2005 997S large IMS bearing question
 

Hi All,

I have a 997S that was built in June or July of 2005. About 40K miles on the car at this point. I'm not absolutely sure which IMS is in the car although I believe 2005 was a transition year for it and that probably it has the larger non-removable bearing as it was built almost at the end of the production year. I asked the head tech at a large Porsche dealer whether he had ever seen a car with the larger IMS fail and he said he had not. I would appreciate the collective experience of the group with this question also - and also if failures of the larger bearing are indeed that rare, whether I should have the Direct Oil Feed (from Pedro's Garage) installed without a new bearing as a preventive measure. Or just have the seal removed.

Thanks in advance for any opinions or experience.

You might get some response over on the 996/997/991 forum. I'm not sure how many regular posters to this forum have any experience with 997's. Most of the talk on this forum is about air cooled engine issues.

Agree, and also have a surf onto Rennlist and 911uk forums. My Brother and I investigated all this about a year ago when he bought his 2005 C2S. IIRC I don't think there's any definitive or absolute type of IMS that is 100% fault free until you get to the 997.2 gen engines with DFI.

[cynical mode=on] With topics like this, whenever a head tech denies that they've seen this issue before, I instantly just think "muppet" or they're towing the party-line.....especially with such a prolific issue such as IMS and it's huge amount of coverage on the web....

The bigger concern is the bore scuffing on the 4-5-6 bank, and for that have a Google for Baz Hartech. Hartech have a remedy, but he/they've also extensively documented their investigations.

Thanks for the suggestions. I'll follow up on the other lists/forums suggested.

Spenny_b is correct in saying that cylinder scoring is a bigger concern. We are seeing this more and more frequently first hand.

There are plenty of solutions to repairing this available. We have used Nickies (3.4-3.8 conversion) and we just did a 4.0 with an iron liner sourced through EBS. We will be doing a 3.4 Cayman and another 3.8-4.0 conversion on motors with scored cylinders this fall.

As far as the larger IMS bearing failure goes... We have never seen one, and I am not a muppet. That said we have heard of engines locally with problems diagnosed as a failed larger bearing, but never inspected them, and never seen a diagnosis report that was definitive. Large bearing IMS failures are rare, period. Yes, some have failed, but it is rare. The direct oil feed products are interesting, but I am not sure they really solve and issue.

We recently pulled a part a 3.4 dual row motor that was diagnosed with an IMSB failure, only to find the timing chain let go... So there is plenty of hype and perhaps some mis diagnosis going on.


Cheers

No offense meant, Jeff....I was referring to main dealers as opposed to indies, my bad, I should've been clearer....it's one of those "boil my piss" topics where anything to do with any sort of warranty or manufacturer liability is met with instant denial, which to me smacks of complete ignorance....seen it numerous times with VW, now with BMW and of course Porsche. Grrr.

Agree with misdiagnosis and internet hype though, too much of the other extreme assumption-diagnostics.

Most of what I wrote was tongue in cheek, no worries :)

But, I do tire of the hype given to the issue especially when there are times when a misdiagnosis took place and yet the fear continued to grow!

Cheers