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Having owned 2 Boxsters, and being "concerned" about the IMS failure, I am now looking for a 997.

From what I have been reading and being "told" the Tiptronics and later 05's are not likely to have the problem, is there a production date for

when the "upgraded" IMS starts?

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2005 is the year when they moved to a larger bearing.

If you buy a 1999 model year engine from Porsche today, they will install the larger unserviceable bearing.

However I've read about potential for failure even with the new bearing.

Only the very newest model 911's come with an engine designed without the bearing.

My personal opinion is there is not enough data about bearing failure to warrant being worried about it when considering a purchase or even driving your own car.

Just stay away from early model year 1999 through 2004 ish cars - especially those with low miles.

If you purchase a CPO car, you'll have nothing to worry about regardless.

And if you want extra security, you can buy the IMS Guardian from flat 6 innovations which will still alert the driver of potential for disaster all the way up to model year 2008 - although one might question what they do if they get a warning - since the bearing is not replaceable (whole shaft) without complete engine dismantling.

Edited by logray
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To be completely accurate only SOME of the 05's got the upgraded bearing. Most did not. That is why Porsche "goodwills" enngine replacements on a lot of 05's that are out of warranty. They know there was a major problem with the early 05's. All 06 to 09 997's had the upgraded bearing.

Edited by phillipj
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Thanks for the clarification Phillip!

Some more info regarding years and which bearing they have:

"All MY97-99 vehicles with their original engines will require a dual row retrofit kit. MY00-01 vehicles may need either a dual row or single row retrofit kit, so you'll need to inspect the flange, as shown below to be sure which will be needed.

MY02-05 will need a single row retrofit kit, although depending on how late the build date was, there may be some MY05 vehicles with the updated M97 IMS, which is not serviceable, at least without teardown of the engine.

If your vehicle has a replacement engine, expect to find the prevailing bearing used by Porsche in those years. If the engine was made for MY06 or later, it will have the late revision, larger IMS bearing which is not serviceable."

Courtesy http://www.lnengineering.com/ims.html

I have also seen some threads recently about new Porsche engines (including rebuilt or new original M96 engines) having the larger non-serviceable (without complete teardown) IMS bearing.

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Thanks Logray.

Great info. It would be nice if Porsche would have used the updated bearing in ALL the 05"s. They knew there was a problem and just waited til they HAD to do something about it.

How is your car running? Did you get any clarity on the Loctite issue you had from the rebuild?


Edited by phillipj
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Thanks Logray.

Great info. It would be nice if Porsche would have used the updated bearing in ALL the 05"s. They knew there was a problem and just waited til they HAD to do something about it.

How is your car running? Did you get any clarity on the Loctite issue you had from the rebuild?


Hey Phillip,

Yes, I wish there would be a mass Porsche recall for the IMS, but with an aftermarket solution available, doubt it will happen (did Pelican ever get their solution going as well? less expensive IMSB).

HEY the car is RUNNING AWESOME!!!!!!!!!!! I think there is a lingering issue though with either too much fuel in bank 1 or perhaps worn piston rings in the entire bank. I'm not tearing into the car again at this point.

Funny you should ask about the loctite. When I was tearing the engine apart I damaged my bank 1 variocam actuator. It failed about 1 week after I reinstalled the engine. So last week, out came the engine again to remove the cam cover and replace the solenoid. When I buttoned everything back up I went ahead and used BLUE loctite on all the internal hardware. And since the engine was dropped again I removed bank 2's covers and loctited those as well.

BTW did you want your stuff back!!!! ????? THANKS AGAIN!!!!!! :-) :cheers::cheers::cheers:

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Is there a build date after which all 05 engines have ugraded IMS bearings...Porsche knows, does anyone else?

Well, maybe I just need to look for an 06.

You see though, even the updated IMSB in the 2005-2008 cars is only as strong as the original 1999-2000 dual row. It too can fail... it is an inherent design issue with the M96/M97 engine.

"Engines replaced or vehicles purchased in or after MY2006 [and some MY2005's] should have the revised, larger single-row IMS bearing, identifiable by a larger 22mm nut in the center of the IMS hub flange. This uses a very large 6305 single-row bearing with a load rating similar to the dual row 6204 bearing compared to the earlier single row 6204 bearing which has about 2/3rds the load rating of the 6305."

Again though my two cents is to not let it get to you... there aren't enough statistics, and while there are some failures out there, some of it is real and some of it is smoke.

IMHO I would rather have a serviceable bearing that doesn't require total engine tear-down and buy the IMS Guardian from flat 6 in order to get pre-preemptive failure notification, then retrofit a bearing if I need to. In some percentage of cars over 85% (my own guess), their bearings could last forever.

If you really want to get away from the design issue you need a 2009+ car.

Edited by logray
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Wow I'm sorry you had to pull the engine again! You must be getting quite good at it by now! How fast Were you able to get it out?

No, there is no need to send me that grease back. I'm sure there will come a time when another member is in need and you can send it off to him or her.

Great to hear that your car is running strong. Good job and I'm still so impressed that you tackled that project with no experience!

All the best..


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The first time I spent a whole day dropping it.

The second time, about 4 hours including short lunch.

It's actually pretty fun to do once you've done it before.

Thank you again, Ill keep an eye out for those in need.

Does the trans have to come out as well?

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