failed and allowed engine oil to wash the permanent lubricant away. This is what starts the snowball headed to hell and we have known it for years.

Your bearing had already failed.. But it felt fine? Yep. The difference was that collateral damages are not symptomatic until stage II bearing failure.

When the seal fails the degradation has begun already..

My 2002 carrerra 4 IMS failed at 46K which I find absolutely reprehensible for a a high priced performance car. Never tracked and always carefully serviced. The last service was less than 2K miles before it self destructed with no debris having ever shown up in the filter and no other symptoms. Happened at 60 mph on a PCA outing. From the porsche dealer all the way to porsche customer service rep, everyone was very sympathetic but said that because it was out of warranty that was just tough. $20,000 later I was back on the road. Due to the number of failures of this part, I see this as a design flaw and a failure of porsche engineering to address it. It would appear that the only safe way to protect yourself is to spend $2K every 25K miles to put in a new bearing just in case. After venting a bit, let me say that I bought my first porsche in 1964 and I currently have three of them, so I have plenty of brand loyalty. I just feel that porsche has let us down in this situation. I now have 25K miles on the new engine and I really don't feel secure that I won't have an impending failure with it soon.
From my reading about the guardian a significant number of opinions are that when you get the warning it is probably too late to save the engine and you are still looking at a rebuild, but you have maybe saved the core. Are we better off just to have a milage schedule to spend 2 grand to put in a new bearing. If so, what milage would be safe?

There is no such thing as absolute safety. In any engine or transmission or any other part. They all fail sometime..its just luck when. As to when they fail...anywhere from 6k to 250k in postings I've seen.

I don't know where you got the impression that the Guardian would only warn when the engine was toast. I know the testing of the Guardian included the insertion of a IMS bearing known to be going bad in a perfectly good engine, the installation of the Guardian, the driving of the car until the Guardian signaled a problem and then the examination of the bearing condition. The engine was saved. You have to stop when the buzzer goes off, yes. But the intent of the Guardian is to catch the problem early enough that you can save the engine.

Your replacement engine (if from Porsche) certainly also has a design/materials-flawed bearing. Which one you wouldn't know until you had pulled the transmission off and inspected the IMS area. So if you are feeling insecure, you could go get one of the LN bearing kits installed and have greater assurance. You could do it either as a preventative measure or when the Guardian told you you needed to inspect the bearing condition.

Unfortunately, if Porsche put in a new engine, chances are they put one in that the bearing is not easily replaceable. It will cost alot more than $2k as you would need to split the cases. Yes the guardian in your case would be very useful as the alert would save your engine from failure.

This is completely untrue of any design...it may be true with 986/987/996 models. But there are plenty of machines out there that if properly assembled with non defective parts have incredible reliability rates. Boxsters are an absolute ball to drive, but far from a design tour de force in terms of reliability...in fact they're pretty piss poor IMHO...

Well Shad, my experience differs. I've owned/controlled-the maintenance-for an average of 3 cars for the last 53 years and had everything from a Plymouth, Dodge (4), Pontiac, Alfa, Acura have a major internal mechanical failure resulting in the need to rebuild or replace the engine or transmission. That doesn't count probably 30 cars replaced for premature rust reasons. Or others which were just generally so unreliable and unfixable (914) I gave up on them. I maintain the cars better than the manufacturers ask and still there are random failures.

Yes, I had a secretary who had about 400k on her 4-cyl Pontiac with the original clutch and never any internal engine work. Her driving style and the luck of assembly just happened to coincide. But for every one of those, there is someone early on that bell curve of reliability.

They all fail sometime. And not just M96s.

Mike, my experience differs from yours. I've only been driving for about 20 years, but have taken 3 vehicles to well past 200k miles on original engines. When I sold my 1985 merc 190E it had 265k, the 1987 BMW 325is had 215k. 1992 Audi 200 turbo had 245k. My current DD is a Lexus GS 400 with 210k on engine and trans.

And there are Boxsters which go 200-250k. Don't judge by a limited sample. Parts that rub against something wear, simple fact of life. And they fail on a bell curve with some going for a long time and some failing on the left hand side of the curve.

I'm glad you had great luck, I haven't. My max on a motor was 105k and its replacement lasted 2k. Next motor was 15k when I junked the car (Japanese motor) because of body rust. My environment was DC 4-season urban commuting 10 miles to work, 2 to the store and 250 to grandpas. Oil every 3k no matter what the dealer/maker said. 2 Boxsters, no failures over 5+ years. Not that they couldn't have and not that others haven't failed them and not that I make too much of the statistics of a sample that size.