Is there truly no way to tell that it’s time to replace the IMSB?
 

There has to be some tell tale sign that the bearing must be replaced otherwise, 100% of Boxsters and 911s of a certain vintage have to get this work done. Didn’t Porsche claim only a minority of cars are afflicted with this issue? How can they know that if there aren’t signs to foretell doom ahead?

You have A LOT of reading to do.


.

Cut open your filter to check for ferrous particles, start doing used oil analysis......this is the way to tell.


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An issue that has been blown way out of proportion by the web.

Correct.

There is NO WAY TO KNOW.

Its a lot like the Heisenberg Principle - if you actually look at (inspect) the IMSB then you might as well replace it anyway. :D:D:D

Cutting the filter open or oil analysis will provide information about the entire engine, not exclusively the IMSB.

Your conscious is your guide

Remove your airbox and cut it open. There should be a sticker inside that will illustrate where under your car you should look for the hanging tag that will identify which model IMS you have, and how to remove and inspect it.

Or, follow Particleweave's advice.

:D

File this post under 'Wild Goose Chases'

Starter is just messin' with ya cantdrv55.

There are dozens and dozens of threads here and on other Porsche sites so just do some searches and settle in for a Sunday afternoon of reading. The whole IMS discussion proves the adage 'A little knowledge is a dangerous thing' so educate yourself and gain a lot of knowledge on the subject. In the mean time drive your car.

Look at your cam deviations as an indicator of IMS health. There was an excellent article in a west coast Porsche mag, I have posted in this forum on this, also check out this link. Cam Deviation to Detect IMS Failure Progression - Pelican Parts Forums here is the url from Pedro’s
http://pedrosgarage.com/Site_5/Good_Vibrations.html
Rick

Yours could fail with no warning tomorrow. Yes.

And by the time you can detect debris in the oil filter, you have to understand that debris and even smaller and more deadly particles have been circulating within the engine against many bearings for maybe hundreds of hours. Some installers won't replace the IMS bearing at that point because of the probability of future failure. They insist on a $$$$$ total engine rebuild.

Every engine has wear where metal rubs against metal. Your best defense is an excellent lubrication history. But what are the odds that your car had that? Did you see the 3k intervals paperwork proving such a history before you bought?

Cam deviations can be caused by many things. If you see them, get the forensics begun.

I bought a 2003 S new and didn’t know about the IMSB. About 6 years and 42,000 miles into it I learned about it and had the LN single row pro installed. The original IMSB was still fine and I still have it. A year ago at 77,500 miles the LN unit failed. In my case, everything was fine right until it wasn’t. It was caught before any major damage occurred. In terms of failure parts my rebuild only required a new IMS, one broken timing chain paddle and the oil pump internals. The crank, block, cylinder heads, rods and pistons were all fine but I decided to have it increased to a 3.6 for the rebuild. The oil cooler and hydraulic lifters were also replaced as a precaution and all the other usual rebuild parts and gaskets went into it.

So my point if there is one is that the IMSB is fine until it isn’t and if you’re lucky when it goes the engine will be rebuildable.

A LN IMSB failure?
IIRC, there have been claimes than none have ever failed. I could be wrong.....

Haha! :D

I used to keep count...I think I saw around 15-20 different complaints of LN IMSB failures before I quit paying attention. Of course, those failures “had nothing to do with the bearing and was the fault of the installer, crank runout or other engine failure”.

Some of those users reporting failures were even banned from rennlist because they dared to question LNE. :rolleyes:

Oh you're not wrong..... there have been LOTS of claims.... but they're B.S.

As I've done with several other claims made by "the religion", I've read extensively on this topic, and in that reading I've found dozens of failed LN IMSB's.

Don't drink the cool aid.

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I have owned a 2001 2.7 Tiptronic Boxster for 3yrs now, and I had a major service carried out on it, the mechanic found ‘material’ in the filter, a lot of material. The mechanic thought it was the IMSB, and the material looked like alloy chips, but being a retired Aircraft Maintenance Engineer I did my own investigation. To cut a long story short, I removed the IMSB and it was a factory fitted dual row bearing, and it was in ‘as new’ condition, even the plastic seals looked new. Turns out the problem with my engine was not the IMSB, but another little discussed problem that affects the Boxster engine, my ‘Cam Chain Tensioners & Variocam Tensioners’ were shot. This in turn means that the cam timing is erratic at best, and dangerous at worst, when the Cam Chain Tensioners go it leaves the chains to basically ‘flap’ about untensioned, this in turn can put stress on the IMSB. Porsche should have made the Tensioners a regular service item, but they didn’t, my car with 147,000km on the clock, had three out of the five Tensioners fail. If you’ve heard of the ‘NORMAL’ chain rattle at start up or when the engine is cold, this is a lie! If the Tensioners are operational then there is no rattle. So the IMSB is not the only thing responsible for engine failures.

I've got that startup rattle. Arghhhhh. My reading reveals that I would be ill-equipped to replace the three tensioners.

Think I'll get a Mother Mary to stick on my dash and, no, I'm not talking UFO.

If you had a Durametrics and monitor the Cam Shaft deviation that may give you a perspective on a couple item. Chain rail condition, tensioner condition and IMS. That with oil filter inspections. are a good starting point.

Well all I know is mine failed. Prior to the failure my shop told me my used oil filters and magnetic drain plug were always clean of debris at each oil change and without going through my records I would say that my oil changes were every 5,000 -7,000 miles at most. My oil was always changed at least once a year and always after 2 track events, and always with Mobil 1. In one of my other threads on this topic, someone said ceramic ball bearings in steel races are a bad idea, and I think there is some merit to that. The ceramic balls are much harder than the steel races. Since the bearing is open and relies on splash lubrication, if there are any foreign particles in the oil and they get into the bearing races the ceramic balls are just going to grind them into the races until a failure occurs.