The DOF, or Direct Oil Injection, does appear to have many benefits that may lead to much longer bearing life. It shoots a small stream of engine oil directly onto the ball bearings, providing much more lubrication, cooling and cleansing. If I had to change my IMS bearing today, I would probably install the DOF too.

I have been studying the bearing from a slightly different angle. My objective is too reduce the occurrence of catastrophic bearing failure, which leads to catastrophic engine failure. I can certainly live with bearings that wear out, they will give you plenty of warning as they do wear. Humming, buzzing, vibrating, all clear signs to their worn condition. It is when the bearing completely comes apart that will cause catastrophic engine failure.

What holds the bearing together is the ball cage, also known as the retainer or separator. It is the cage that keeps the balls in place and keeps the inner race of the bearing centered inside the outer race. When the cage comes apart, the inner race is free to dislocate, smash into the outer race, and let the timing chains slip on their sprockets, leading to catastrophic engine failure.

If you are not familiar with ball bearing construction, you can look at it as a shoe. If your shoes keep falling off, do you blame the shoe? Do you call it "shoe failure"? Or do you look at the shoe laces.

If a ball bearing cage could be built that will not come apart, even after bearing wear has occurred, catastrophic engine failures will not occur. A new bearing will just need to be installed.

Here is some info I found on the Internet regarding this subject
(http://www.volks-apart.com/page.php?...te+Shaft++Upgr)

"The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components."

It appears that this information concludes that it is the cage failure, or separator, that ultimately cause catastrophic engine failure.

I'm caving to my anxieties and having an IMS bearing replacement wrought upon my newly-acquired '04 base Carrera. What is a reasonable expense for the work I cotemplate?

Prices going up? 996's are the cheapest I have ever seen them now. After my buddies ownership experience you couldn't pay me to own one of these cars. These cars were doomed from the moment the engineers designed them. Of course this is all my opinion. Lately, Porsche's engine longevity has been nothing short of laughable. Cayenne's have scored cylinder issues (non turbo v8), then you have IMS / RMS isuess in a variety of 996, 997, and Boxsters. Doesn't really inspire confidence in the brand.. It's a shame to because these cars are wonderful to drive!

list car for sale
 

Do I have to have pemium membership to list a car for sale? If not, where on the site do I go. Sorry I cant find this out?

Rreichek

I'm trying to list a car for sale, but don't know where to go to list it. Do I need premium membership first?

Yes, you need a member to post for sale items.


Danny

Hi All,
I've just purchased a low mi Carrara C4 cab w 29K mi. This car has not been "enthusiast" owned. It's my first porsche in twenty years having had two 928 5 speeds that I used daily. I'm concerned about the ins issue and would like to find someone in the SF Bay area that is well versed in replacing the bearing with LN type. If you have some shop to recommend I'd like to talk to them. Thanks for all replies.

Very smart move on your par to get the LN bearing. I would call LN and see if they have anybody they can recommend! Good luck!

Good idea, I also would like to find the right tech for all maintinence work. Anyone with a SF Bay area favorite? I'll need the 30K mile work and will add a new clutch when the bearing is done. I'll certainly call LN tomorrow for their input. Thanks

Hello everyone,

I was a proud owner of a 911 40th anniversary limited edition Porsche until last month when couple things went wrong until a complete break down.
This car has done only 64,000 km and was mostly used as a weekend car. It has full service history and had no issues in the past until last couple of weeks when it left me dead 3 times on the road in one month.

First I had a dead battery which was replaced, then 2 weeks later the alternator died, again it was replaced. And finally 2 weeks after that, the car just stopped in the middle of the road with no warning signs.
I took it to my Porsche dealer and they came back to me after one week saying the engine has failed and in best case scenario, the Intermediate shaft with some other parts has to be replaced. In worst case, I will need a new engine.
I let them open the engine and it took them 10 days to state that the Intermediate shaft failed and the ball bearings caused more damage to the engine. The expense to fix it is huge (about 75% of a new rebuilt engine).

My question is to you - why has there been an engine failure after only 64,000 km if all the maintenance has been done regularly? Porsche engines are built to last! I was hoping for this one to make at least 150,000 without major issues.

Thanks for the help.

Petar

My understanding is that approximately 8-9% of 996 engines are affected by the IMS problem. There have been a few improvements made with respect to aftermarket bearings that greatly reduce that percentage. However, I myself am only researching before I buy.

If I go the 996 route I think the first thing I'll do is have the RMS inspected and the IMS replaced with an aftermarket unit.

Sorry to hear about your car bud. :(

Just wanted to say that woke up today and my IMS was fine. ;)

does anyone know of a class action suit covering earlier 996s regarding IMS, I have a 99 with as yet no problems

I have a 1999 with 132,000 miles. Original clutch, rms, and IMS. I am going to drive it until the wheels fall of. The whole catastrophic engine failure is a crap shoot. I think you either get an affected car or you don't. I might consider an IMS replacement when my clutch needs replacement, but for now the car runs great and gets driven hard. I look forward to continuing to drive it everyday.

My two cents: don't consider the IMS when you do the clutch - ALWAYS do the IMS bearing when you do the clutch.

In 2014 in the US, approx. 235,000 people (mostly women) will be diagnosed with breast cancer, and about the same number of men will be diagnosed with prostate cancer. If you KNOW that you have a family history of one of these diseases, or you have markers indicating that the disease is developing, do you ignore it anyway, pretend there's no chance you'll have an issue, and wait until there are debilitating physical symptoms before you finally go into the doctor and expect a miraculous cure? NO, of course not.

The same's true for the IMS bearing. You KNOW there's a chance - up to 10% - that your car might die if left untreated, and the IMSB retrofit "vaccine" can dramatically reduce your car's risk of dying from this issue.

The IMSB discussion doesn't need to involve hysteria, fear, etc...the issue is understood and preventative treatments are available, so just avail yourself of one when it makes sense to do so and enjoy the feeling that you may have just saved a life.