years of IMS concern

[KawasakiTriple]

As a new member, everyone has been great. Only my second post.
As I am reading everything I can get my hands on, Ref: 911 years to buy, avoid etc. The one questions seems to remain. Which years did the dreaded IMS bearing exist. Some say, 99-2005, some say into the early 997 model years? Some say that to avoid it all together, only look at 2009-2011 direct injection models?
Can anyone shed some light on the issue. I may look at an earlier model, and replace the bearing with a new one. But, Would just like to know. Thanks Robert TN

[shamrok]

The bearing was redesigned sometime in 2005 and was fully eliminated in 2009 models. All 2006-08 models had the redesigned bearing with much better reliability, whereas 2005s are more difficult to figure out and IIRC, you can't tell unless you separate the gearbox from the motor (e.g. during a clutch job). With regards to the water-cooled cars ('99-present), Rennlist is likelier a better bet for info. Lots of threads over there about the IMS.

[175K911]

IMS concerns span the water cooled Porsche ‘97- ‘08 though as stated above the ‘06-‘08 are less of a problem. Keep in mind that ‘97-98 were Boxsters, then the 996 started with the ‘99 model year.

Of course if you find a car that’s had the repair done, either the factory or better yet the LN Engineering kit, then it really is no longer a concern.

[da Vinci Dan]

You would get more feedback asking this question in one of the water cooled sections.

[jlex]

Except for the turbo models, I believe.

[Driver8]

These should help explain the IMS issue.

https://www.youtube.com/watch?v=i14LKvAW-So

https://www.youtube.com/watch?v=7fcPspA-4BU

https://www.youtube.com/watch?v=hX2k6b0ywGc

https://www.youtube.com/watch?v=I0dqyvvf8uw

[Driven97]

Originally Posted by jlex

Except for the turbo models, I believe.

And gt3 models also have the old school mezger block without the questionable IMS bearing.

For US market 911s (non turbo or gt3):
'99 dual row, low failure - yellow status
'00-'04 single row - red status. Replace with aftermarket bearing.
'05 - transition year, crapshoot
'06-'08 - solution bearing, low failure - yellow status
'09+ - redesigned engines without sketchy bearing - green status

[KawasakiTriple]

Thank you all for the clarity. Now it's a looking and decision making process. Thanks again!!! Great site.

[Peter Zimmermann]

Please remember that '06-'08 models, when the bearing must be replaced, require a case split to do the job. The bearing used in those engines is too large to replace without complete engine disassembly.

[KawasakiTriple]

Peter, just read your recent post about the 2006-2008 (997) bearing. I had no idea, thank you. That's actually worse than the others. One dropping tranny and the another pulling and splitting cases is an entirely different story. tks so much. Robert TN

[Matt Monson]

It's overblown. I think the official number from Porsche is less than 10%. My engine went 175k mi before it failed...and by failed I mean the engine. It broke a valve spring. The original stock IMS was fine. 2006 Cayman S.

[MBAtarga]

Originally Posted by Peter Zimmermann

Please remember that '06-'08 models, when the bearing must be replaced, require a case split to do the job. The bearing used in those engines is too large to replace without complete engine disassembly.

I thought the '06 was the only model requiring the case split.

[LakeCleElum]

KawaskiTriple: H1 or H2? I recently sold an H2.....

[KawasakiTriple]

Sir, On the triple issue. I love them. Have 3 H1's 70 H1A, H1B. H1E and am currently rebuilding top to bottom, a 1973H2A 750. They are a blast. Only sad part is I just turned 66YOA. But, still have fun.
Always wanted a 911, However, after reading cover to cover, Porsche 911 Buyers guide by Randy Leffingwell, I kind of got discouraged with the earlier air cooled versions as a ton of things seem to need addressing. Where the later water cooled ones seem to be a lot more reliable. Anything you could share would be great. Thanks Robert TN

[Jeff Alton]

Originally Posted by Matt Monson

It's overblown. I think the official number from Porsche is less than 10%. My engine went 175k mi before it failed...and by failed I mean the engine. It broke a valve spring. The original stock IMS was fine. 2006 Cayman S.

This ^^^^^^ Matt is exactly correct. You are as likely, or more likely, to suffer a different failure before the IMS bearing fails. Yes, they do fail, and it is bad when it does, but there are other issues to worry about...

The failure rate of the larger bearing is hardly even measurable. Like a handful....

[Nick Triesch]

So Jeff, are you saying an 08 Cayman has a pretty realiable IMS bearing? I have not heard of any Cayman cars lose an engine . I have seen an older 911 and Boxster have IMs huge problems . The reason I’m asking is there may be a 08 Cayman in my future. Just fun great cars.

[996AE]

Seems 2008 cars are less than 1% failure rate reading the boards.

Pretty rare. Bore scoring more real threat 2006-08 cars.

Life is a gamble.

[Driven97]

Also I've heard oiling is sketchy on the track prior to 09, so if you're planning on track use...