jmj951

Well, to be fair, you went well beyond that to insinuate that this bearing problem is an overblown fabrication designed to make money off of peoples' ignorance and is not worth the trouble to address preventatively.

Your financial analysis isn't comparable to what we see in North America. A complete bearing failure essentially means a completely ruined motor, with few exceptions. A new motor from my local Porsche dealer is $24k installed. Preventative maintenance EXCLUSIVELY for the smaller, replaceable IMSB would be less than $3k (under reasonable circumstances where you can drive your car to a nearby specialist).

The cost ratio can change significantly if you buy a rebuilt or salvage engine. The cost of preventative bearing replacement can go up significantly if it's a later engine with the larger bearing or you decide to do a LOT of other 'while you're in there' jobs, such as chain tensioners, AOS, coil packs, clutch & RMS seal, etc. etc. Many of those usually need to be done anyway.

Dealing with an engine failure would be financially impractical to a lot of 996 owners in the US. We see a lot of 986's and 996's go to salvage due to motor failures because of a combination of the cost to replace the engine and the decline in value.

The question/gamble is, can you realistically recognize an IMSB starting to fail before it damages your engine? I couldn't, I only had a suspicion that there was a problem due to oil leakage on the case in that area of the engine. I just got lucky that I had to take my engine in for unrelated maintenance, and the shop recognized that my IMSB had almost completely failed. They opened the case and pulled out the IMS assembly in one piece so we could see its true condition before the bearing was removed from the shaft ( ). Mine probably failed because the car sat a lot, due to circumstances beyond my control (moving around a lot).

With regard to your question about failure vs. mileage, there is no direct correlation and you'll never find any hard numbers, but the anecdotal evidence overwhelmingly shows the opposite of what you'd expect - that a rarely driven car is more likely to have an IMSB failure than a regularly driven car.

TempleCloud

Yes, I agree. With your risk/reward ratios changing the bearing is a no brainer and it seems there is a difference between the US and UK. Changing the bearing over here costs a great deal more, yet the repair of a failed one appears to be cheaper.

The garage also mentioned that one of the problems is caused by Porsche themselves advising long periods between oil changes, especially early on in the engine life. Seems you can help things along and do preventative maintenance by changing the oil more frequently, especially early on.

As others have said, its a crap shoot but I still maintain its wise to be cautious, particularly when it comes to choosing the garage to do the IMS work.

krazyk86cu

Just purchased a 2002 C2 Cab with 51k miles. The IMS bearing failed at 22,389 and the engine was replaced completely in 2012.

NIACAL4NIA

So the 2002 Porsche ims failed at 22k miles and engine replaced in 2012 that makes 2200 miles per year in 10 years. Something fishy about this Krazy post.

greenjt

I'm fairly certain I know this car and the story is legit.

rudydude

Further proof that these cars need to be driven.

AK from RSA

Hi
I bought my 1998 C2 Tip with 92 000 km. At 95 000 km i fitted the Vertex IMS fix. Old bearing looked good as new. At the same time i did a trans fluid flush.
Now the car has a whine like a spaceship. Not a loud whine but just a slight irritating whine from the rear of the car. Tech cant figure it out.
Not sure if i should have just left it alone and not fiddled.

krazyk86cu

I have the dealer invoice for the work. The car was in CT at the time.

krazyk86cu

I bought this car with the intention of it being a weekend warrior but I'm finding myself leaving my Mustang at home fairly often now.

lomax

I guess it is time for me to chime in here. A new to me 1999 996 C4 with 48K miles and the shop just called and said that the IMS was in the process of failing. It has the dual row bearing in it. I am glad I decided one of the first things I was going to do on this car was get that done. Costly engine repair avoided.

Marc

alpine003

If you ask them to check the IMS, of course a lot of shops will tell you it's failing to get the extra guaranteed work. I mean what consumer is going to reject that work order or diagnosis, whether true or not. You should always ask for the original bearing back so you could inspect it yourself.

These types of tactics further skews these types of polls, rendering it next to useless IMO.

Flat6 Innovations

if an engine does have a failing IMSB, then that engine is disqualified for retrofit.

lomax

I absolutely inspected the bearing that was pulled out of the car. It is a bit loose and was doomed for failure in the near future. I had asked that it be replaced anyway as a preventative measure but am very glad that I did. You do have a good point that if someone just wants it inspected and not replaced that the shop could take advantage. I personally don't know why anyone would want that anyway as if you are already in there just go ahead and replace it

Marc

FastM96

02 C2 just turned 59K, no issues. Planning roller IMSB retrofit with oil pump feed this Summer when performing clutch and RMS service.

ZuffenZeus

Actually, everyone needs to read Krazy K's newest post. Apparently, his nice low miles CS4 gave up the ghost at an intersection. He only had the Porsche for three weeks and had it towed back to the dealership which states it was catastrophic torque converter and transmission failure. A "$25,000 repair for a car that was just purchased for $26,000"... I wonder if his mustang is snickering in the background?